Ghazi Hajiri

Kévin Berger

Rémi Dorget

Jean Lévêque

Hervé Caron

Thermal and Electromagnetic Design of DC HTS Cables for the Future French Railway Network

Keywords: Analytical models, Cryogenics, DC superconducting cable, Design tools, High-temperature superconductors, Magnetic fields, Thermal and hydraulic modelling

The use of High Temperature Superconducting (HTS) cables as a technology is considered as key to increasing the power of the electrical grid while reducing the volume of installation. In addition, when transmission currents exceed a few kA, DC HTS cables significantly reduce power losses, rights-of-way and total system mass. This article describes the various studies that need to be carried out in order to correctly size HTS DC cables for the new railway network envisaged by the French company SNCF, which must consider ultra-urban needs. The process used to design DC cables for operating powers of 10, 20 and 30 MW at a nominal voltage of 1.5 kV using commercial (RE)BCO tapes is presented. In this sizing process, the critical current density Jc(B, θ, T) dependence of the superconducting tapes, the thermal properties of the materials and the different cooling modes are taken into account. Several solutions are suggested to ensure that the cable can withstand fault currents and reduce recovery time in the initial state. Finally, with the help of analytical models and industrial data, once the cables have been designed, the various system losses are reported as well as the power or size of the various auxiliary components.

I. INTRODUCTION

IRECT Current (DC) electrical networks represent a considerable portion of rail electrification in France and worldwide [START_REF] Ohsaki | Superconducting Power Cable Application in DC Electric Railway Systems[END_REF]. The transport of electrical energy in urban areas is limited by the space required for transformers and other static converters to transform electrical energy. Moreover, to reduce line losses, electrical energy is transported at high voltage, which requires a transformer substation close to where the energy is used, and the installation of a substation in a densely populated area imposes constraints. New environmental reforms also require a sharp reduction in electricity consumption [START_REF] Kriegler | Long-term transport energy demand and climate policy: Alternative visions on transport decarbonization in energy-economy models[END_REF], meaning that the French railway network has to adapt to these conditions.

In order to meet these constraints, recent developments in High Temperature Superconducting (HTS) tapes make it possible to develop cables carrying a high current density without losses [START_REF] Oestergaard | Energy losses of superconducting power transmission cables in the grid[END_REF]. Thus, the installation of a superconducting cable in Manuscript receipt and acceptance dates will be inserted here. (Corresponding author: Kévin Berger.) G. Hajiri, K. Berger, R. Dorget, J. Lévêque are with Université de Lorraine, GREEN, F-54000 Nancy, France (e-mail: name.surname@univ-lorraine.fr).

R. Dorget is also with Safran Tech, Electrical & Electronic Systems Research group, F-78114 Magny-Les-Hameaux, France (e-mail: remi.dorget@safrangroup.com).

an urban environment can be used to move substations to the periphery [START_REF] Stemmle | Three years operation experience of the AmpaCity system installation in Essen[END_REF] where space constraints are lower and to transport electrical energy directly in the form in which it will be used, i.e. DC and low voltage. Moreover, the development of coated conductors such as (RE)BCO has undoubtedly provided a better current density than the first generation of HTS, BSCCO [START_REF] Obradors | Coated conductors for power applications: materials challenges[END_REF]- [START_REF] Samoilenkov | Customised 2G HTS wire for applications[END_REF]. In addition to this, the price of (RE)BCO tapes is about €200/kA/m (according to a quotation issued in 2020 by Shanghai Superconductor Technology for a few km of 4 mm wide tapes), which is half the price of BSCCO tapes. This means that for the same cable length and price, twice as much current can be transmitted with coated conductors. Superconducting cables also have the advantage that they can be dimensioned to limit the current in case of a failure, e.g. short-circuit, overload [START_REF] Kojima | Superconducting Fault Current Limiting Cable (SFCLC) with Current Limitation and Recovery Function[END_REF].

The following section describe the sizing process of a superconducting installation for a DC cable, which always remains complex because of the numerous multiphysical constraints. In this article, a simple view of the algorithm is proposed to determine the necessary number of tapes per layer and per pole, while ensuring that the cable is protected in case of a fault. The performance of the algorithm does not stop at determining the number of superconducting tapes needed. Indeed, different design steps are discussed, and in particular the choice of cryogenic line, among which the following configurations feature: Concentric Pipes (CP), Separated Pipes (SP), and Concentric Pipes with Separated Return (CPSR), shown in Fig. 1. Therefore, the proposed design tool will also allow the selection of the cooling system and the required volume of the Liquid Nitrogen (LN2) tank upstream of the installation. This volume is directly related to the targeted autonomy in LN2, i.e. the time between two fillings tfill, considering hydraulic losses Phyd, cryostat heat losses Pcryo, contact resistances losses Pcr, and terminal losses Pter.

II. SIZING PROCESS

Before presenting our sizing method, we would like to specify that the cables studied here can be made up of several concentric layers placed in a liquid nitrogen pipe allowing cooling, H. Caron is with SNCF Réseau, F-93418 La plaine Saint Denis, France (e-mail: herve.caron@reseau.sncf.fr).

Color versions of one or more of the figures in this paper are available online at http://ieeexplore.ieee.org.

Digital Object Identifier will be inserted here upon acceptance.

D

with the whole inserted into a cryostat. Fig. 2 shows a complete view of a superconducting coaxial cable with its different layers. The "Positive pole" located on top of the former consists of several superconducting tapes including an additional copper layer. The tapes are typically 4 mm in width and the thickness of the superconducting layer is about 1 μm, with a substrate thickness of 100 μm. The number of HTS tapes of the "pole" is closely related to the determination of the critical current of the cable. The next layer is composed of an electrical insulator to electrically separate positive and negative poles. Insulators such as Kraft paper soaked in liquid nitrogen are used. On the one hand, the impregnated Kraft paper has a high dielectric strength of 50 kV/mm [START_REF] Masood | Breakdown strength of solid dielectrics in liquid nitrogen[END_REF], and on the other hand, if the nitrogen forms gas bubbles, its dielectric strength drops to 2-3 kV/mm [START_REF] Gromoll | Dielectric strength of insulating material in LN 2 with thermally induced bubbles[END_REF]. For practical reasons, the insulation layer must be thick enough to not tear, i.e. a thickness of at least 2 mm. Next, a set of HTS tapes and copper constituting the negative pole is placed on top of the insulator, carrying the same current as the positive pole but in the opposite direction. All these layers are inserted into a cryostat to maintain the temperature of the cable below the vaporization point of the liquid nitrogen. Depending on the chosen architecture for the cooling of the cable, the liquid nitrogen outlet to the cooling station can be located either outside the cable, in a separate pipe, see Fig. The first part called "Electromagnetic sizing" consists of identifying the critical current that must be higher than the operating current by considering the different cable designs. For this, a 2D analytical model has been developed for the calculation of magnetic fields on the HTS tapes in the cable. The second part of this paper consists in determining the copper thickness thCu and the thickness of a polyamide layer thpol to ensure the continuity of operation of the cable during a fault and its ability to limit the fault current, and also to satisfy a reasonable recovery time. The last part aims to study the thermal and hydraulic steady state in order to design the necessary cooling system. Both in normal operation and in case of a fault, the liquid nitrogen is maintained in the following range: 68 K  TLN2  78 K and 3 bar  p  15 bar [START_REF] Noe | Superconducting_Cables,' presented at the EUCAS Short Course Power Applications[END_REF].

A. Electromagnetic study

The DC HTS cable under consideration consists of two concentric poles. The inner positive pole carries a current +I and the outer pole carries a current I, along the length of the cable. It is important to note that each pole may have a different number of layers and tapes. A layer consists of superconducting tapes and the radius of each layer is directly related to the number of tapes on top of it. We want to calculate the magnetic field distribution produced by l layers per pole of Nl tapes when the cable is in operation. Since we are focusing on the design of DC HTS cables, the current density J can be considered as uniformly distributed between the tapes and constant in each of the superconducting parts. In the developed analytical model, the magnetic field produced by the whole cable is obtained by superposition, translation and rotation of an infinitely long tape in a 2D coordinate system.

To determine the critical current, the radial and tangential components of the magnetic field applied on each tape without considering the field of the tape itself are calculated (same principle used for the characterization of the tapes). For each simulation, the amplitude and the application angle of the magnetic field generated by the current flowing through the cable is calculated. From these values and using the tape manufacturer's data [START_REF] Wimbush | A Public Database of High-Temperature Superconductor Critical Current Data[END_REF], [START_REF] Wimbush | A high-temperature superconducting (HTS) wire critical current database[END_REF], the critical current is obtained according to the maximal operating temperature Tmax_t in contact with the tapes. Inhomogeneities over the cable length are taken into account by choosing a security margin of 20 % between the nominal current In and the critical current [START_REF] Solovyov | Non-uniformity of coated conductor tapes[END_REF], so that the critical current of the cable Ic must be greater than 1.2 In.

B. Copper thickness design (in case of a fault)

In a traditional railway network, copper conductors can handle the current in case of a fault. However, with DC HTS cables, in case of a fault as shown on Fig. 4, as soon as the fault current exceeds the critical current of the superconducting tapes, the current ICu penetrates the copper layer, which leads to heat generation by joule effect, and tends to increase the resistance of the conductors and thus of the cable. As indicated in [START_REF] Kim | Assessment of Improved Power Quality Due to Fault Current Limiting HTS Cable[END_REF], the reduction of the copper thickness thCu makes it possible to limit the fault current. This phenomenon has a great advantage: it is no longer necessary to increase the power of existing protection devices, thus saving costs and installation volume. The objective of this section is to design and determine the ideal copper thickness to minimize the fault current before the circuit breaker opens, while maintaining the nitrogen in its operating range. The non-linearity of the superconducting tapes has been considered, using the E-J power law with a critical current density that varies as a function of temperature [START_REF] Duron | Modelling the E-J relation of high-Tc superconductors in an arbitrary current range[END_REF]. The physical parameters of the superconducting and copper layers have been considered homogeneous over the length of the cable and the calculations are made according to the highest temperature of the cable in normal operation. The electrical parameters used for the French railway network are given in table 5 of [START_REF] Tomita | Train Running Test Transmitted by Superconducting Feeder Cable and Study as an Example of Line in Japan and France[END_REF].

An electrical model such as [START_REF] Venuturumilli | DC Line to Line Short-Circuit Fault Management in a Turbo-Electric Aircraft Propulsion System Using Superconducting Devices[END_REF] coupled with a thermal node model such as [START_REF] De Sousa | Thermal-electrical analogy for simulations of superconducting fault current limiters[END_REF], [START_REF] Rostami | Lumped-Parameter Thermal Model for Axial Flux Permanent Magnet Machines[END_REF] were used to study the temperature of the different layers of superconducting tapes as well as in LN2. The thermal model developed is only radial and does not consider the heat exchange in the longitudinal direction. In order to prevent any issue, the initial temperature used to calculate the transient behavior of the cable in case of a fault is the maximal temperature observed along its length in normal operation.

Fig. 5 shows simplified diagrams of the behavior of a superconducting cable in case of a fault with cooling based on a concentric pipe: (a) without polyamide layer, (b) with polyamide layer. When a fault occurs, the current starts to penetrate the copper layer and the temperature of the tapes rises rapidly and reaches about 10 K in a few milliseconds. It may change the LN2 to a gaseous state. The presence of the latter decreases the heat exchange in the cable and in some cases may also cause a dielectric breakdown of the cable. For this reason, a new layer is necessary to decrease the temperature gradient between the nitrogen and the superconducting tape in case of a fault. Therefore, to limit the temperature rise of the liquid nitrogen during a fault, and to avoid the risk of gas bubble formation, a thin layer of polyamide of thickness thpol has been added on the outer layer of the tapes, in direct contact with the liquid nitrogen. During the sizing process in case of a fault, the maximal temperature allowed for LN2 is 78 K, which is 10 K below the boiling point at 3 bar. The thickness of this polyamide layer must be designed according to the characteristics of the fault, the length of the cable and the capabilities of the cooling station. By varying thpol, the temperature difference between the dissipating parts and the liquid nitrogen during a fault can be adjusted. However, this thickness cannot be increased indefinitely, as this may greatly increase the recovery time tr after the fault is isolated [START_REF] Rubeli | Heat transfer monitoring between quenched high-temperature superconducting coated conductors and liquid nitrogen[END_REF].

C. Hydraulic and thermal design (normal operation)

The main parameter concerning the thermal cooling of the cable is the LN2 flow rate m  . The mass flow rate, in addition to being limited by the capacity of the station, is constrained by pressure drops p occurring in the pipe. Indeed, the circulation of a fluid in a long pipe induces strong pressure drops that can bring the LN2 below the minimum pressure to maintain its liquid state and decrease both cooling and dielectric performances [START_REF]NEXANS. Superconducting cable systems[END_REF]. The main calculations are made using Bernoulli's theorem applied to each pipe. The pressure drops in the pipes are obtained by considering regular pressure drops [START_REF] De Sousa | Investigation of a Concentric Three-Phase HTS Cable Connected to an SFCL Device[END_REF] and using the Blasius correlation in order to estimate the coefficient of friction [START_REF] Trinh | On the Blasius correlation for friction factors[END_REF].

In this section, the temperature of the tapes is calculated in the steady state along the cable length. For this thermal design, it is assumed that the only losses in the system are those introduced by the cryogenic lines and that they are proportional to the outer surface of the line. It is also assumed that the LN2 temperature in a single pipe only varies with the length of the cable while the heat transfer between the layers is only in the radial direction. As illustrated in Fig. 6, a power balance is performed between z and z+dz, with dz an infinitesimal length. The temperature of LN2 of each pipe along the length of the cable is then obtained by integration.

D. Losses of a DC HTS cable installation

In this section, the losses related to the superconducting cable and the losses related to the auxiliary components necessary for the operation of the entire cable are estimated. The architecture of the whole system is presented in Fig. 4. The losses of DC superconducting cables are mainly hydraulic losses and cryostat losses. At some junctions, the losses are mainly current-dependent; these are the losses related to the contact resistance. The values of contact resistances used in the design are of 200 and 800 nΩ.cm -2 for HTS tape to tape contact and HTS tape to copper contact, respectively [START_REF] Bagrets | Investigation of ReBCO Conductor Tape Joints for Superconducting Applications[END_REF]. The number of junctions has been chosen according to the length and radius of the cable and the dimensions of reel used to transport the cable to the installation area. The reel considered in our design has an outer diameter of 4.5 m, an inner diameter of 2.5 m and a width of 0.5 m.

A DC HTS cable requires two terminations making the connection with the conventional network at ambient temperature. For the calculation of termination losses, two categories are considered, heat losses and current-dependent losses. Heat losses are radiation losses and heat conduction losses, due to the temperature gradient at the ends of the current leads. Here, an ideal ratio between the length and cross section of the current lead has been chosen in order to obtain an equality between the joule losses and the conduction losses, i.e. 70 W/kA for 1 m of termination length.

III. RESULTS

The methods and models developed in the previous sections were used to size three DC superconducting cables. The characteristics of the studied cases are presented in Table I, where Pn is the nominal power of each cable. In this section, the design of the calculated cables is first shown, and the behavior of the cable in case of a fault will then be detailed. Finally, the best type of cooling is discussed as a function of the cable length and other results are discussed such as the losses and the necessary amount of liquid nitrogen.

A. Design of DC HTS cable

For the three DC HTS cables shown in Table I, Fig. 7 shows the evolution of the number of tapes N and the inner wall diameter di of the cables as a function of the number of layers per pole l. When the number of layers per pole l is increased from one to two, the inner diameter di of the cable decreases sharply, by about 30 %. On the other hand, the total number of tapes Nt for 10, 20 and 30 MW cables are respectively 72, 142 and 208 for one layer and 92, 164 and 248 for two layers. Obviously, the number of necessary HTS tapes increases with the number of layers. This is mainly due to the increase in the perpendicular component of the magnetic field applied to the HTS tapes. This is why the calculation code developed in the electromagnetic sizing considers the variation in the number of tapes per layer in order to obtain the ideal number of tapes per pole as a function of the transport current. We can therefore conclude that there is a compromise to be found in the number of layers per pole in order to reduce both the outer diameter of the cable and the total number of necessary tapes. The major parameters for three DC HTS cables 500 m long after the sizing process are summarized in Table II. The black symbols in Fig. 7 also correspond to the final design of cables A, B and C for 500 m.

B. Copper thickness design (in case of a fault)

During a fault, the current flows inside the copper layer from the HTS tapes leave the superconducting state at the very beginning. In this part, the behavior of Cable A -500 m has been studied in a short circuit for different thicknesses of the copper layer thCu. The appropriate choice of thCu mainly depends on the cable length and the protection devices of the network. In the framework of our study, typical Circuit Breakers (CB) in the SNCF network of 25 kA at peak and between 40 and 100 ms tripping time are used. This means that the maximal current during the fault Imax_Cu must be less than If = 25 kA. As mentioned before, the maximal temperature of the LN2 in contact with the dissipating parts of the cable during the fault must also be less than 78 K in order to avoid bubbles in LN2 and a dielectric breakdown in the cable. The behavior of the fault current during a short circuit for different copper thicknesses is shown in Fig. 8. In addition, Fig. 9 shows that it is very important to consider the variation in the electrical parameters of the cable as a function of temperature, as it varies a lot. Indeed, the temperature of the copper reaches more than 100 K in 40 ms. It can also be seen in Fig. 8 that the thinner the copper, the lower the peak of the fault current. This peak current is 17 kA, 13 kA, 10 kA, 7.5 kA, 6 kA for 300 μm, 200 μm, 150 μm, 100 μm, and 50 μm of copper, respectively. For each case, a polyamide layer about 300 μm thick ensures that TLN2_f stays below 78 K. In case of a fault, it can be seen in Fig. 9 that a maximal copper temperature of 123 K is reached before the circuit break for a copper thickness of 50 μm. The recovery time tr is the necessary time for the cable to recover the initial temperature after isolating the fault. tr is 58 s, 49 s, 44 s, 38 s, 33 s for 300 μm, 200 μm, 150 μm, 100 μm, and 50 μm, respectively. Obviously, reducing the copper thickness also decrease the recovery time, which is also beneficial for the operation of DC HTS cable system.

Table III shows the set of parameters obtained after sizing Cable B -500 m with three different tripping times tf of 40, 70 and 100 ms and for the same peak of current during the fault equal to the current of the circuit breaker, i.e. If = 25 kA. The maximal temperature in the dissipative parts of the cable Tmax_Cu is equal to 115, 127 and 136 K for tf is equal to 40, 70 and 100 ms respectively. Indeed, this rise in temperature requires a thicker polyamide layer in order to maintain the nitrogen in the liquid state, which has an impact on the recovery time, i.e. tr, respectively 53, 74 and 92 s for tf of 40, 70 and 100 ms.

From our experience, the typical polyamide thickness thpol is in the range of 200 to 800 μm. It mainly depends on the tripping time of the circuit breaker tf, but a compromise must therefore be found in the thickness of the copper and the thickness of the polyamide layer to both limit the fault current and reduce tr in order to meet the criteria of the rail network protection devices.

C. Hydraulic and thermal design (normal operation)

As an example, Fig. 10 shows the temperature distribution over the length of the cable B -1.5 km in the steady state for different types of cooling. The selection of the appropriate cooling system can easily be made by considering the cost of the required pump, based on the necessary mass m  and the pressure drop Δp. From a thermal point of view, it can be noted that the configuration of the concentric pipes (CP) requires a much lower cooling capacity since the difference between inlet and outlet temperature ΔTLN2 that the station has to cool down is much smaller than with separated pipes (SP), e.g. a ΔTLN2 of about 2.5 K is observed for CP and 9 K for SP. This is simply explained by the presence of two different cryostats for the separated pipes, which implies a larger external surface area, consequently generating more losses. Tmax_t is the maximal temperature in contact with the HTS tapes that has been used to design the current capacities of the cable in the algorithm shown in Fig. 1. Thus, it should be noted that in order to maintain the same maximal temperature Tmax_t, CP requires more powerful nitrogen circulation pumps than SP and CPSR. The interest of the CPSR and SP configurations compared to CP is that the hot point of the nitrogen Tmax_LN2 is not in contact with the HTS tapes, whereas in the CP configuration, Tmax_t and Tmax_LN2 are the same. In addition, the location of Tmax_t is difficult to control for CP, as it cannot be measured directly from the cable ends.

Fig. 11 and Fig. 12 show the evolution of the mass flow rate and pressure drop vs the length of Cable C for the three different configurations of cooling. It should be mentioned that the inner pipe diameter is 32 mm and the diameter of the outer pipe has been chosen to obtain the same hydraulic diameter as the inner pipe, i.e. 100 mm.

The length of the cable has a significant influence on the best choice for the type of cooling. Indeed, for a length of 1 km, the necessary flow rate for CP is 0.6 kg/s with a pressure drop of about 1.5 bar, and it increases up to 1.35 kg/s generating a pressure drop of 8.2 bar for a 2 km length cable. The CP architecture therefore allows low heat losses for short lengths, but it is not suitable for long lengths, as this type of cooling requires an increase in the mass flow rate, which cannot be increased indefinitely as it risks leading to a sharp increase in friction inside the pipes. It can also be seen that CPSR and SP require approximately the same flow rate to cool the cable. However, Fig. 12 shows that CPSR generates more pressure drop than SP, which is due to the fluid contact surface of the CPSR being larger than SP, generating more friction.

We would like to mention that the SP cooling was excluded from our cable selection despite its cooling efficiency and negligible pressure drop. Indeed, with SP, the cable is only cooled through the inner pipe, Fig. 1, which means that the recovery time after a fault might be very high, in particular for long length cables.

The CPSR ensures a low mass flow rate even for long lengths, i.e. a mass flow rate of 0.54 kg/s and a pressure drop of less than 7.02 bar for a length of 2 km. Although the CPSR requires the addition of a second external line for nitrogen return, this architecture is best suited to long cable lengths. Table IV presents the thermal and hydraulic parameters of the three cables in normal operation. The length of the cables has been chosen to present the most relevant results and variations: Cable A -500 m, Cable B -1000 m, and Cable C -2000 m.

D. DC HTS system losses

In order to size the three superconducting cables shown in Table IV, the losses were calculated in each case, and summarized in Table V. The consumption of liquid nitrogen and the power required for the circulation pumps are also mentioned. The role of the latter is to compensate for the losses of the installation. Of course, the greater the length or the current of the cable, the more the installation requires cooling power. That is, a power of about 3.5 kW for Cable A, 6.5 kW and 11 kW for Cables B and C respectively. It is also advisable to install two pumps in parallel to ensure the continuity of service of the entire system [START_REF] Yumura | Update of YOKOHAMA HTS Cable Project[END_REF]- [START_REF] Zong | Development of 35 kV 2000 A CD HTS Cable Demonstration Project[END_REF]. In the case of Cable C, three pumps are required, two of them running in parallel during normal operation while the third one ensures continuity of service. The sizing of a subcooler is relatively complex and requires a dedicated study by refrigeration experts. This study has not been carried out here but it can be mentioned that an electrically and thermally 4 Ptot are the total losses of the superconducting installation. QLN2 is the quantity of LN2 consumed. Np is the necessary number of circulation pumps. One circulation pump is always added for the continuity of service in case of failure of the operational pump-s). Pp is the power of a single pump.

reliable subcooler usually has three vacuum pumps, two operating at half their rated power and the third pump operating only when one pump is being serviced. The consumption of liquid nitrogen is related to total losses, including tank losses. This consumption is used to determine the volume of the required liquid nitrogen tank. The amount of nitrogen in the tank must not exceed 85 % of its total volume to maintain the nitrogen under pressure, and less than 45 % to ensure continuity in case of a filling incident or delay. The time between two fillings tfill can be determined from these constraints.

IV. CONCLUSION

This article shows a method for sizing superconducting cables as well as the various auxiliary components in a DC superconducting installation. Multi-physical analytical models were developed in order to guarantee an approach that meets the criteria of the French railway network.

This strategy includes an electromagnetic sizing for the determination of the critical current, associated with a hydraulic and thermal dimensioning in normal operation to determine the best type of cable cooling. The proposed sizing process also protects the HTS cable in case of a fault. A solution is proposed consisting in finding a compromise between the thickness of the copper layer to support a flow of a given fault current (related to the circuit breaker) and maintain the nitrogen in its liquid state. A solution which consists in increasing the number of layers per pole is also studied here in order to reduce the outer radius of the cable. Nevertheless, this strategy reduces the critical current of the tapes due to a higher applied magnetic field on the HTS tapes.

The increase in cable length requires higher mass flow rates, which leads to bigger cooling stations and increasingly powerful pumps. The performance of our code does not stop at the dimensioning of the cable; it allows the calculation of the diameter of cryogenic pipes in accordance with DIN EN 10380. In other words, the sizing of DC HTS cables including the sizing of nitrogen pipes, nitrogen tanks and circulation pumps already exists on the European market.

  1 (b) and (c), or inside the cable (a). The algorithm used for the design of DC superconducting cables is proposed in Fig. 3. The input parameters are Un and In, which are the operating voltage and current of the railway network respectively, If is the peak current that the Circuit Breaker (CB) has to cut off, tf is the duration before the CB opens, and L is the length of the desired cable. DIN EN10380 is the international standard specifying the minimum requirements for the design, manufacture, testing and installation of corrugated flexible metal pipes and hoses. In this paper, the following parameters have been used: Un = 1500 V, In = 6.67, 13.33 and 20 kA, If = 25 kA, tf = 50 ms and L are between 500 m and 2000 m.

Fig. 1 .

 1 Fig. 1. Representation of cooling configurations: (a) Concentric Pipes (CP), (b) Separated Pipes (SP), and (c) Concentric Pipes with Separated Return (CPSR).

Fig. 2 .

 2 Fig. 2. Complete view of a superconducting coaxial cable with its different layers.

Fig. 3 .

 3 Fig.3. The algorithm used for the design of DC superconducting cables: The electrical parameters of the railway network Un and In are the operating voltage and current respectively, and L is the length of the cable, Ic is the critical current of the cable, plcryo and plmax_cryo are respectively the cryostat losses and the maximum admissible cryostat losses per unit length, ICu is the current in the copper parts during a fault. TLN2_f is the temperature of LN2 in contact with the dissipating parts during a fault, ̇ is the mass flow of liquid nitrogen. Other parameters will be explained in the following sections.

Fig. 4 .

 4 Fig. 4. Typical diagram of the introduction of a superconducting cable into the railway network and location of a fault.

Fig. 5 .

 5 Fig. 5. Simplified diagrams of the behavior of a superconducting cable in case of a fault with cooling based on a concentric pipe: (a) without polyamide layer, (b) with polyamide layer.

Fig. 6 .

 6 Fig. 6. Simplified sketch of the architecture of concentric pipes. To(z) is the temperature in the outlet pipe and Ti(z) the temperature in the inlet pipe. ϕcyro is the heat flow from the cryostat and ϕo_i is the heat flow transferred from the outlet pipe to the inlet pipe.

Fig. 7 .

 7 Fig. 7. Evolution of the number of tapes N and the inner wall diameter di of the cables as a function of the number of layers per pole l. Nt is the total number of tapes and NPole(+) is the number of tapes for the "Positive pole" only.

Fig. 8 .

 8 Fig. 8. Behavior of the fault current of Cable A -500 m during a short circuit for different thicknesses of copper thCu.

Fig. 9 .

 9 Fig. 9. Evolution of the temperature of the tapes of Cable A -500 m before and after isolating the fault for different thicknesses of copper thCu.

Fig. 10 .

 10 Fig. 10. Temperature distribution along the length of Cable B -1.5 km. The mass flow rate requirements are 1 kg/s for CP and 0.4 kg/s for SP and CPSR. Tmax_LN2 is the maximal temperature of the LN2 of the outlet and Tmax_t is the maximal temperature of the liquid nitrogen along the cable in contact with the HTS tapes.

Fig. 11 .

 11 Fig. 11. Mass flow vs length of the Cable C for the three types of cooling CP, SP and CPSR in order to maintain Tmax_t = 73 K and Tmax_LN2 below 78 K with an inlet pressure of 15 bar.

Fig. 12 .

 12 Fig. 12. Pressure drop vs length of the Cable C for the three types of cooling CP, SP and CPSR in order to maintain Tmax_t = 73 K and Tmax_LN2 below 78 K with an inlet pressure of 15 bar.

TABLE I PARAMETERS

 I OF THE DC HTS CABLES TO BE STUDIED

	Parameter	Unit	Cable A	Cable B	Cable C
	Pn	MW	10	20	30
	Un	kV	1.5	1.5	1.5
	In	kA	6.67	13.33	20

TABLE III SET

 III OF PARAMETERS OBTAINED FOR CABLE B  500 M AFTER SIZING PRO-CESS FOR DIFFERENT TRIPPING TIMES

	Parameter	Unit	CB1	CB2	CB3
	tf	ms	40	70	100
	Imax_Cu = If	kA	25	25	25
	thCu	μm	150	150	150
	thpol	μm	310	430	550
	Tmax_Cu	K	115	127	136
	tr	s	53	74	92

TABLE IV THERMAL

 IV AND HYDRAULIC PARAMETERS IN NORMAL OPERATION

	Parameter	Unit	Cable A -500 m	Cable B -1000 m	Cable C -2000 m
	Type of cooling		CP	CP	CPSR
	̇	kg/s	0.254	0.595	0.536
	Δp	bar	0.192	1.267	7.019
			TABLE V
	LOSSES OF THE INSTALLATION AND CHARACTERISTICS OF THE COOLING SYS-
		TEM OF THE THREE CABLES
			Losses
	Parameter	Unit	Cable A -500 m	Cable B -1000 m	Cable C -2000 m
	Phyd	W	7	93	448
	Pcryo	W	746	1 524	3 173
	Pc_r	W	636	754	1 146
	Pter	W	2 104	3 840	5 380
	Ptot	W	3 493	6 211	10 147
			LN2
	QLN2	L/h	114.95	201.36	320.55
	Np		2	2	3
	Pp	W	3 500	6 500	5 500
			Tank
	Volume	L	61.62	80.36	80.36
	Height	m	14.15	18.05	18.05
	Diameter	m	3	3	3
	Losses	%	0.21	0.21	0.21
	tfill	day	7	6


Catherine Rebufa
email: c.rebufa@univ-amu.fr

Christian Pinatel

Jacques Artaud

Fabien Girard

Catherine Rébufa

A comparative study of the main international extra virgin olive oil competitions: Their impact on producers and consumers

Keywords:

niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

Olive oil occupies a special place in the Mediterranean subconscious, being associated with mythologies, legends and symbols and mentioned in the texts of monotheistic religions around the Mediterranean [START_REF] Meneley | Oleo-signs and quali-signs: The qualities of olive oil[END_REF][START_REF] Florentino | L'olivier dans le bon sens[END_REF]. It has become one of the most regulated and controlled agricultural products in response to the fraudulent practices existing since ancient times [START_REF] Aued-Pimentel | Fraud in olive oils of Brazilian market: Evaluation by fatty acid profile, difference of ECN 42 and quality parameters[END_REF][START_REF] Bimbo | An empirical framework to study food labelling fraud: An application to the Italian extra-virgin olive oil market[END_REF][START_REF] Cugat | Official quality controls and the fight against fraud in the olive oil sector in Catalonia. Results 2011-2014[END_REF][START_REF] Rossini | Mémoires de l'olivier[END_REF]. Olive oil is subject to continually evolving international standards and regulations that define the physico-chemical and organoleptic characteristics of different categories of virgin olive oils: extra virgin (EVOO), virgin (VOO), ordinary virgin olive oil (OVOO) and lampante (LOO) olive oils. These categories, defined by the International Olive Council (International Olive Oil Council (IOC), 2018), have been widely adopted by European regulation n • 2568/91 on organoleptic properties, except for ordinary virgin oil (Commission Regulation (EEC), 2016). Olive oil is currently the only agri-food product that has to be organoleptically analyzed in order to benefit from extra virgin and virgin designations. Under IOC regulations, evaluation by skilled tasters is based on the absence (extra virgin) or the weak presence (virgin) of defects and on three positive attributes: fruitiness, bitterness, and pungency.

However, placing an olive oil in a given category does not fully define the oil's organoleptic characteristics. Each category (extra virgin and virgin) covers a wide variety of oils not only in terms of the intensity of their positive attributes but also in terms of their type of fruitiness. Two main types of fruitiness are defined: green or ripe, and their intensity is broken down into delicate, medium, or robust. Olive oil competitions have adapted the terms they use to reflect the changes recommended by the IOC and the European regulations, replacing "intense "and "light" by robust and delicate respectively, as found on the labelling of olive oil bottles (International Olive Oil Council (IOC), 2018;Commission Regulation (EEC), 2016). Very often, in addition to the regulations, tasters employ an analogical description to evaluate the sensory descriptors of oils. Thus, both ortho-and retro-nasal olfactory perception are used to award scores on aromatic notes and aroma based on descriptors like artichoke, almond, banana, apple, tomato, allowing finer definition of monovarietal oils, olive oils with designation of origin, and the particularity of terroirs. Finally, to differentiate top quality EVOOs from standard ones, in some profile sheets, two additional aroma attributes are often considered: harmony and persistence [START_REF] Bongartz | Sensory evaluation of extra virgin olive oil (EVOO) extended to include the quality factor "Harmony[END_REF][START_REF] Bongartz | Evaluation of the "harmony value[END_REF][START_REF] Oberg | Evaluation of the "harmony/balance value" on the development of the sensorial quality of EVOO experiences in Germany and Europe[END_REF].

Under international standards and regulations, some producers add value to their olive oils through appellations such as Registered Designation of Origin (RDO), Protected Designation of Origin (PDO) and Protected Geographical Indication (PGI). These indicate that the oils possess a certain typicity (specific organoleptic profile in relation with a terroir) and originality, conferred by certain varieties of olive trees, a terroir, and know-how. Olive oil arouses a desire to seek maximum gastronomic value, especially from informed consumers. To satisfy this demand, the olive sector holds regional, national, or international competitions that select the best oils from organoleptic analyses, substantially adding to their commercial value [START_REF] Ballco | Do market prices correspond with consumer demands? Combining market valuation and consumer utility for extra virgin olive oil quality attributes in a traditional producing country[END_REF]. On the basis of rules specific to each competition, judges trained in olive oil tasting award prizes to oils with the aim of providing recognition of producers' work, guiding consumers and leading them to experience the diversity of olive oil tastes. These awards can impact both consumer awareness of high-quality products and the entire olive sector: agricultural production, processing, packaging, logistics, distribution, and suppliers. Competition regulations for selecting samples are often similar of those of International Oil Competition Mario Solinas (IOC Mario Solinas, 2019): (i) some authorize only oils with denomination of origin and group them according to this criterion; (ii) others require that the extra virgin olive oils presented be accompanied by a panel test certificate from a laboratory accredited by the International Oil Council (IOC) and European Union (EU) regulations; (iii) others let the producer decide which category to compete in (self-assessment of fruitiness, bitterness, and pungency intensities). Finally, outside the competitions, guides such as EVOOLEUM, Flos olei, GastrOleum, and Iber Oleum list oils from all sources without distinction, as classified by international tasters according to their organoleptic properties with reference to pre-established criteria. Like the competitions, these guides serve to add value to olive oils and inform consumers.

In the case of competitions rewarding oils with a denomination of origin, the panel of judges seeks conformity of typicity of the origin (PDO) and selects the most representative ones [START_REF] Vichi | Catalan virgin olive oil protected designations of origin: Physicochemical and major sensory attributes[END_REF]. Otherwise, the oils are systematically classified according to type of fruitiness (green or ripe). However, to ensure fairness, subclasses related to the intensity of fruitiness are introduced (robust, medium, and delicate) because it is impossible to objectively compare a delicate ripe fruitiness with a robust green fruitiness. This categorization is either provided by the producer or performed in advance following sample tasting by the competition organizers.

This paper compares how different international competitions select eligible olive oils, analyzing their sensory assessment sheets to determine the diversity and weight of the parameters considered. We present an overview of the different awards and the modes of announcing results, together with the special case of guides. We also present an analysis of various studies on consumer preferences, seeking to determine whether consumers are impacted by these awards, and whether their preferences reflect the selection criteria of expert panels.

An overview of olive oil competitions

Like most agri-food products, virgin olive oils are the subject of various competitions: international, national, regional, departmental, and sometimes even cantonal. We examined as many as possible of the numerous olive oil competitions: their similarities and differences, the different stakeholders (oil producers, organizers, and judges), and the awards' impact on consumers. Each competition uses a different award system, and the percentage of olive oils awarded prizes can vary from one competition to another. Producers have to comply with sample selection criteria that differ depending on the competition and pay more or less expensive entry fees. Competition organization also differs greatly in the financial and communications means they devote to raising awareness of their competition and of the winning olive oils. Moreover, judges apply sensory evaluation criteria whose weights differ depending on the competition. In addition to the competitions, specialist guides provide further information on olive oils and their production.

Aims of competitions

Olive oil producers enter competitions to promote their image. The competitions are a useful marketing tool, rewarding the best producers while offering support to non-winners. Awards also serve as a guide, informing the consumer about olive oils of high quality. They aim to promote the diversity of virgin olive oils so as to raise awareness of their sensory differences. Often, requirements arising from the European Union agricultural policy promoting olive oil quality and enhancing sector competitiveness have to be taken into account [START_REF] Chousou | A retrospective view of the EU policy reforms in the olive oil sector and future perspectives[END_REF]. This policy has very special connotations for certain countries such as Italy and Spain, which have chosen to integrate the promotion of regional produce into the overall development of the production system. These countries promote specific territorial resources as part of a package including nature conservation, tourism, and education [START_REF] Polenzani | Sustainability perception of local extra virgin olive oil and consumers' attitude: A new Italian perspective[END_REF]. As in Greece, olive oil enjoys a high profile in the food industry and is of great importance to the economic and social life of the country.

Identification of competitions

The various competitions (Table 1) were identified via website listings such as those of OléOMONDO (an e-commerce retailer selling "Grands Crus" organic olive oil developed by committed producers, all recipients of awards from the most prestigious international competitions), FRANCE OLIVE-AFIDOL (French Interprofessional Olive Association) and EVOO World Ranking. The regulations for olive oil competitions are generally available on-line in varying degrees of detail, explaining to consumers how selection is handled.

Eligible olive oil samples

Most competitions are open to all olive-oil producing countries, from both the northern and southern hemispheres, provided their oils are extra virgin olive oils. Flavored and infused olive oils are also eligible to participate in some (Athena International Olive Oil competition (ATHIOOC), EVO International Olive Oil competition (EVO IOOC), Los Angeles International Extra Virgin Oil competition (Los Angeles)), while others are open exclusively to organic extra virgin olive oil, certified under EU regulations and/or under the U.S. National Organic Program (NOP), or the Japanese Standard for Organic Agricultural Processed Food (JAS).

All submitted samples must contain olive oil produced in the crop year of the competition and must be submitted in their normal retail packaging when sampling is not directly done from the tanks in the presence of a notary. Olive oil samples must bear an official brand label compliant with the laws of the country of origin or the country they were bottled in. Often, organizers require a recent chemical analyses certificate from an accredited testing laboratory, indicating basic physicochemical properties (International Olive Oil Council (IOC), 2018; Commission Regulation (EEC) 2568/91, 2016) and submitted with the entry form for each sample. Moreover, some competitions, particularly the IOC Mario Solinas and EVO IOOC, ask for a certificate of sensory analysis delivered by a tasting panel holding IOC recognition to prove an oil's extra virgin category. However, [START_REF] Circi | Panel test and chemical analyses of commercial olive oils: A comparative study[END_REF] indicated that the organoleptic evaluations of certain EVOOs by nine approved labs were not consistent. The panel test used to assign a sample to its correct category, virgin or extra virgin, is not foolproof [START_REF] Albi | Study of the precision of an analytical taste panel for sensory evaluation of virgin olive oil. Establishment of criteria for the elimination of abnormal results[END_REF], and this has been known to penalize some oils. Heated debates and controversies surround the sensory evaluation of the same EVOOs by different testing laboratories and panels of experts, over either an absence of sensory defects in EVOOs or very slight sensory defects only perceived by certain tasters [START_REF] Circi | Panel test and chemical analyses of commercial olive oils: A comparative study[END_REF]. A strategy for avoiding disagreements when divergent results are provided by different sensory testing laboratories (sometimes non-accredited) was proposed by [START_REF] Aparicio-Ruiz | Does authenticity of virgin olive oil sensory quality require input from chemistry[END_REF], using reference materials such as volatiles and sensory descriptors to enhance taster training. Other authors [START_REF] Barbieri | Alignment and proficiency of virgin olive oil sensory panels: The OLEUM approach[END_REF] also addressed the issue of monitoring and improving the performance of sensory panels by using a "decision tree", which involved agreeing on a category or a main perceived defect and/or fruitiness attribute; in addition, these authors recommended quality control tools. Their method led to satisfactory classification for 289 out of 334 tested EVOOs, while a formative reassessment enabled 41 out of 45 initially discarded samples to be classified. In addition, chemometric approaches based on sensorial data and chemical measurements were used to discriminate between EVOOs and VOOs or to determine their origins, most being recognized as difficult to accurately classify by the panel test [START_REF] Cecchi | Headspace solid-phase Microextraction-Gas Chromatography-mass spectrometry quantification of the volatile profile of more than 1200 virgin olive oils for supporting the panel test in their classification: Comparison of different chemometric approaches[END_REF][START_REF] Cecchi | Authentication of the geographical origin of virgin olive oils from the main worldwide producing countries: A new combination of HS-SPME-GC-MS analysis of volatile compounds and chemometrics applied to 1217 samples[END_REF].

Besides these chemical and sensory characterizations, some competitions request supplementary information like the quantity of olive oil produced in the last crop, the average annual quantity produced over the last 4 years, the average age of olive trees, the type of olive grove (traditional or intensive), the collection system (manual, mechanical), the extraction system and temperatures, even including the manufacturer of the extraction system. Generally, competitions are open to all individual producers, olive oil mills, producer cooperatives and cooperative associations, bottlers, exporting companies, and any business that produces, bottles, and trades in branded extra virgin olive oils. Proof of provenance of all the samples must be guaranteed, on request of the organizing committee, with appropriate documentation.

Competition locations and fees

Competitions take place in the major oil-producing countries such as Spain, Italy, Greece, and Portugal; France organizes two international competitions yearly (Agence pour la Valorisation des Produits Agricoles (AVPA) and Les Olivalies). The largest numbers of olive oil samples are presented in countries with low production such as China, Japan, and the United States of America (USA), or in countries known as large importers such as Germany, England, and Switzerland (IndexMundi, 2019).

In the most prestigious competitions, many countries are represented and as many as 1000 olive oil samples may be presented (New York International Olive Oil Competition, NYIOOC). Judging brings together numerous foreign experts of international renown for several days of tasting, with registration fees ranging from 50 to 460 euros according to EVOO: extra virgin olive oil, IOOC: international olive oil competition.

the reputation of the competition. Lower fees are offered if more than one sample is presented and the registration fees per sample can also be reduced for "early bird" payment. Generally, fees cover the following: (i) sensory evaluation by the tasters, (ii) organization of the awards ceremony, (iii) publication of results in the daily press, specialist magazines and on Internet, (iv) certificates and trophy if applicable.

Selection of judges

Assessing large numbers of olive oil samples is very expensive, due to the need for an expert tasting panel. There are no official regulations for the selection of judges, who are chosen by the competition organizers. Some require jury leaders, approved by the IOC; others build their juries from experts recognized as trained in oil-tasting skills. Depending on the total number of samples to be evaluated, the team leader may divide the jury into subgroups and appoint one coordinator for each sub-group. A special case is OLIVINUS Children, one of the two competitions in the world judged by children between 8 and 15 years old, who designate the best EVOOs worldwide according to their preference. Sixty children compose this panel, which trains all year round. The section "Biol Kids" in the "Biol Prize" competition is the second case, where a special prize is awarded by a jury of children selected after a series of training sessions in local primary schools. Overall, there appears to be a certain diversity and heterogeneity in the selection of judges.

Olive oil selection

In some competitions, all oils compete without distinction as to their origin, while in others, categories of fruitiness are established, or selection is restricted to oils with a designation of origin and the categories are judged separately. Thus, some competitions are open to olive oils belonging to the following categories: (i) extra virgin olive oil, (ii) organic extra virgin olive oil, (iii) PDO/PGI extra virgin olive oil (Protected Designation of Origin and the Protected Geographical Indication), (iv) monovarietal extra virgin olive oil, (v) blended extra virgin olive oil. For other competitions, extra virgin olive oils are divided by intensity of fruitiness into: (i) delicate fruitiness, (ii) medium fruitiness, (iii) robust fruitiness. If types of fruitiness (ripe or green) are also distinguished, this yields six subcategories, the commonest approach. An exception is the AVPA competition, where no distinction as to fruitiness is made in the tasting and the six subcategories are used only to announce the results and situate the winning olive oils. Only one competition (London International Olive Oil Competition, London IOOC) addresses health, quantifying the content of the major phenols (oleocanthal, oleacein, oleuropein aglycon (monoaldehyde and dialdehyde forms) and ligstroside aglycon (monoaldehyde and dialdehyde forms)) via Nuclear Magnetic Resonance (NMR) spectroscopy [START_REF] Karkoula | Direct measurement of oleocanthal and oleacein levels in olive oil by quantitative 1 H NMR. Establishment of a new index for the characterization of extra virgin olive oils[END_REF][START_REF] Karkoula | Quantitative measurement of major secoiridoid derivatives in olive oil using qNMR. Proof of the artificial formation of aldehydic oleuropein and ligstroside aglycon isomers[END_REF] to verify the conformity of healthiness claims with EU Commission Regulation 432/2012. There is also a prize for "highest polyphenol content" awarded by the Japan Olive Oil Prize (JOOP) competition. These different types of selection ensure that competitions represent the diversity of olive oils. The mode of sample collection also varies in situ collection or dispatch by the candidate, involving several stages of compliance with competition selection regulations. Since the olive oil samples are tasted anonymously, they must be coded for blind examination; details of anonymity procedures are available from the organizers.

Selection policy

Since different juries score the oils, it is important to harmonize the scores so they can be compared objectively. However, no details on harmonization are communicated in the regulations of most competitions, except for AVPA, which evens out the scores of the different juries as well as scores at the different selection stages, using the mean and the standard deviation.

Although most often based on the Mario Solinas regulations, the different competitions have established their own sensory evaluation sheets, selecting the criteria that best reflect the objectives of their competition and the targeted olive oil categories: green or ripe fruitiness with a delicate, medium or robust intensity. Table 2 presents a comparative study of the sensory evaluation sheets of 10 international competitions and an international guide. The sensory evaluation method adopted by the majority reflects the tasting process. First, various defects (or negative attributes) are identified and then, positive attributes are quantified through (i) olfactory sensations focusing on harmony and fruitiness, (ii) gustatory-retronasal sensations, where bitterness and pungency are assessed in addition to fruitiness and harmony, and (iii) final gustatory-retronasal sensations enabling the taster to quantify the oil's complexity and its persistence in the mouth.

Often, olive oils are assessed using a scoring system with a maximum score of 100, and less frequently, with a decimal system ranging from 0 to 10.00 without a total score. Three profile sheets (ATHIOOC, EVO IOO and NYOOC) are clearly based on that of IOC Mario Solinas (IOC Mario Solinas, 2018). Some competitions and guides (Oil China IOOC, Leone d'Oro, and Los Angeles) do not take into account defects, some cite defects but do not name them explicitly (EVOOLEUM and SIAL), while others ask judges to state their perceptions of defects with or without numerical quantification. Generally, positive attributes are given scores out of 100, except in the Olive Oil Award Zurich (OOAZ), Japan Olive Oil Prize (JOOP) and SIAL Olive d'Or (SIAL) competitions, which require evaluation from 0 to 10. For the other six competitions and the EVOOLEUM guide, perception of positive attributes is divided into three sensations: (i) olfactory sensations, (ii) gustatory-retronasal sensations, (iii) final gustatory/retronasal sensations.

Positive and negative attributes contribute differently to the final score. Scores vary from 20 (Los Angeles) to 50 (EVOOLEUM) for olfactory sensations, from 35 (Leone d'Oro) to 50 (Oil China IOOC) for gustatory/retronasal sensations and from 10 (EVOOLEUM) to 35 (Los Angeles) for final gustatory/retronasal sensations. The attributes, bitter and pungent or spicy, are evaluated under gustatory/retronasal sensations for ATHIOOC, EVO IOOC, IOC Solinas and NYIOOC competitions, with scores between 0 and 3 (out of a total of 45 or 50), while the other competitions set a maximum of 10 points. To extend the sensory evaluation of olive oils, other descriptors are included such as complexity, persistence, harmony, and balance. At the end, some competitions require to detect some analogic descriptors (artichoke, apple, banana, tomato, among others) and to qualify or quantify fruitiness intensity (delicate, medium, robust). Thus, from one international competition to another, the principal attributes can be fruitiness, bitterness, pungency, and harmony. Certain competitions assess whether an olive oil is "balanced" (Leone d'Oro) or "unbalanced" (JOOP), instead of its harmony. Others ask judges to quantify the complexity of its fruitiness (JOOP, Leone d'Oro, Los Angeles). But their evaluation sheets contain too many additional attributes whose detection and evaluation can be difficult even for an expert taster.

French competitions AVPA and "Les Olivalies" were not included in these comparisons because their selection system is different. Little information is given on the regulations for "Les Olivalies", except for the sensory assessment, which is descriptive and includes scores on olfactory, gustatory, retronasal aspects and overall impression. The prizes are awarded exclusively and directly at the end of each sample tasting, on the basis of discussions among the tasters and taking the descriptors into account. Immediate judgements by the members of the jury in real time determine whether or not the sample deserves a prize, and which prize. As regards the sensory evaluation sheets presented above, AVPA uses a simpler procedure to assess the organoleptic properties of EVOOs. Olive oils are judged on five attributes: (i) and (ii) the intensities of bitterness and pungency, defined in IOC regulations (International Olive Oil Council (IOC), 2018) and each evaluated on a 0-10 scale, (iii) aromatic maturity, a specific descriptor representing the maturity of fruitiness (green or ripe) and which is rated on a continuous scale from 0% (green Olive fruitiness 0-7 0-7 0-7 0-7 5-10 0-30 0-10 X Other fruits 0-3 Olive fruitiness 0-10 0-10 0-10 0-10 5-10 0-20 0-10 0-10 0-10 0-10 Green 0-2 0-2 0-2 0-2 X Sweet 0-4 0-4 0-4 0-4 3-10 0-5 0-5 Other fruits X X Fruity green X X Fruity ripe X X X Bitter 0-3 0-3 0-3 0-3 0-10 0-10 0-10 X 0-10 Pungent 0-3 0-3 0-3 0-10 0-10 X 0-10 Spicy 0-3 0-10 Other Positive Sensations fruitiness) to 100% (ripe fruitiness), (iv) the intensity of fruitiness (0-10 scale) and (v) the harmony of fruitiness (0-10 scale). A supplementary parameter is considered, such as the intensity of any defects (only evaluated on a 0-10 scale). Then, four of these parameters are combined into two special descriptors. The first is the fruitiness note (N), obtained by combining the intensity of fruitiness (I) with the harmony of fruitiness (H) and the intensity of the maximum defect (D) according to the equation below (Eq. ( 1)), to which a score of 10 is added to obtain a total out of 20, easier for the producers to understand and avoiding negative ratings for oils with defects:

0-3 0-3 0-3 X X Green 0-2 0-2 0-2 0-2 X Other positive sensations 0-3 0-3 0-3 0-3 1-7 X Harmony 0-20 0-20 0-20 0-20
0-3 0-3 0-3 0-3 Harmony 0-20 0-20 0-20 0-20 5-10 X X 0-35 Persistence X X 0-5 Unbalanced X Intensity fruitiness X 0-20 Complexity fruitiness 0-10 X 0-10 0-25 Fluidity X X Equilibre 0-5 0-5 Analogic descriptors X X X X X X X X
N = (0.72 × I) + (0.28 × H) + 10 -D (1)
The second combination of parameters forms a special descriptor named structure (S), obtained by weighting the degree of intensity of bitterness (B) and the degree of intensity of pungency (P) to take into account consumer preferences according to the following equation (Eq. ( 2)):

S = (0.62 × B) + (0.38 × P) (2)
The aromatic maturity parameter remains untouched. This competition classifies oils differently, without total scores. A novel approach is proposed in which the scores for the three special descriptors (structure, aromatic maturity, and fruity note) are used to build a spatial representation of the different olive oils tasted, defining a 3D scatter plot with a barycentre around which the different oil samples are distributed. A fitting of a mathematical model (linear regression) on the 3D scatter plot makes it possible to obtain a classification of the samples taking into account the three special descriptors simultaneously, and therefore to select the oils during the different tasting rounds, aiming for an equitable distribution of the oils selected in all directions, i.e. from robust green to delicate ripe.

Der FEINSCHMECKER, Germany's leading leisure and lifestyle magazine for over forty years, has organized its own competition every year since 2003: the FEINSCHMECKER OLIO Award. Few details are available on its regulations, but several hundred oils (up to 500 from 11 different countries in 2019) are known to be tasted in a blind test by a top-class jury in several days. FEINSCHMECKER tasting follows the rules laid down by the International Olive Oil Council by dividing oils into groups: "slightly fruity", subtle in fragrance and with little bitterness, "medium-fruity" and "robustly fruity", very robust in bouquet, clearly bitter, with an extremely sharp aftertaste. Two criteria determine the classification of oils. The first is intensity of fragrance and taste, called fruitiness: with a maximum of 5 points for fruitiness intensity, an olive oil up to 3.0 has a slightly fruity (delicate) taste, from 3.0 to about 4.5 medium-fruity, and over 4.5 robustly fruity. The second criterion is intensity of bitterness: if the oil tastes mildly sweet and not bitter at all, it is classified in the slightly fruity category.

When design is judged in competitions (BIOL, EVOOLEUM, JOOP, Leone D'Oro, LIOOC, Los Angeles, SIAL, and TERRAOLIVO), a numerical rating is given on the label, the bottle, the cap, and the material used to package the oil. Particular attention is paid to the physical means (paper, inks, and typography), to the artwork or illustrations (packaging designed to appeal to a particular audience), to innovation (an original illustration can drive package design), to use of color (ordinary or striking), as well as to the general image of the product.

The different awards

The usual procedure is to award gold, silver, and bronze medals to the olive oil samples obtaining the highest scores (usually maximum 100 points) for each category. The percentage of medals awarded, when known, represents between 30 and 45% of the samples in a category. Sometimes, samples that obtain scores as high as 95.5 are distinguished by a particular prize, like "best in class", "platinum" or "double gold" (ATHIOOC). To further reward participants, the olive oil competitions award special prizes (Table 3). To encourage producers, a compensatory "special gourmet diploma" is awarded to finalist participants who did not receive a medal (AVPA). Since 2019, a special prize has been awarded to highlight the presence of a country of honor in the SIAL Canada competition.

Because packaging of food products influences consumers' sensory expectations and the perceived newness of the product [START_REF] Miltgen | Communicating sensory attributes and innovation through food product labeling[END_REF], design competitions attribute awards for label, bottle, innovation, and overall product image (BIOL, EVOOLEUM, JOOP, Leone D'Oro, LIOOC, Los Angeles, TERRAOLIVO and SIAL). Some organizing committees (LIOOC and Los Angeles) award prizes for design of organic extra virgin oils that uses environmentally friendly materials (special prize ecodesign) and reward environmental commitment efforts (special prize for sustainability). A prize may also be granted to the company producing the greatest volume. X: cited attributes but not quantified, in bracket: scores not totaled. encounters, competitions bring together consumers and producers during the final awards ceremony (ATHIOOC and JOOP). In certain cases, there is a full-day presentation of the award-winning olive oils, all available for tasting. Some competitions run seminars and workshops promoting the attendee companies (OOAZ). Others (Oil China IOOC) have specialized events like an edible oil forum, edible oil food matching or an edible oil marketing summit. Strategically, the SIAL competition chooses to realize olive oil selection and to present the winning oils in the showroom of the Canadian agrifood industry's national tradeshow, SIAL Canada, which brings together all the major industry players and more than 25,000 visitors from 60 different countries. Like them, the "BIOFACH Olive Oil Awards", which only examines high-quality organic olive oils in the context of external catering (from the canteen and commercial cuisine to the upscale restaurant), announces its winners on a stand at an international tradeshow. Olive Japan (JOOP) each year designates an "olive ambassador" (generally a public figure) to present the prizes during its awards ceremony. Results can be published in newspapers as well as promoted via news releases and broadcasting media announcements (via radio and television). On-line results are usually available on the competition website, with the opportunity to buy award-winning olive oils. Nevertheless, the scores obtained are rarely made public.

Announcement of results

In addition to broadening taste horizons and enriching human

The specific case of guides

Guides in both physical and digital version are also published in English or in the language of the country: EVOOLEUM, Flos Olei (duallanguage Italian-English and Italian-Chinese), Gastroleum, and IBER OLEUM. They give details of the management team, the members of the jury, and the prize-winning olive oils (photo of the bottle, its brand name, its score and medals or special awards obtained, its tasting and pairings).

Guides provide more information on EVOO production than can be obtained from competition results. Symbols are employed to indicate the country of origin, the Protected Designation of Origin or Protected Geographical Indication to which oils belong, the olive varieties from which they are obtained (with or without percentages), the packaging in which they are presented (glass or metal container). Other symbols indicate the volume of production, the olive harvesting method (handpicked or mechanical: beaters, trunk shakers, and vibrators), the altitude of the olive groves, sales contacts, the quantity to be sold, price range, export certificates, and the cultivation and plantation systems, as well as the oils certified as Kosher and Halal. A complete phenolic compound analysis realized by the University of Córdoba (total phenolic compound content and content in specific phenols such as hydroxytyrosol, tyrosol, oleuropein aglycone, and oleocanthal) of the 100 tested oils is included in the EVOOLEUM guide. This guide evaluates the organoleptic qualities of oils as required by IOC regulations, slightly modified so as to give equal weight to the fruitiness, potency, and complexity of oils on the nose and their harmony, sweetness, and balance on the palate. The arithmetic mean of the total scores of all jury members is calculated removing the highest and lowest values, thus resulting in a final score of 0-100 points. In the event of there being two or more oils obtaining the same total score to within two decimal places, they are ranked according to the Global Quality Index determined by analytics. The 100 oils obtaining the highest scores are included in the guide and presented in alphabetical order, featuring the score obtained. The first ten classified, EVOO TOP100, and the best oils in each category (eleven in total based on fruitiness, olive variety, country of production, and packaging design) receive a commemorative trophy at an awards ceremony organized in a European capital during a prestigious gastronomic event. The top 100 winners receive a diploma recording their score and two copies of the EVOOLEUM paper guide. Moreover, this guide is promoted at all forums, competitions, national and international fairs, in trade and gastronomic events where the olive oil sector has a special impact.

The Flos Olei guide takes a slightly different approach, spotlighting the contribution of a single farm and rewarding all aspects of the production process. Each country is presented in an introductory text containing historical and cultural information on olive varieties, olivegrowing areas, and production. Spain and Italy have their own section. A specific card describes each company, with tasting scores and gastronomic combinations. After their organoleptic examination, the tasting panel operates according to the IOC method in "open mode" by reporting their opinions to the panel coordinator, who fills in a specific sensory evaluation sheet. A numerical score (up to 100) is attributed to farms, ranking them on the basis of ownership of olive trees and an oil mill, extraction system, relationships between quality/price, quality/ quantity, and quality/packaging. The guide claims to be "geared towards trade professionals as well as foodies who want to learn more about the wonderful world of extra virgin olive oil" with supplementary "articles about the art of olive oil tasting, international olive-growing, an analysis of the global evolution of olive oil production, EVOO and gastronomy, the most stunning points of sale around the world, centuries-old olive trees, EVOO and health, an olive oil dictionary and others". A Smartphone application of Flos Olei guide is now available in three languages, Italian, English and Chinese.

In contrast to the Flos Olei guide's international approach, Iber Oleum restricts its selection of the best EVOOs to those of Spain. All the people and entitles who participate in the production and marketing of olive oils are represented (oil-producing companies, co-operatives, packaging manufacturers, exporters, restaurant owners, and all those involved in the olive sector). There is one condition: each oil sample must come from a minimum homogeneous batch of 3000 kg, either from conventional production or organic production, and oil samples must be collected by Iber Oleum technical staff. The oils presented in the 2020 guide are therefore classified in two categories: (i) robust fruitiness, (ii) delicate to medium fruitiness. As in the AVPA regulations, the two categories of oils are tasted during different sessions to guarantee a fair score and avoid the "contrast" effect that can occur between samples from different categories tasted at random. This guide offers more consumer-oriented advice, allowing anyone to choose, without fear of error, which oils they want to acquire, the sensations they want to experience, and/or the oils they require for different uses.

GastrOleum is a free application available in Spanish and English, offering a very large database of Spanish and international extra virgin olive oils, geo-located on an interactive map and harmonized according to their sensory profile. Their organoleptic characteristics can be tracked using a barcode. GastrOleum also includes a series of recipes and cooking techniques using excellent extra virgin oils; as well as restaurant names, tips, and tricks of the trade by prestigious chefs. It connects the world of extra virgin oil with gastronomy, through multimedia content: links, music, image gallery, audio, videos, and interactive elements, for a "good" user experience. The objective of GastrOleum, like other guides, is to teach users (chefs, hospitality professionals, and consumers, among others) how to use EVOOs in the kitchen so as to enjoy the full potential of this raw material. It also aims to publicly disseminate the EVOO culture through new technologies and to increase world demand through participatory conversations about its gastronomic uses. The samples are evaluated and defined according to their organoleptic parameters, classed according to a practical system based on the IOC method (International Olive Oil Council (IOC), 2018). To this end, the evaluation team perform sensory analysis defining the qualities of each sample, which is thus given a culinary classification A, B, or C (A: Aromatic; B: Balanced; C: Full-bodied) depending on its characteristics and recommended culinary uses. The organizers recommend that oils should be presented to GastrOleum on the date on which the producer obtains the fresh oil, as this is when the oil reaches its maximum expression. Nevertheless, all those interested can apply to GastrOleum when they deem it appropriate. The data listed by oil on the GastrOleum application are extensive and, like those provided by EVOOLEUM and Flos Olei guides, constitute excellent teaching tools for consumers and hospitality professionals around the world.

Inter-competition classification by EVOO World Ranking

The EVOO World Ranking website deserves mention for its initiative and the major contribution it makes in collecting the annual results of international competitions to classify award-winning olive oils. The website was set up a few years ago, based on the ranking system WRW & S (World Ranking Wine & Spirit) created in 1997 by the WAWWJ (World Association of Writers and Journalists of Wines and Spirits). Its aim is to promote the EVOOs participating in the 30 best-known international competitions during the year, except for classifications by books or magazines. This website lists the EVOOs that have won the most prizes worldwide, as well as the producers, the best oils by variety or type, and what area of the world they come from. Competitions are classed by continent and country, with the IOC Mario Solinas considered as reference. The rating system considers the competition's importance in the world, the number of samples, the number of participating countries, and its impact in the major olive oil consumption areas. First, the competition is attributed a score: 10 points for IOC Mario Solinas, the number one, and between 5 and 9 points for the remaining competitions. Then, a second score is attributed for each award, taking the awards from all competitions as equal. For each EVOO, the scores for competitions and awards are multiplied. The scores obtained by a given EVOO in all competitions are added up to obtain the total score for the year. Only EVOOs having accumulated more than 160 points are awarded a diploma and stickers (which can be printed out and used freely).

Disconnect between consumer preferences and expert evaluation

Competitions are a way to promote the winning producers to buyers, consumers, international markets, and through the various media. However, consumers have been found not to appreciate the same sensory characteristics as experts [START_REF] Delgado | How do consumer hedonic ratings for extra virgin olive oil relate to quality ratings by experts and descriptive analysis ratings?[END_REF], 2012;[START_REF] Delgado | Evaluating bottles and labels versus tasting the oils blind: Effects of packaging and labeling on consumer preferences, purchase intentions and expectations for extra virgin olive oil[END_REF][START_REF] Pagliuca | The olive oil sector: A comparison between consumers and "experts" choices by the sensory analysis[END_REF][START_REF] Valli | Sensory analysis and consumer acceptance of 140 high-quality extra virgin olive oils[END_REF][START_REF] Barbieri | Do consumers recognize the positive sensorial attributes of extra virgin olive oils related with their composition? A case study on conventional and organic products[END_REF][START_REF] Fernandes | Sensory evaluation of high-quality virgin olive oil: Panel analysis versus consumer perception[END_REF][START_REF] Cavallo | Extra-virgin olive oil: Are consumers provided with the sensory quality they want? A hedonic price model with sensory attributes[END_REF][START_REF] Cavallo | Consumers' perceptions and preferences for bitterness in vegetable foods: The case of extravirgin olive oil and brassicaceae -a narrative review[END_REF][START_REF] Caracciolo | Consumers (Dis)Preference for bitterness in extra virgin olive oil: A field experiment[END_REF]. A review [START_REF] Del Giudice | What attributes of extra virgin olive oil are really important for consumers: A meta-analysis of consumers' stated preferences?[END_REF] summarized the literature between 1994 and 2014 on consumer preferences relating to EVOO characteristics; the selected papers analyzed intrinsic (taste, appearance, and color) and extrinsic (packaging, certifications, label, brand, etc.) product attributes. In most cases, consumers were found not to appreciate the complex sensory profile of virgin olive oil, particularly its bitterness and pungency. The experts, on the other hand, associate these characteristics with the presence of healthy substances. Unlike the many untrained consumers, these experts are used to tasting this type of oil. This discrepancy between evaluations by experts and consumers could represent a serious limit to consumer demand for an olive oil with health benefits [START_REF] Cavallo | Extra-virgin olive oil: Are consumers provided with the sensory quality they want? A hedonic price model with sensory attributes[END_REF]. [START_REF] Cavallo | Consumers' perceptions and preferences for bitterness in vegetable foods: The case of extravirgin olive oil and brassicaceae -a narrative review[END_REF] revealed that although a bitter taste provoked aversion for a large number of consumers, this bitterness was sometimes promoted in innovative or organic products, or simply sought after in certain widely consumed foods such as coffee, chocolate, and alcoholic beverages. The econometric model proposed in the study of [START_REF] Caracciolo | Consumers (Dis)Preference for bitterness in extra virgin olive oil: A field experiment[END_REF] showed that the bitterness of EVOOs constituted a commercial disadvantage because consumers preferred EVOOs with a sweet sensory profile, unlike trained judges, for whom bitterness and pungency had a positive connotation. A preference mapping based on IOC expert panel and consumer preference data (blind session) [START_REF] Delgado | How do consumer hedonic ratings for extra virgin olive oil relate to quality ratings by experts and descriptive analysis ratings?[END_REF] showed that while consumers appreciated fruitiness and, to some extent, pungency, they preferred olive oils with limited bitterness and pungency, attributes linked to richness in phenolic compounds. Although they found that consumers learned to accept strong sensory features after personal experiences with local products, consumer expectations depended on their cultural, historic, and gastronomic practices. Moreover, Vázquez-Araújo et al. ( 2014) used a cross-cultural study to reveal clear differences between Spanish and US consumers. Spanish consumers preferred extra virgin olive oil characterized by bitter, pungent, and more green notes, while US consumers liked olive oils characterized by fruity, floral, and sweet notes. They concluded that if Spanish producers wanted to sell olive oils to US consumers, they had to adapt their olive oil production to the US consumer's expectations by offering oils with the right intensity of fruitiness notes but with limited bitterness or pungency.

These studies suggest the relevance of public and/or private interventions aimed at increasing consumer awareness of the direct link between olive oil's healthiness and its sensory profile. While current labelling policy promotes this health approach, consumers do not really pay much attention to it. Another remark by [START_REF] Cavallo | Extra-virgin olive oil: Are consumers provided with the sensory quality they want? A hedonic price model with sensory attributes[END_REF] was that the nutritional details given by the brands today are focused on chemical characteristics, which generally fail to catch the attention of the consumer enough to have a dissuasive effect. They recommended that firms make health claims easier for the consumer to understand, an incontestable way to increase the market for high-quality virgin olive oils. However, it is important to avoid consumers confusing an oil's "organic" label with the "healthiness" conferred by phenolic compound content [START_REF] Rizzo | Organic food consumption: The relevance of the health attribute[END_REF].

Unlike expert panels tasting EVOOs in blind conditions, consumers are influenced by packaging, label, and brand. A recent study involving 488 consumers in Thessaloniki [START_REF] Baziana | Branding influence on consumer behaviour regarding olive oil[END_REF] investigated the impact of branding on the behavior of Greek consumers regarding olive oil products. This survey revealed that preference for an olive oil brand is correlated with brand awareness, and that it is positively correlated with recognition of the label, quality perception, and loyalty. Research on the impact of religious and cultural information about olive oils [START_REF] Kitagawa | Effect of religious and cultural information of olive oil on consumer behavior: Evidence from Japan[END_REF] showed that Japanese consumers had a preference for Italian over Tunisian and Spanish olive oils, perhaps because they were familiar with Italy as the country of origin of olive oil. The rich cultural and religious background of the Mediterranean regions (largely Greco-Roman) is used to promote Mediterranean olive oils. [START_REF] Delgado | Evaluating bottles and labels versus tasting the oils blind: Effects of packaging and labeling on consumer preferences, purchase intentions and expectations for extra virgin olive oil[END_REF] found a link between liking, purchase intent, sensory and nutritional expectations of consumers and the packaging and labelling of commercial extra virgin olive oils. When EVOOs were certified as "organic", consumers gave them higher scores because of their expectations of higher nutritional value for organic products, even though the EVOOs tasted had strong bitterness and pungency and the consumers had expressed a dislike of bitter tastes. An analysis of the factors influencing Italian consumers' purchase of organic extra virgin olive oil confirmed that organic certification of extra virgin olive oil reminded them of safety, nutritional, and health aspects [START_REF] Liberatore | What's behind organic certification of extra-virgin olive oil? A response from Italian consumers[END_REF]. However, when different options are offered to consumers, the organic attribute becomes less important than local origin and origin certification, according to an investigation on Catalan consumers' behavior towards organic extra virgin olive oil [START_REF] Yangui | Comportamiento de los consumidores españoles y los fac-tores determinantes de sus disposiciones a pagar hacia el aceite de oliva ecológico[END_REF].

In addition to summarizing several aspects of quality, EVOO certification allows consumers to take a quick decision when shopping for oil [START_REF] Caracciolo | Consumers (Dis)Preference for bitterness in extra virgin olive oil: A field experiment[END_REF]. This supports the idea that quality olive oils need to be promoted and regularly consumed to be appreciated. This is particularly true for consumers who are relatively new to olive oil, and who should be offered the whole range of virgin olive oils (from robust green to delicate ripe fruitiness).

Conclusion

Many countries organize international olive oil competitions, even countries that are not major producers, either because olive oil is an integral part of the national culture, or because the competitions are aimed at exploiting olive oils' commercial potential elsewhere. In this case, the reputation of some producer countries in the Mediterranean basin is a significant asset. In addition to the competitive aspect, some competitions play social, technical, and commercial roles through the potential for exchanges between judges, producers, and consumers. The competitions differ in logistics-organization, type of tasters, tasting conditions, method of collecting scores, processing of scores, and nature of prizes awarded, which may lead to different results. From one international competition to another, there are differences in the sensory evaluation sheets used to rank the best extra virgin olive oils according to certain attributes, which are very specific and difficult to quantify, even by a tasting expert The division of fruitiness into two main categories, green and ripe, each of which is subdivided into three subcategories (delicate, medium, robust), can penalize producers who may sometimes have to submit their sample in one category and one sub-category. However, the borderline between these fruitiness categories is rather arbitrary, which can be an unfair advantage or disadvantage, especially when samples are close to this limit. The AVPA approach, which uses this categorization solely for the awarding of prizes, provides a solution to this problem. Generally based on the regulations for the IOC Mario Solinas, some competitions differ by focusing on the health aspect (phenolic compound content) or the oils' biological nature, or by introducing children to awareness of sensory properties, forming future tasting experts or informed consumers. The number of competitions with such special features is likely to grow in coming years.

Producers seek to participate in the competitions to enhance the value of their oils, recognized through the awards as high quality oils with high added value. The notoriety gained for their names, brands, and products grows when producers are regularly rewarded, as does their commercial visibility. However, participation requires significant efforts from the producers, especially financially. Moreover, certain competitions require producers to enter samples in a fruitiness category, which can raise real problems and questions for them.

The awards serve as a guide for consumer choice, but the number of competitions and prizes does not always help consumers to make the right choice. EVOO World Ranking's summarizing work on prizewinning oils from all international competitions is one way of informing consumers about the most frequently rewarded oils and producers. It appears, however, that consumers often do not appreciate the same types of oils as experts. Experts appreciate bitter and pungent olive oils, while consumers usually prefer olive oils with a mild sensory profile. Ultimately, however, it is the consumers who decide their preferences and thus guide the market. Training activities that introduce consumers to the diversity of fruity olive oils by informing them of their "health" aspect, their organoleptic diversity, and their gastronomic uses should enable them to better choose oils according to their own taste and to the uses they wish to make of them.

CRediT authorship contribution statement

Catherine Rébufa: Conceptualization, Writing -review & editing. Christian Pinatel: Conceptualization. Jacques Artaud: Conceptualization, Writing -review & editing. Fabien Girard: Conceptualization.

Table 1

 1 List of olive oil competitions, their website and the organizing country.

Italy Ovibeja https://www.ovibeja.pt (accessed December 14, 2019) Portugal Sol d'Oro Northern Hemisphere https://www.solagrifood.com/(accessed October 2, 2019) Italy Asian competitions Website Organizing country China International Olive Oil http://www.eoliveoil.com/olive-oil/oliveoilcompetition.html (accessed October 2, 2019) China Olive Japan http://olivejapan.com/en/competition (accessed September 25, 2019) Japan TERRAOLIVO https://www.terraolivo.org (accessed September 2, 2019) Israel Oceanian competition Website Organizing country Sol d'Oro Southern Hemisphere https://www.solagrifood.com/(accessed October 2, 2019) Italy Guides Website Organizing country EVOOLEUM https://www.evooleum.com/(accessed August 27, 2019) Spain Flos Olei http://www.flosolei.com/(accessed August 27, 2019) Italy GastrOleum https://gastroleum.com/(accessed August 27, 2019) Spain Iber Oleum http://wwww.iberoleum.es/(accessed August 27, 2019) Spain

Table 2

 2 Comparison of specific features of olive oil competitions and guides, based on 2019 regulations.

	Name	ATHIOOC	EVO IOOC	IOC Solinas	NYIOOC	Oil China IOOC	EVOOLEUM	OOAZ	JOOP	Leone d'Oro	Los Angeles	SIAL
	Country	Greece	Italy	Spain	USA	China	Spain	Switzerland	Japan	Spain	USA	Canada
	Total score	100	100	100	100	100	100			100	100	30
	Negative		X		X		X	X	X			X
	attributes
	Fusty-Muddy	(0-10)	X		X			(0-10)	(0-6)
	sediment
	Musty-Humid-	(0-10)	X		X			(0-10)	(0-6)
	Earthy
	Winey-Vinegary	(0-10)	X		X			(0-10)	(0-6)
	Acid-Sour								(0-6)
	Frostbitten							X
	olives
	Rancid	(0-10)	X		X			(0-10)	(0-6)
	Dry Hay		X
	Metallic	(0-10)			X			(0-10)
	Others	(0-10)	X		X			X	X
	Olfactory	35 points	35 points	35 points	35 points	35 points	50 points	X		45 points	20 points
	sensations

Table 2

 2 (continued )

	Name	ATHIOOC	EVO	IOC	NYIOOC	Oil China	EVOOLEUM	OOAZ	JOOP	Leone	Los	SIAL
			IOOC	Solinas		IOOC				d'Or	Angeles
	Equilibre									0-10
	Category of fruitiness				0-10					X	X
	Green			(0-10)
	Ripe			(0-10)
	Delicate/Soft	X	(1-3)		(0-3)					X	(2-10)
	Medium	X	(4-7)		(4-6)					X	(4-10)
	Robust/Intense	X	(8-10)		(7-10)					X	(5-10)

Table 3

 3 Special awards in olive oil competitions.

	Special prizes	Competitions
	Best of class (relative to the 3 intensity	Los Angeles
	categories)
	Best olive oil per country of origin	OOAZ, Los Angeles
	Best mono-varietal olive oil	EVO IOOC, Leone D'Oro, OOAZ, Oleario
		Aipo D'Argento
	Best entry per variety	ATHIOOC, EVO IOOC, Leone D'Oro
	Best blended (multi-varietal) olive oil	ATHIOOC, EVO IOOC, Leone D'Oro
	Best coupage	ATHIOOC, EVO IOOC, Leone D'Oro
	Best olive oil produced by a	ATHIOOC
	winemaker
	Best olive oil per region (or country)	ATHIOOC, Olive Japan, TERRAOLIVO
	Best organic or biologic	China Oil, Leone D'Oro, Oleario Aipo
		D'Argento, OOAZ
	Highest polyphenol content	LIOOC, JOOP
	Best infused olive oil	LIOOC
	Best flavored	EVOO IOOC, CIOO, Olive Japan
	Best of show or Top Winners or Top 10	Oleario Aipo D'Argento, Olive Japan,
		TERRAOLIVO
	Best society	TERRAOLIVO
	Best Kosher	TERRAOLIVO

Acknowledgments

The authors would like to acknowledge the following persons for providing supplementary details on the how their competition is run: Christine Cheylan, Jury President of Olive d'Or competition; Sandro Fulzi, Director of JOOP; Maria Paola Gabusi, Organizer of Leone d'Oro International Olive Oil Competition; Jean-Emmanuel Jourde, general secretary of AVPA; Maria Katsouli, Manager of ATHIOOC; George Kouvelis, General Manager of London Olive Oil; Antonio G. Lauro, President EVO IOOC; Gilbert Moity of OLéOMONDO website; the support team of NYIOOC and Marco Oreggia, curator and editor of Flos Olei.