METHOD FOR PRODUCING DEHYDRATED AVOCADOS BY MICROWAVE DRYING

Description

[0001] The present invention relates to the field of the preparation of dehydrated avocados and avocado oil obtained from dehydrated avocados.

[0002] The present invention relates more specifically to a process for preparing dehydrated avocados and to a process for preparing an avocado oil rich in unsaponifiable matter, both processes including a step of drying the avocado by microwave.

[0003] The avocado has become a staple food. Avocados are rich in oil, with lipids representing between 10 and 20% of the fresh fruit. This high fat content is indeed one of the defining characteristics of this fruit. The oil has been used for many years in cosmetics and pharmaceuticals. Furthermore, thanks to its nutritional properties, it is of significant interest as a cooking oil or dietary supplement, and global production continues to grow.

[0004] Crude or virgin avocado oils are generally extracted using a process called cold pressing, which involves mashing the fresh fruit, followed by separating the three phases—solid, oily, and aqueous—in a centrifugal decanter. A final polishing step using centrifugal clarification produces a perfectly clear oil. Other processes, such as cold pressing with the addition of solid additives or supercritical extraction, can also be used to produce virgin avocado oils.

[0005] Avocado oils can also be obtained from dried avocados. Heat treatment of the avocados reduces the residual moisture content of the fruit to less than 10%, making it possible to extract the oil using an organic solvent or by mechanical pressing.

[0006] However, such extraction processes involving heating the avocado, usually in an oven or with hot air, can lead to well-known secondary degradation reactions, such as Maillard reactions, or significant chemical changes, particularly in the presence of heat-sensitive substrates such as lipids (e.g., unsaturated fatty acids) and the unsaponifiable fraction (e.g., vitamin E). Thus, thermal processes promote the thermo-oxidation of substrates, radical reactions responsible for the formation of peroxides, and also intra- or intermolecular condensation reactions that lead to the formation of heavy products such as Maillard reactions.

[0007] Thus, the low stability of certain avocado constituents and the risks associated with their potential toxicity necessitate controlling the fate of these constituents during the various stages of the process to produce oil of cosmetic, pharmaceutical, or food quality. Consequently, there was a need to develop processes for obtaining crude or refined avocado oils that did not present the drawbacks of prior art and that allowed for the safe commercialization of oils derived from dried avocados.WO 2009 / 066259 discloses a process for preparing dehydrated avocados comprising the following steps: selecting avocados; cutting off the tip; removing the skin; slicing with the pit included; dehydrating to a moisture content of 0 to 2% by weight, applying a vacuum at an absolute pressure of between 0 and 200 mm Hg and microwave energy of between 0.5 watts per gram and 10 watts per gram; and removing the pit sections from the slices.

[0008] US 2011 / 091616 discloses a process for preparing dehydrated avocados comprising the following steps: a) providing a plurality of whole avocado fruits; b) washing the whole avocado fruits; c) cutting the whole avocado fruits into at least two portions; d) removing the pits from the fruits; e) first dehydrating the portions of avocado fruits in at least one air-fed microwave oven, until the maximum moisture content of the pulp is between 8 and 12% w / w; f) second dehydrating the fruit portions obtained in the first dehydration until the maximum moisture content is between 2 and 7% w / w; and e) grinding the remaining fruit portions after the second dehydration to a particle size of between 0.5 and 2.5 mm.

[0009] Patent application EP 1 966 358 discloses a process for obtaining refined avocado oil that substantially removes specific avocado impurities, such as acetogenins, also known as "persin," and degradation products responsible for bitterness. The process disclosed in EP 1 966 358 includes a molecular distillation step judiciously inserted between fruit drying and oil refining, enabling the removal of undesirable and unstable compounds.

[0010] The first step of the process disclosed in EP 1 966 358 is a controlled dehydration step of the avocados at a temperature preferably between 70 and 90°C. This step is generally carried out by oven drying or hot air drying and can last from 8 to 36 hours until a residual moisture content in the fruit is less than or equal to 5%.

[0011] International applications WO 2013 / 098293, WO 2013 / 104795, and WO 2013 / 104793 also disclose a process for obtaining crude avocado oil by mechanical pressing. The processes described in these applications all include a high-temperature drying step at a temperature between 60°C and 150°C, until a residual moisture content of 5% or less is achieved. In the examples provided in these applications, the drying step is carried out in an oven for 24 hours, or even 72 hours.

[0012] US 2004 / 018258 discloses a process for preparing an unsaponifiable fraction of avocado comprising the following successive steps: (1) a controlled dehydration step of fresh or preliminaryly processed avocados, carried out at a temperature between -50°C and 75°C; (2) a step of extracting oil from the dehydrated fruit; (3) a step, alternatively: a - Heat treatment of the extracted oil at a temperature advantageously between 80 and 150°C, then concentration of the oil into its unsaponifiable fraction, or b - Concentration of the oil into its unsaponifiable fraction, then heat treatment at a temperature advantageously between 80 and 150°C; and (4) a step of saponification and extraction of the unsaponifiable.

[0013] In the aforementioned applications, it is crucial to carefully control this drying stage to ensure that the dehydrated avocado has not been physically or chemically altered, and in particular that it still contains the compounds of interest for its nutraceutical, cosmetic, or pharmaceutical uses, notably the unsaponifiables. However, the drying methods used to date, particularly oven drying or hot air drying, are lengthy, energy-intensive, and do not allow for adapting the dryer capacity to varying quantities of avocados (the process is only suitable / cost-effective for quantities of tens of tons or more).

[0014] There is therefore a need to improve the avocado dehydration stage in order to obtain dehydrated avocado and / or avocado oil from dehydrated avocados, similar to those obtained with a dehydration stage by drying in an oven or with hot air, but consuming less energy, allowing for time savings, and providing access to great flexibility regarding the quantity of avocados to be dried (from a few tens of kg to a few tens of tons). SUMMARY OF THE INVENTION

[0015] The present invention meets the aforementioned needs.

[0016] Within the framework of the present invention, the inventors have discovered that it is possible to obtain dehydrated avocados, in particular having a residual moisture content of less than or equal to 5%, by a process comprising a microwave drying step.

[0017] The inventors have notably discovered specific microwave drying conditions that allow for the production of whole dehydrated avocados with a residual moisture content of less than or equal to 5%, despite the fact that the different parts of the avocado (skin, pit and pulp), taken individually, react differently to microwave drying.

[0018] The inventors discovered that, in order to obtain dehydrated avocados with a residual moisture content of 5% or less using a microwave drying step, it is necessary to remove the water evaporated by microwaves with a hot air flow at a temperature of 80°C or less and a flow rate of 150 m³ / h or more. Similarly, it is also necessary to select whole, fresh avocados of medium to firm firmness and slice them.

[0019] The inventors have more specifically discovered that the implementation of a microwave drying step, under particular conditions, did not deteriorate the characteristics of the dehydrated avocado thus obtained, nor of the oil obtained from said dehydrated avocados.

[0020] Thus, it has been discovered that a microwave drying step makes it possible to obtain a dehydrated avocado and / or avocado oil from dehydrated avocados, similar to those obtained with a dehydration step by oven drying or hot air, but consuming less energy and allowing a substantial saving of time as well as greater flexibility of use with regard to the quantity of avocados to be dried.

[0021] The present invention makes it possible in particular to obtain an oil having a similar or even better unsaponifiable content and quality than that obtained in the prior art using drying steps in an oven or with hot air, for example.

[0022] Similarly, the present invention makes it possible to obtain cakes having a sugar content and in particular specific avocado sugars in C7, similar or even better than that obtained in the prior art using drying steps in an oven or with hot air for example.

[0023] The present invention relates first to a process for preparing dehydrated avocados comprising the following steps: a) select fresh avocados having a resistance to penetration into the flesh greater than 1 kg / cm², said resistance being measured using a penetrometer; b) slice the selected avocados; and c) dry the avocado slices obtained in step b) by microwave until dehydrated avocados are obtained with a residual moisture content of less than or equal to 5%, during this step the water evaporated under the action of the microwaves being removed by means of a flow of hot air of temperature less than or equal to 80°C at a flow rate greater than or equal to 150 m³ / h.

[0024] The present invention also relates to a process for preparing an avocado oil rich in unsaponifiable matter, comprising the following steps: a) Select fresh avocados with a resistance to penetration into the flesh greater than 1 kg / cm², said resistance being measured using a penetrometer; b) Slice the selected whole avocados into strips; c) Dry the avocado strips obtained in step b) by microwave until dehydrated avocados are obtained with a residual moisture content of less than or equal to 5%, during this step the water evaporated under the action of the microwaves being removed by means of a flow of hot air at a temperature less than or equal to 80°C at a flow rate greater than or equal to 150 m³ / h; d) Optionally, crush the dehydrated avocados obtained in step c); e) Extract the oil from the dehydrated avocados obtained in step c) or d), preferably by mechanical pressing; and f) Recover the oil obtained, preferably by filtration.

[0025] The present invention has as its third object a process for preparing a sugar-rich avocado cake comprising the following steps: a) Select fresh avocados with a resistance to penetration into the flesh greater than 1 kg / cm², said resistance being measured using a penetrometer; b) Slice the selected whole avocados into strips; c) Dry the avocado strips obtained in step b) by microwave until dehydrated avocados are obtained with a residual moisture content of less than or equal to 5%, during this step the water evaporated under the action of the microwaves being removed by means of a flow of hot air at a temperature less than or equal to 80°C at a flow rate greater than or equal to 150 m³ / h; d) Optionally, crush the dehydrated avocados obtained in step c); e) Extract the oil from the dehydrated avocados obtained in step c) or d), preferably by mechanical pressing; and f') Recover the resulting press cake. DETAILED DESCRIPTION OF THE INVENTION DEFINITION

[0026] The term "soft avocado" or "low-hardness avocado" refers, for the purposes of this invention, to an avocado with a penetration resistance force in the flesh of 1 kg / cm² or less. The term "medium-hardness avocado" refers, for the purposes of this invention, to an avocado with a penetration resistance force in the flesh greater than 1 kg / cm² and less than or equal to 3 kg / cm². The term "hard avocado" or "high-hardness avocado" refers, for the purposes of this invention, to an avocado with a penetration resistance force in the flesh greater than 3 kg / cm². Typically, according to the present invention, the penetration force is measured using a penetrometer of the PCE-PTR 200 or FT 327 type, which measures the force in kilograms required to penetrate a calibrated tip into the fruit.Advantageously, the fruit is peeled before measurement to eliminate the resistance of the skin (seed) and the variability between different avocado varieties tested. The rod, called a point or tip, used for this measurement has a nominal diameter of approximately 6 to 11.3 mm.

[0027] The term "whole avocado" is meant, in the context of the invention, to avocados containing the skin, pulp and pit distributed in their entirety.

[0028] The term "pitless" avocados, in the context of the present invention, refers to whole avocados from which the pit has been removed, and which thus contain only the skin and pulp.

[0029] The term "skinless" avocados, in the context of the present invention, refers to whole avocados from which the skin has been removed, and which thus contain only the pulp and the pit.

[0030] The term "unsaponifiable matter," as used in this invention, refers to all the constituents of a fat that, after saponification in a strongly alkaline medium, are very sparingly soluble or insoluble in water, but soluble in organic solvents such as ethyl ether, aromatic hydrocarbons, chlorinated solvents, MeTHF, etc. The unsaponifiable matter is therefore composed of all the non-hydrolyzable constituents of the fat, as well as those resulting primarily from the saponification of non-glyceride esters of fatty acids (sterol esters, waxes, tocopherol esters, etc.). Four main groups or families of substances are generally present in most vegetable oil unsaponifiables. The largest group by mass is comprised of sterols, including pentacyclic triterpenoid alcohols and 4-methylsterols. The second group consists of tocopherols that can incorporate tocotrienols.The other two groups are aliphatic alcohols and saturated and unsaturated aliphatic hydrocarbons. The composition of avocado unsaponifiables differs from that typically found in vegetable oils because it primarily incorporates constituents specific to avocados. The major fraction of avocado unsaponifiables is represented by the acetogenin group, which are precursor compounds of aliphatic furans. The second family of molecules comprises polyhydroxylated fatty alcohols. The third group consists of sterols, including pentacyclic triterpene alcohols and 4-methylsterols. The other groups are present in smaller quantities.

[0031] For the purposes of this invention, the term "rich in unsaponifiables" refers to an oil that typically comprises at least 3% by mass of unsaponifiable matter, advantageously at least 5% by mass of unsaponifiable matter, relative to the total mass of the oil. For example, the oil comprises between 3% and 15% by mass of unsaponifiable matter, advantageously between 5% and 15%, in particular 5% to 12%, more particularly 8% to 12%, by mass of unsaponifiable matter, relative to the total mass of the oil.

[0032] For the purposes of this invention, the term "sugar" refers to all carbohydrate substances present in avocados, and in particular all water-soluble sugars in avocados. These carbohydrate substances can be monosaccharides (such as C7 sugars), oligosaccharides, polysaccharides, and / or sugar alcohols (such as perseitol). Avocados are particularly rich in sugars containing 7 carbon atoms, commonly known as "C7 sugars," including D-mannoheptulose and / or perseitol.

[0033] The term "avocado press cake" refers, in the context of this invention, to the solid residue obtained after the extraction of avocado oil. The press cake is typically obtained after filtering and separating the avocado oil extracted from dehydrated avocados.

[0034] The term "high-sugar avocado press cake" refers, for the purposes of this invention, to avocado press cake typically comprising at least 5% by mass of sugars, advantageously at least 10% by mass of sugars, more advantageously from 5 to 15% by mass of sugars, and in particular from 10 to 15% by mass of sugars, relative to the total mass of the press cake. The sugars present in the avocado press cake according to the invention advantageously comprise at least 80% C7 sugars, including mannoheptulose and perseitol, and non-avocado-specific sugars such as fructose, sucrose, and glucose. For example, mannoheptulose will represent at least 35% of the sugars and perseitol will represent at least 35% of the sugars, relative to the total mass of sugars contained in the press cake.

[0035] For the purposes of this invention, the term "protein" refers to all the proteins in avocados. A protein is a macromolecule composed of one or more chains of at least fifty amino acids called polypeptides, to which various groups are often added, and possessing a three-dimensional structure. Proteins typically have a molecular weight greater than 10,000 Da.

[0036] The term "residual moisture," as used in the present invention, refers to the amount of liquid water contained in a sample of material after it has been subjected to a drying process. It is evaluated by a weight or volume ratio. Residual moisture can be determined by methods well known to those skilled in the art, particularly using a thermogravimetric method with infrared drying. Other methods can also be employed, such as the loss-on-drying method or the Karl Fischer titration method. Item 1 - Method for preparing dehydrated avocados

[0037] The present invention relates first to a process for preparing dehydrated avocados comprising the following steps: a) select fresh avocados having a resistance to penetration into the flesh greater than 1 kg / cm², said resistance being measured using a penetrometer; b) slice the selected avocados; and c) dry the avocado slices obtained in step b) by microwave until dehydrated avocados are obtained with a residual moisture content of less than or equal to 5%, during this step the water evaporated under the action of the microwaves being removed by means of a flow of hot air of temperature less than or equal to 80°C at a flow rate greater than or equal to 150 m³ / h.

[0038] The present invention therefore has as its first object a process as described above for the preparation of dehydrated avocados having a residual moisture content of less than or equal to 5%.

[0039] Most avocado varieties can be used in the context of the present invention to produce dehydrated avocados. For example, the process according to the invention can be applied to the following, non-exhaustive list of avocado varieties: Bacon, Collin, Duke, Edranol, Ettinger, Fuerte, Hass, Lula, Maluma, Mexicana, Nabal, Nava, Pinkerton, Queen, Ryan, Sultan, and Superfuerte.

[0040] The avocados used as a starting product are whole avocados.

[0041] In the context of the present invention, fresh avocados must be selected according to their ripeness. Indeed, due to the fruit's three distinct parts—skin, pulp, and pit—the avocado's behavior during slicing will vary considerably depending on its degree of ripeness and the firmness of the pulp and skin. In the initial phase following harvesting, the fruit exhibits a homogeneity of structure and hardness across all three parts, making it easy to slice; this is referred to as a firm avocado. Once the pulp begins to soften, the compartmentalized hardness of the fruit (pulp, skin, pit) becomes highly uneven, limiting industrial slicing due to the presence of the very hard pit and the loss of consistency in the skin and pulp.Furthermore, drying whole soft fruits without preparation does not give satisfactory results, as it leads to heterogeneous drying with residual free water, which is favorable to the appearance of parasitic and heterogeneous reactions, factors in the degradation of the oil and its unsaponifiable matter.

[0042] Thus, within the scope of the present invention, the fresh avocados selected in step a) are not soft avocados. Typically, soft avocados have a degree of softening equivalent to that of immediate consumption, and preclude slicing. The avocados selected in step a) therefore have a resistance to penetration into the flesh greater than 1 kg / cm², preferably greater than or equal to 2 kg / cm², said resistance being measured using a penetrometer.

[0043] Advantageously, the avocados selected in step a) are hard avocados, that is to say avocados having a resistance force to penetration into the flesh greater than 3 kg / cm 2<, said force being measured using a penetrometer.

[0044] In step b) of the process according to the invention, the slicing of the avocados is advantageously carried out using a disc slicer.

[0045] Advantageously, in step b), the whole avocados are sliced ​​into strips 1 to 5 mm thick, more advantageously 1 to 3 mm thick, in particular 2 mm thick.

[0046] It has been discovered that slicing avocados affects the homogeneity and final quality of the resulting dehydrated avocados. For example, slicing avocados into cubes does not allow the fruit to dry completely, resulting in dehydrated avocados with more than 5% residual moisture and an alteration of the unsaponifiable content of the oil obtained.

[0047] In the context of the present invention, the drying of fresh avocado slices is achieved by microwave heating combined with a flow of hot air.

[0048] The unique characteristic of microwave heating is that it heats from the inside out. Some water molecules begin to vaporize, creating partial pressures within the cells that expel the remaining unvaporized water molecules. This creates a wringing effect that allows for the extraction of a maximum amount of water with a minimum of energy. However, for maximum efficiency, and particularly to achieve a residual humidity of 5% or less, it has been discovered that the extracted water must be removed from the microwave chamber, preferably continuously.

[0049] Thus, during step c) of the process according to the invention, the water evaporated under the action of microwaves is eliminated by means of a hot air flow of temperature less than or equal to 80°C at a flow rate greater than or equal to 150 m³ / h, advantageously by a hot air flow of temperature less than or equal to 80°C, more advantageously at a temperature less than 80°C, in particular at a temperature between 40°C and 80°C, more particularly at a temperature between 40°C and 60°C.

[0050] Advantageously, the flow rate of this hot air stream is between 200 and 500 m³ / h.

[0051] Within the framework of the present invention, the microwave power must be adjusted to allow for rapid drying of the avocados while preserving compounds of interest such as sugars and unsaponifiables and preventing the avocados from catching fire. Advantageously, in step c), the microwave power is between 1000 and 5000 W, preferably between 2000 and 5000 W, particularly between 2500 and 5000 W, especially for equipment operating at a microwave frequency of 2450 MHz.

[0052] Depending on the microwave power setting and the quantity of avocados to be dried, the drying time (step c) should be adjusted. Higher power settings generally mean shorter drying times. Similarly, larger quantities of avocados require longer drying times. Therefore, the drying time should be adjusted based on the drying yield achieved at a given microwave power setting.

[0053] Advantageously, for a microwave power between 1000 and 5000 W, the drying time is determined by considering that the drying yield is between 10 g and 2000 g, advantageously between 350 g and 2000 g, more advantageously between 700 g and 2000 g, in particular between 1250 g and 2000 g, of avocado slices obtained in step b) dried in 1 minute.In particular, for a microwave power between 1000 and 3000 W, the drying time is determined by considering that the drying yield is between 10 g and 700 g, advantageously between 350 g and 700 g, more advantageously between 500 g and 700 g, in particular between 600 g and 700 g, of avocado slices obtained in step b) dried in 1 minute, and for a microwave power between more than 3000 and 5000 W, the drying time is determined by considering that the drying yield is between 15 g and 2000 g, advantageously between 700 g and 2000 g, more advantageously between 1000 g and 2000 g, in particular between 1500 g and 2000 g, of avocado slices obtained in step b) dried in 1 minute.

[0054] The conditions selected for carrying out the drying in step c) are established with the aim of obtaining dehydrated avocados with a residual moisture content of 5% or less, advantageously less than 5%, and more advantageously less than 4%, while preserving the quality of the dehydrated avocados and, in particular, preserving compounds of interest such as sugars and unsaponifiables. Step c) of the process according to the invention is thus carried out under conditions that optimize energy requirements and limit undesirable reactions.

[0055] The said dehydrated avocado has a residual moisture content of 5% or less, advantageously less than 5%, more advantageously less than 4%, and advantageously has a green to light brown color. Furthermore, the said dehydrated avocado advantageously has a "crisp" texture, unlike freeze-dried fruit, which generally has a "soft" texture.

[0056] A residual moisture content of 5% or less plays a crucial role in the consistency of dried avocados, giving them a firm, brittle texture that helps them withstand the physical stresses generated during mechanical pressing. Above 5% moisture, dried avocados have a soft consistency which, when pressed, results in a mush lacking the firmness necessary for effective pressing.

[0057] In an advantageous embodiment, the present invention relates to a process for preparing dehydrated avocados with a residual moisture content of less than or equal to 5%, comprising the following steps: a) select fresh avocados having a resistance to penetration into the flesh greater than 1 kg / cm², said resistance being measured using a penetrometer; b) slice the selected whole avocados into strips, advantageously 1 to 5 mm thick, more advantageously 1 to 3 mm thick, in particular 2 mm thick; and c) dry the avocado strips obtained in step b) by microwave until dehydrated avocados are obtained with a residual moisture content of less than or equal to 5%, during this step the water evaporated by the action of the microwaves being removed by means of a hot air flow at a temperature between 40°C and 80°C, with a hot air flow rate greater than or equal to 150 m³ / h, more advantageously between 180 and 500 m³ / h, In addition, during step c), the microwave power is between 1000 and 5000 W, preferably between 2000 and 5000 W, in particular between 2500 and 5000 W. Item 2 - Method for preparing an avocado oil rich in unsaponifiables

[0058] The present invention also relates to a process for preparing an avocado oil rich in unsaponifiable matter, comprising the following steps: a) Select fresh avocados with a resistance to penetration into the flesh greater than 1 kg / cm², said resistance being measured using a penetrometer; b) Slice the selected whole avocados; c) Dry the avocado slices obtained in step b) by microwave until dehydrated avocados with a residual moisture content of less than or equal to 5% are obtained, during this step the water evaporated under the action of the microwaves being removed by means of a flow of hot air at a temperature less than or equal to 80°C at a flow rate greater than or equal to 150 m³ / h; d) Optionally, crush the dehydrated avocados obtained in step c); e) Extract the oil from the dehydrated avocados obtained in step c) or d), preferably by mechanical pressing; and f) Recover the oil obtained, preferably by filtration.

[0059] In the context of this second object of the invention, steps a) to c) are identical to those described in the process for preparing dehydrated avocados (first object). Therefore, the portion concerning object 1 of the invention is reproduced here in its entirety.

[0060] The optional step d) of crushing the dehydrated avocados obtained in step c) can be carried out to facilitate the transport and storage of the dehydrated avocados to the pressing system. This step can be carried out using methods known to those skilled in the art, such as a crusher (jaw, impact, cone), a grinder (hammer, blade, roller), a chopper, or a mill.

[0061] The oil extraction step (e) is implemented by mechanically pressing the dry material, after implementation of the drying step c) or crushing step d).

[0062] Advantageously, the extraction step (e) is carried out at a temperature between 80 and 100°C. This temperature is obtained and maintained constant by all available means such as preheating the press body, preheating the dried avocados then mixed with water in the press feed, heating the press body, etc.

[0063] In particular, maintaining the working temperature of the press at a value above 80°C, more particularly at 100°C, ensures a good level of oil extraction and significantly improves the extraction yield of unsaponifiable constituents, including acetogenins, aliphatic alcohols, sterols and / or saturated aliphatic hydrocarbons.

[0064] The extraction step (e) according to the invention is generally completed by a filtration which removes solid particles and ensures the clarity of the oil produced.

[0065] The process according to the present invention makes it possible to produce a quality avocado oil with a particular composition, in particular having a low acid value and a high unsaponifiable potential and a particular composition of this unsaponifiable.

[0066] The said avocado oil is an oil rich in unsaponifiable matter. Advantageously, the oil contains at least 3%, more advantageously at least 5%, by mass of unsaponifiable matter, relative to the total mass of the oil.

[0067] Advantageously, the unsaponifiable portion of the oil contains the following molecular families: saturated and unsaturated hydrocarbons, terpenic and aliphatic alcohols, sterols, tocopherols, carotenoids, and xanthophylls.

[0068] Advantageously, the unsaponifiable fraction of the oil comprises 0 to 5% by mass of saturated aliphatic hydrocarbons. In particular, these saturated aliphatic hydrocarbons are typically linear, unbranched hydrocarbons with an odd number of carbon atoms. Advantageously, the saturated aliphatic hydrocarbons are C27, C29, or C31 alkanes.

[0069] Advantageously, the oil contains at least 0.5% by mass of sterols, advantageously at least 0.8% by mass of sterols, relative to the total mass of the oil. In particular, said sterols are advantageously selected from the group consisting of β-Sitosterol, Campesterol, Stigmasterol, Δ5-Avenasterol, Δ7-Stigmasterol, Citrostadienol, and mixtures thereof.

[0070] Advantageously, the unsaponifiable matter contained in the oil also contains aliphatic acetogenins and / or their derivatives.

[0071] Within the scope of the invention, aliphatic acetogenins and their derivatives include polyhydroxylated fatty alcohols and their acetylated derivatives, and / or 1,2-dihydroxy-4-oxo-aliphatic alcohols and their acetylated derivatives of the "persins" type, and / or aliphatic furans, as well as mixtures thereof.

[0072] Polyhydroxylated fatty alcohols are also known as Fraction I. These include 1,2,4-trihydroxy triols with long acetylenic and olefinic chains. Acetylated derivatives of polyhydroxylated fatty alcohols are typically found at positions 1, 2, or 4.

[0073] 1,2-Dihydroxy-4-oxo-aliphatic alcohols are also called persins and are precursors of the H fraction, i.e., aliphatic furans. These include long-chain acetylenic and olefinic ketone diols of the 1,2-dihydroxy-4-oxo type. The acetylated derivatives of these compounds are typically in the 1 position.

[0074] Persins are typically found in idioblasts, oil-producing cells in the case of avocado.

[0075] For example, we can specifically mention individuals with the following molecular structure:

[0076] Aliphatic furans are also called furanic lipids, or more commonly avocado furans or Fraction H. These are derivatives of persins containing a furan group, resulting in particular from the chemical transformation of persins extracted from avocados through dehydration and intramolecular cyclization. 2-Alkyl furans are an example.

[0077] Advantageously, the unsaponifiable fraction of the oil is rich in aliphatic acetogenins and / or their derivatives. Particularly advantageously, the oil typically contains at least 2% by mass of aliphatic acetogenins and / or their derivatives, and typically at least 3% by mass of aliphatic acetogenins and / or their derivatives, relative to the total mass of the oil. For example, the oil contains between 2% and 10%, and more specifically between 3% and 10%, and more particularly between 5% and 8% by mass of aliphatic acetogenins and / or their derivatives, relative to the total mass of the oil.

[0078] The present invention also relates to a process for preparing an avocado unsaponifiable comprising steps a) to f) mentioned above as well as the following steps: (g) Alternatively: (i) Heat treatment of the extracted oil at a temperature advantageously between 80 and 150°C, then concentration of the oil into its unsaponifiable fraction, or (ii) Concentration of the oil into its unsaponifiable fraction, then heat treatment at a temperature advantageously between 80 and 150°C, (h) followed by a saponification step and extraction of the unsaponifiable, (i) and possibly at least one purification and / or fractionation.

[0079] The step of concentrating the oil into its unsaponifiable fraction to prepare a concentrate, carried out in step (g)i. or (g)ii., is advantageously performed by cold crystallization or molecular distillation. Advantageously, the avocado oil unsaponifiable concentrate is prepared by molecular distillation, typically at a temperature between 180°C and 260°C, maintaining a pressure between 10⁻² and 10⁻³ mmHg.

[0080] This molecular distillation step of avocado oil is preferably carried out using a device chosen from among centrifugal type molecular distillers and scraped film type devices.

[0081] The heat treatment step of the oil or concentrate, implemented in step (g)i. or (g)ii., is generally carried out at a temperature between 80°C and 150°C, for example between 80°C and 130°C.

[0082] The process for preparing avocado unsaponifiables further includes a step (h) of saponification and extraction of the unsaponifiables, for example using a solvent.

[0083] In particular, step (h) of saponification and extraction of the unsaponifiable matter can be carried out in the presence of potassium hydroxide or sodium hydroxide in an alcoholic, preferably ethanolic, medium, followed by one or more extractions. Extraction with a suitable organic solvent (liquid-liquid extraction) to separate the fatty acid soaps and unsaponifiable compounds is particularly appropriate. The suitable organic solvent may be, for example, chosen from the group of alkanes, halogenated alkanes, aromatic and halogenated aromatic solvents, ethers, ketones, esters, solvents containing at least one silicon atom, or any other suitable solvent immiscible with the hydro-alcoholic solution.

[0084] Following the extraction of the unsaponifiable, additional steps can be taken (i) of purification or fractionation.

[0085] The said unsaponifiable contains at least 45%, more advantageously from 45% to 78%, by mass of furanic lipids, relative to the total mass of the unsaponifiable.

[0086] Advantageously, the unsaponifiable also contains at least 3%, more advantageously 3 to 8%, by mass of sterols, relative to the total mass of the unsaponifiable.

[0087] Advantageously, the unsaponifiable also contains at least 0.5%, more advantageously from 0.5 to 5%, by mass of squalene relative to the total mass of the unsaponifiable.

[0088] Advantageously, the unsaponifiable also contains 0 to 5% by mass of saturated aliphatic hydrocarbons, relative to the total mass of the unsaponifiable. Item 3 - Process for preparing a cake rich in sugars and proteins

[0089] The present invention has as its third object a process for preparing a sugar-rich avocado cake comprising the following steps: a) Select fresh avocados with a penetration resistance greater than 1 kg / cm², said resistance being measured using a penetrometer; b) Slice the selected whole avocados; c) Microwave the avocado slices obtained in step b) until dehydrated avocados with a residual moisture content of 5% or less are obtained, during this step the water evaporated by the microwaves being removed by a flow of hot air at a temperature of 80°C or less at a flow rate of 150 m³ / h or more; d) Optionally, crush the dehydrated avocados obtained in step c); e) Extract the oil from the dehydrated avocados obtained in step c) or d), preferably by mechanical pressing; and f') Recovery of the resulting cake, preferably after filtering the oil obtained in step e).

[0090] In the context of this third object of the invention, steps a) to c) are identical to those described in the process for preparing dehydrated avocados (first object). Therefore, the portion concerning object 1 of the invention is reproduced here in its entirety.

[0091] Similarly, steps d) and e) are identical to those described in the process for preparing avocado oil rich in unsaponifiable matter (second object of the invention). Therefore, the sections concerning steps d) and e) mentioned in object 2 of the invention are reproduced here in their entirety.

[0092] Finally, step f') is advantageously carried out in a similar manner to step f) mentioned in the context of the process for preparing an avocado oil rich in unsaponifiable matter (second object of the invention), except that it is the press cake and not the oil that is subsequently recovered.

[0093] Advantageously, the said cake comprises at least 5% sugars, in particular 5% to 15% sugars, more particularly 10% to 15%, expressed by weight in relation to the total weight of the cake.

[0094] Sugars are advantageously chosen from C7 sugars such as Mannoheptulose and Perseitol, and non-avocado sugars such as Fructose, Sucrose and Glucose. Advantageously, the meal comprises at least 5% protein, in particular 5% to 10%, more particularly 6% to 10%, expressed by weight relative to the total weight of the meal.

[0095] The proteins are advantageously chosen from the storage and structural proteins specifically present in the whole avocado fruit. The following examples are intended to illustrate the present invention. EXAMPLES Examples: analysis of the influence of operating conditions on microwave drying according to the invention THE EQUIPMENT

[0096] Krups Electric Slicer, Retsh GM200 Grinder, KOMET Press, Thermoscientific Centrifuge, Büchner Filter, Allcat FT 327 Penetrometer, Memmert Oven, Closed Rotating Turntable Microwave Chamber, Extractor 200 Type Closed Microwave Chamber, Continuous Belt Microwave Chamber, Continuous Screw Microwave Chamber EXPERIMENTAL PROCEDURE has) Protocol for drying fresh avocados by steaming (control) :

[0097] Fresh, hard avocados are thinly sliced ​​into 1-2 mm strips and then spread over the 2 trays of the oven to obtain a layer of 2 cm maximum thickness (800 g of avocados per tray).

[0098] They are dried immediately in an oven at T=80 ± 5°C, until the fruits are dry both externally and internally, and are green to light brown in color.

[0099] Residual moisture is checked using infrared technology (on finely ground product).

[0100] The goal is to achieve a residual moisture content of 5% or less; therefore, drying is stopped as soon as the fruit's residual moisture reaches this target. The fruit should remain green to light brown in color. b) Pilot-scale microwave drying protocol for fresh avocados :

[0101] Fresh avocados are sliced ​​into 1-2 mm strips with the help of an electric slicer and then immediately dried in a closed microwave oven with a rotating tray equipped with a microwave generator.

[0102] As part of the process of optimizing operating conditions, the various tests carried out made it possible to test the impact of the following parameters: Microwave power; Airflow temperature; Drying time; Airflow rate; Ripeness of avocados; Size of avocado pieces; and Temperature of avocados after drying. c) Oil extraction protocol :

[0103] Dried avocados are crushed and then pressed using a screw press. The crude oil is centrifuged, filtered, and analyzed. d) Oil analysis protocol :

[0104] The oil is analyzed by Gas Chromatography to determine its unsaponifiable content. The analysis is carried out according to the following principle: saponification of a test portion containing cholestanol and squalane as internal standards, extraction of the unsaponifiable matter, and then quantification of sterol silylethers, the "H", "IA" fractions, and squalene by gas chromatography on a capillary column. e) Oilcake extraction and analysis protocol :

[0105] Total sugars are extracted with demineralized water. After stirring and centrifugation, the supernatant is collected and analyzed by HPLC to determine the sugar profile of the total extract.

[0106] The protein content of the oilseed cake is determined by the Kjeldahl method. Example 1: Microwave power a) LAWYERS

[0107] Fresh, firm avocados of the Hass variety, originating from Peru, have been supplied. The approximate size of the fruits is 200 g. b) DETAILED EXPERIMENTAL PROCEDURE b1) Comparison: Drying of fresh avocados by steaming (control)

[0108] The results of the control test are shown in Table 1: Table 1: Results of the Example 1 Control Test Drying time (h, min', sec") Drying temperature (°C) Humidity (relative percentage) % unsaponifiable (in oil) % sugars (in the oilseed cake) 8h 80 2.5 13.0 10.8 b2) Invention: Microwave drying of fresh avocados on a laboratory scale

[0109] Fresh, firm avocados were sliced ​​into 1-2 mm strips and then immediately dried in a closed, rotating-turntable microwave oven equipped with a microwave generator whose power was successively adjusted from 600 to 5000 W. The drying time was adjusted according to the selected power level to achieve a residual moisture content of 5% or less without damaging the fruit. The microwave frequency was set at 2450 Hz, and the airflow temperature was set at 20°C for the first five trials and at 60°C for the last two trials.

[0110] The various tests carried out made it possible to test the impact of power: Results (Table 2):

[0111] Table 2: Test results according to microwave power Power (W) Drying time (min) Humidity (relative percentage) % unsaponifiable (in oil) % sugars (in the oilseed cake) 600 33 16.7 ND ND 1200 15 9.0 ND ND 3200 8 9.4 10.7 9.5 4800 5 5.6 19.0 10.6 5000 5 flames ND ND 800 27.6 3.9 10.8 9.5 1000 21.6 3.5 11.3 10.4 Conclusions

[0112] Higher microwave power is more important for efficient drying. This high power allows for rapid drying of avocados while preserving their unsaponifiable content. However, a 5000W microwave can cause very rapid drying of the fruit, potentially leading to a fire. Therefore, it is necessary to adjust the exposure time accordingly.

[0113] These tests were conducted to analyze the influence of microwave power on the drying of avocados. However, the first five tests are not representative of the invention since the hot air generator providing ventilation for the chamber was not used in this instance. Example 2: Airflow temperature a) LAWYERS

[0114] Fresh, medium-hardness avocados of Chilean origin, Hass variety, were supplied. The approximate size of the fruits is 200 g. b) DETAILED EXPERIMENTAL PROCEDURE b1) Comparison: Drying of fresh avocados by steaming (control)

[0115] The results of the Control test are shown in Table 3: Table 3: Test Results - Control of Example 2 Drying time (h, min', sec") Drying temperature (°C) Humidity (relative percentage) % unsaponifiable (in oil) % sugar (in the press cake) 8h 80 4.2 8.0 11.3 b2) Invention: Microwave drying of fresh avocados on a pilot scale:

[0116] Approximately 550 g of fresh, medium-hardness avocados (>1 and ≤3 kg / cm²) are sliced ​​into 1-2 mm slices using an electric slicer and then immediately dried on the Extractor 200 unit, which has a 5 L bowl and a microwave generator set at 1000 W and 2450 Hz. A hot air generator provides ventilation for the chamber. The average drying time is approximately 22 minutes.

[0117] The various tests carried out made it possible to test the impact of the temperature of the blown air: Results (Table 4):

[0118] Table 4: Test results according to airflow temperature Airflow temperature (°C) Humidity (relative percentage) % unsaponifiable (in oil) % sugars (in the oilseed cake) 40 11.0 10.6 10.2 60 4.7 10.7 13.2 80 2.9 9.1 6.9 Conclusions

[0119] The presence of a hot airflow allows for faster and more efficient drying. From 60°C, the required moisture content is quickly achieved while preserving the unsaponifiable components. Below 60°C, drying is possible, but a longer microwave exposure time is required. At 80°C, a change in the sugar content of the avocado press cake is observed (a 38.9% decrease in sugars compared to the control oil obtained with oven-dried avocados). Example 3 : Drying time a) LAWYERS

[0120] Fresh, medium-hardness avocados of Chilean origin, Hass variety, were supplied. The approximate size of the fruits is 200 g. b) DETAILED EXPERIMENTAL PROCEDURE b1) Comparison: Drying of fresh avocados by steaming (control):

[0121] The results of the Control test are shown in Table 5: Table 5: Results of the Control Test of Example 3 Drying time (h, min', sec") Drying temperature (°C) Humidity (relative percentage) % unsaponifiable (in oil) 8h 80 3.7 13.7 b2) Invention: Drying fresh avocados by microwave in continuous mode:

[0122] Approximately 300 g of fresh, medium-firm avocados are sliced ​​into 1-2 mm strips using an electric slicer and then immediately dried in a continuous conveyor microwave chamber equipped with a microwave generator set to a power of 3000 W and a frequency of 2450 Hz. A hot air generator at 80°C provides ventilation for the chamber.

[0123] The various tests carried out made it possible to test the impact of drying time. Results (Table 6):

[0124] Table 6: Test results according to drying time Drying time (h, min', sec") Humidity (relative percentage) % unsaponifiable (in oil) 11'30" 10.5 9.3 15' 3.8 8.1 18'40" 2.7 13.9 Conclusions

[0125] The water content in avocados decreases over the duration of exposure to microwaves.

[0126] The drying time must allow for a residual moisture content of ≤ 5%, in accordance with our specifications, to preserve the chemical integrity of the unsaponifiables. Therefore, the drying yield can be defined as the quantity of fresh avocados whose residual moisture content has been reduced to less than 5% in one minute. Example 4: Supply air flow rate a) LAWYERS

[0127] Fresh, medium-hardness avocados of Chilean origin, Hass variety, were supplied. The approximate size of the fruits is 200 g. b) DETAILED EXPERIMENTAL PROCEDURE b1) Comparison: Drying of fresh avocados by steaming (control) Control Test Results (Table 7):

[0128] Table 7: Test Results - Control of Example 4 Drying time (h, min', sec") Drying temperature (°C) Humidity (relative percentage) % unsaponifiable (in oil) 8h 80 3.7 13.7 b2) Invention: Drying fresh avocados by microwave in continuous mode:

[0129] Approximately 300 g of fresh, medium-hard avocados are sliced ​​into 1-2 mm strips using an electric slicer and then immediately dried in a continuous conveyor belt microwave chamber equipped with a 3000 W generator and a frequency of 2450 Hz. A hot air generator at 80°C provides ventilation for the chamber.

[0130] The various tests carried out made it possible to test the impact of the flow rate of the blown air: Results (Table 8):

[0131] Table 8: Test results according to airflow Airflow rate (m³ / h) Humidity (relative percentage) % unsaponifiable (in oil) 120 10.5 9.3 180 3.8 8.1 210 2.7 13.9 Conclusions

[0132] Insufficient airflow prevents effective drying of avocado slices. Ideally, the airflow should be powerful enough to continuously remove the water vapor generated during the drying process. This preserves the unsaponifiable content. The airflow should preferably be at least 50 m³ / h, and ideally between 50 and 500 m³ / h, or more specifically between 180 and 500 m³ / h. Example 5: Maturity level of lawyers a) LAWYERS

[0133] Fresh avocados, of Chilean origin, Hass variety, have been supplied. The approximate size of the fruits is 200 g.

[0134] The firmness of avocados is assessed by measurement with a penetrometer. This measures the force required (in kg / cm²) to penetrate the fruit with a calibrated needle. Before measurement, the fruit is peeled to eliminate the resistance of the skin (seed). The shaft, also called the tip or nozzle, used for this measurement has a nominal diameter of approximately 8 mm. The hard avocados used had a penetration resistance into the flesh greater than or equal to 3 kg / cm². The soft avocados used had a penetration resistance less than or equal to 1 kg / cm². Avocados of medium firmness have an intermediate penetration resistance, ranging from 1 (not inclusive) to 3 kg / cm². b) DETAILED EXPERIMENTAL PROCEDURE b1) Comparison: Drying of fresh avocados by steaming (control) Control Trial Results (Table 9):

[0135] Table 9: Test Results - Control of Example 5 Drying time (h, min', sec") Drying temperature (°C) Humidity (relative percentage) % unsaponifiable (in oil) % sugar (in the press cake) 8h 80 4.2 8.0 11.3 b2) Invention: Microwave drying of fresh avocados on a pilot scale:

[0136] Approximately 550 g of fresh avocados are sliced ​​into 1-2 mm slices using an electric slicer and then immediately dried on the Extractor 200 unit under a hot airflow at 60°C. The microwave power is set between 800 and 1150 W. The microwave frequency is set to 2450 Hz.

[0137] In order to have trials on fruits of different maturity, the trials are carried out twice but one day apart, all other parameters being equivalent. Results (Table 10):

[0138] Table 10: Trial results according to avocado ripeness level Fruit resistance (Kg / cm²) Humidity (relative percentage) % unsaponifiable (in oil) % sugars (in the oilseed cake) Condition No. 1: 1000 W, 20 min drying ≥ 3 4.7 10.7 13.2 ≤ 1 3.8 9.3 9.7 Condition No. 2: 800 W, 27 min drying time ≥ 3 4.7 11.5 11.1 ≤ 1 3.9 10.8 9.5 Conclusions

[0139] Regardless of the microwave drying conditions, the unsaponifiable content of the oil is reduced when the avocados are more mature. The sugar content of the press cake is also decreased. Example 6: Avocado slice size a) LAWYERS

[0140] Fresh, firm avocados of Chilean origin, Hass variety, have been supplied. The approximate size of the fruits is 200g. b) DETAILED EXPERIMENTAL PROCEDURE b1) Comparison: Drying of fresh avocados by steaming (control) Results of the control test (Table 11) :

[0141] Table 11: Test Results - Control of Example 6 Drying time (h, min', sec") Drying temperature (°C) Humidity (relative percentage) % unsaponifiable (in oil) 8h 80 3.7 13.7 b2) Invention: Drying fresh avocados by microwave in continuous mode:

[0142] Between 300 and 600 g of fresh avocados are sliced ​​into 1-2 mm strips or cut into 1.5 cm cubes and then immediately dried in a microwave oven with a conveyor belt equipped with a microwave generator. The power is set to 3000 W, the frequency to 2450 Hz, and the airflow to 3000 L / min at 85°C. The drying time is similar for both trials (18'40'').

[0143] The various tests carried out made it possible to test the impact of the shape of the avocado pieces during microwave drying: Results (Table 12):

[0144] Table 12: Trial results according to avocado cutting Lawyer format Humidity (relative percentage) % Unsaponifiable (in oil) slices 2.7 13.9 cubes 10.1 10.5 Conclusions

[0145] Cutting avocados into cubes does not allow the fruit to dry completely, which has a negative impact on the quality of the drying and an alteration of the unsaponifiable content of the oil obtained. Example 7 : Format and cuts of avocado pieces a) LAWYERS

[0146] 16 Hass avocados, hard green, of Hass variety and of Peruvian origin, declared to belong to a single batch of fruit, are supplied on the morning of their implementation. b) DETAILED EXPERIMENTAL PROCEDURE

[0147] The avocados are dried using the GFMO 01 microwave oven.

[0148] For each test, 250 g of fruit are spread on the microwave oven tray. The number of tests is doubled. Each operating condition therefore requires 500 g, or approximately 2 avocados. A microwave power of 600 W is applied for 22 minutes for each test. The microwave oven is regularly ventilated to remove evaporated water, thus replicating the airflow present in the pilot tests.

[0149] The tests carried out on dried avocados to assess drying performance are: > Fruit color: Observing the fruit (appearance, color) allows us to assess the effectiveness of the drying process and the absence of material degradation. The color should be green to light brown. A dark brown to black color indicates carbonization of the fruit and therefore an alteration of the chemical integrity of the material (and thus a degradation of the desired active ingredients). ➢ Residual moisture: Measured using infrared technology (performed on the finely ground product), this ensures that the maximum threshold of 5% is reached (Expanscience specification).

[0150] Three drying tests were thus carried out: 1. 2 x 250g whole avocados, with skin and pit, sliced ​​into 3mm thick slices. The Figure 1 represents the samples from test 1 before drying ( Figure 1A ) and after drying ( Figure 1B 2. 2 x 250g of avocado, crushed and pitted (without skin or pit), sliced ​​in half. The Figure 2represents the external appearance of the samples from test 2 before drying ( Figure 2A ) and after drying ( Figure 2B ), and the core appearance of the samples from test 2 after drying ( Figure 2C 3. 250 g of peel + pit, sliced ​​into 3 mm thick strips. The Figure 3 represents the samples from test 3 before drying ( Figure 3A ) and after drying ( Figure 3B ). Results (Table 1213) :

[0151] Table 13: Trial results according to avocado cutting Trial 1 Test 2 Trial 3 Power (W) 600 600 600 Time (per lawyer) (min) 12 12 12 Appearance Correct, ideal and consistent Burnt throughout, not homogeneous Partially burned, not homogeneous Starting mass (g) 100 100 100 Mass after drying (g) 27.4 33.7 27.1 Humidity level (%) 2.27 4.9 0.86 Conclusions

[0152] When drying a peeled, pitted, and halved avocado (test 2), it is not possible to achieve the desired level of dryness without altering its composition. Indeed, the avocado chars throughout, but not on the surface. Therefore, the drying process is carried out by heterogeneous wayAs part of the drying process for sliced ​​skins and kernels, it It is not possible to reach the required level of drying of the avocado skin and pit without altering its composition. Partial carbonization of the pits is observed. The drying process therefore takes place in a heterogeneous manner.

[0153] These tests show that different parts of the avocado react differently to microwave drying under equivalent conditions. Unlike tests using isolated avocado parts (flesh or skin / pit), using a whole sliced ​​avocado results in consistent, even drying without any alteration to the material; this is true despite the presence of the three different parts of the avocado.

Claims

1. A process for preparing dehydrated avocados having a residual moisture content of less than or equal to 5%, said process comprising the following steps: a) selecting fresh avocados having a strength of penetration into the flesh greater than 1 kg / cm2, said strength being measured using a penetrometer ; b) slicing the selected whole avocados into strips; and c) drying the avocado strips obtained in step b) using microwaves until dehydrated avocados with a residual moisture content of less than or equal to 5% are obtained, during this step the water evaporated by the action of the microwaves being removed by means of a flow of hot air at a temperature of less than or equal to 80°C at a flow rate of greater than or equal to 150 m3 / h.

2. Process according to claim 1, characterised in that in step b), the whole avocados are sliced into strips 1 to 5 mm thick, advantageously 1 to 3 mm thick, in particular 2 mm thick.

3. Process according to claim 1 or 2, characterized in that during step c), the water evaporated under the action of microwaves is removed by means of a flow of hot air at a temperature of less than 80° C, advantageously at a temperature of between 40° C and 80°C, more advantageously at a temperature of between 40° C and 60° C.

4. Process according to any one of claims 1 to 3, characterised in that during step c), the hot air flow rate is between 180 and 500 m3 / h.

5. Process according to any one of claims 1 to 4, characterised in that in step c), the microwave power is between 1000 and 5000 W, preferably between 2000 and 5000 W, in particular between 2500 and 5000 W.

6. A process for preparing an unsaponifiable-rich avocado oil comprising the following steps: a) Selecting fresh avocados having a strength of penetration into the flesh greater than 1 kg / cm2, said strength being measured using a penetrometer; b) Slice the selected whole avocados into strips; c) Drying the avocado strips obtained in step b) using microwaves until dehydrated avocados with a residual moisture content of less than or equal to 5% are obtained, during which step the water evaporated by the action of the microwaves is eliminated using a flow of hot air at a temperature of less than or equal to 80°C at a flow rate of greater than or equal to 150 m3 / h ; d) Optionally, crushing the dehydrated avocados obtained in step c); e) Extraction of the oil from the dehydrated avocados obtained in step c) or d), preferably by mechanical pressing; and f) Recovery of the oil obtained, preferably by filtration.

7. A process for preparing an unsaponifiable avocado fraction comprising the following steps: - steps a) to f) as defined in claim 6, - a step g), alternatively : i. heat treatment of the extracted oil at a temperature advantageously between 80 and 150°C, followed by concentration of the oil into its unsaponifiable fraction, or else ii. concentration of the oil into its unsaponifiable fraction, followed by heat treatment at a temperature advantageously between 80 and 150°C, - followed by a step h) of saponification and extraction of the unsaponifiable matter, - and optionally a step i) of at least one purification and / or fractionation operation.

8. A process for preparing a sugar-rich avocado cake comprising the following steps: a) Selecting fresh avocados having a strength of penetration into the flesh greater than 1 kg / cm2, said strength being measured using a penetrometer; b) Slice the selected whole avocados into strips; c) Drying the avocado strips obtained in step b) using microwaves until dehydrated avocados with a residual moisture content of less than or equal to 5% are obtained, during which step the water evaporated by the action of the microwaves is eliminated using a flow of hot air at a temperature of less than or equal to 80°C at a flow rate of greater than or equal to 150 m3 / h; d) Optionally, crushing the dehydrated avocados obtained in step c); e) Extraction of the oil from the dehydrated avocados obtained in step c) or d), preferably by mechanical pressing; and f') Recovery of the cake obtained, preferably by filtering the oil extracted in step e).

9. Process according to any one of claims 6 to 8, characterised in that step e) of extracting the oil is carried out by mechanical pressing at a temperature of between 80 and 100°C.

10. Process according to claim 6 or 9, characterized in that the avocado oil obtained comprises an unsaponifiable matter content of at least 3%, more advantageously at least 5%, by mass of unsaponifiable matter, relative to the total mass of the oil.

11. Process according to claim 8 or 9, characterized in that the avocado cake obtained comprises a sugar content of at least 5% by weight, preferably from 5% to 15% by weight, relative to the total weight of the cake obtained.

12. Process according to claim 8, 9 or 11, characterized in that the avocado cake obtained comprises a protein content of at least 5%, in particular from 5% to 10%, more particularly from 6% to 10%, by weight relative to the total weight of the cake.