Innovative method for extracting natural, pure and stable lycopene

Abstract

The present invention discloses an innovative method for extracting natural lycopene from the peels of tomato by-products obtained from industrial processing. Said method involves a mild solid-liquid extraction based on the use of the ethanol-terpene green solvent which is highly selective with respect to lycopene. Said method being characterized in that it comprises the following steps: recovering the tomato peels, washing said peels so as to remove impurities therefrom, drying and grinding the purified peels, bringing the tomato peel powder into contact with the ethanol-terpene solvent, removing tomato peel residues, concentrating the lycopene extract and recycling the extraction solvent, drying said lycopene extract so as to remove traces of ethanol and obtain a pure terpene-enriched lycopene extract. Said lycopene extract is pure, stable, endowed with biological properties, and characterized by a high extraction yield of the order of 99%, intended for use in food, nutraceutical, pharmaceutical and cosmetic applications.

Description

Innovative process for extracting natural, pure and stable lycopene [1] TECHNICAL FIELD [2] The present invention relates to the technical field of extraction of natural substances and specifically relates to an ecological, efficient and selective process for extracting lycopene using the green ethano-terpene solvent. This process makes it possible to produce a pure and stable lycopene extract, intended for use in food, nutraceutical, pharmaceutical and cosmetic compositions. [3] OBJECTIVE OF THE INVENTION [4] The objective of the invention is to develop a selective, efficient and environmentally friendly extraction method to obtain a pure and stable lycopene extract from tomato. This solution is based on the use of a green ethano-terpene solvent, which has a high affinity and selectivity for lycopene, allowing complete extraction and easy recovery of pure and stable lycopene. [5] STATE OF THE ART [6] Carotenoids, a group of unsaturated hydrocarbons forming a family of isoprenoid pigments, are found in yellow, red, or orange fruits and vegetables, and can also be synthesized by photosynthetic organisms or some non-photosynthetic fungi and bacteria. They are divided into two chemical groups: carotenes and xanthophylls. Carotenes, characterized by pure hydrocarbons with the molecular formula C40H56 (such as β-carotene and lycopene), have an open-chain or cyclic structure. Xanthophylls, on the other hand, are oxygen-containing carotenoids (such as lutein). Carotenoids, in addition to their coloring power, are natural antioxidants that reduce free radicals, making them very interesting for the food, pharmaceutical, and cosmetic fields. [7] Lycopene is the most important carotenoid in terms of antioxidant activity. Due to its high capacity to inactivate singlet oxygen, lycopene plays a crucial role in strengthening the body's antioxidant defense system. Due to this property, lycopene is in high demand by the food and cosmetic industries. Its antioxidant activity is also exploited in the pharmaceutical field, particularly in the therapy of cardiovascular diseases and certain cancers (Giovannucci et al., J. Nat. Cancer Inst., 87: 1767-1776 (1995); Clinton et al., Nutr. Rev., 56: 35-51 (1998)). i [8] The human body cannot produce lycopene and must obtain it through diet, with tomatoes and tomato products being the richest source of lycopene (Tan., J. Food Soi., 53:954-959 (1988); Sadler et al., J. Food Soi., 55:1460-1461 (1990); Khachik et al., J. Agric. Food Chem., 40:390-398 (1992); Gartner et al., Am. J. Clin. Nutr., 66:116-122 (1997)). [9] The typical composition (mg / 100 g fresh weight) of carotenoids and polyphenols in ripe tomato fruits is well documented (Davies et al., Food Soi. Nutr., 15: 205-280 (1981); Martinez-Valverde et al., J. Sci. Food Agric., 82: 323-330 (2002); Galpaz et al., Plant Cell., 18: 1947-1960 (2006); Slimestad et al., J. Agric. Food Chem., 56: 2436-2441 (2008)).

[0010] Tomatoes have the highest concentration of lycopene in their peels, which contain almost five times more than the fruit itself. Tomato peels are therefore an excellent raw material for lycopene production.

[0011] The tomato processing industry generates large quantities of by-products, mainly tomato peels, which are an important source of lycopene and have attracted the attention of the natural extracts industry.

[0012] The patent review revealed numerous documents relating to the extraction of lycopene from tomatoes. Depending on the chemical structure of lycopene, the extraction solvent can be non-polar or moderately polar, with an affinity for lycopene.

[0013] Document US20100055261A describes a process for extracting lycopene from tomato peels using a solvent mixture comprising two or more components: a nonpolar or moderately polar solvent, a protic polar solvent, and an optional aprotic polar solvent. This mixture includes hexane or ethyl acetate, ethanol or water, and acetone. The advantages of this mixture are high extractive activity and fast extraction kinetics.

[0014] In practice, the choice of solvent is crucial to obtain a high-quality natural antioxidant. The ideal solvent must be non-toxic, environmentally friendly, and capable of increasing extraction yields.

[0015] However, extracting lycopene from tomatoes with organic solvents does not produce a high-quality product, and the purity of the final product is low. Lycopene, which is temperature-sensitive and photoactive, easily degrades and isomerizes during heating extraction.

[0016] The use of organic solvents is not ideal for environmental and product safety reasons, and reducing these solvents could improve extraction efficiency. EP3400812A1 proposes a method combining freezing, heating, water washing, and the use of ethanol, thereby reducing lycopene isomerization.

[0017] Document CA2480337A1 describes a process for extracting lycopene from whole tomato concentrate. The process uses water-saturated ethyl acetate, followed by backwashing with water and concentration of the extract under reduced pressure. The purity of the lycopene is then increased by filtration and drying. This process produces a whole tomato extract with a lycopene content of between 5 and 20%.

[0018] In CN1799674A, the extraction of lycopene from tomato peels by supercritical carbon dioxide, with ethanol as a co-solvent, showed good lycopene recovery (65-72%). Despite the non-polar structure and high molecular weight of lycopene, the addition of a polar modifier to supercritical CO2, such as ethanol, improves the extraction efficiency.

[0019] Ethanol is commonly used in lycopene extraction, but naturally abundant all-trans lycopene is poorly soluble in ethanol, making extraction inefficient. The ethanol extraction method disclosed in W02001038443A1 is simple, but the low solubility of lycopene in ethanol limits the extraction efficiency.

[0020] Lycopene extracted from tomatoes is generally crystalline, but its stability is compromised by oxidation during storage. Antioxidants are needed to prevent degradation.

[0021] Document CN103404844A describes a composition preparation method which can enhance the stability of lycopene by adopting the "film under vacuum / heat emulsification". Lycopene powder or granules, suitable plant extracts, emulsifying agent, emulsifying agent assistant and edible oil are thoroughly mixed, the emulsification treatment develops the evenly distributed compound of each main component. A suitable diluent, disintegrant and dry adhesives are added again, and the mixture is filled into a soft / hard shell capsule. The storage stability of the composition is much higher than that of current lycopene-containing products, but the process seems time-consuming and requires a lot of ingredients.

[0022] Oils contain natural antioxidants that can improve the stability of lycopene by delaying its oxidative degradation process. Vegetable oils such as olive oil (KR 102270447B1), squalane, safflower oil, camellia oil, macadamia nut oil, jojoba oil, sunflower oil, sesame oil, and avocado oil (KR 100692253B1) can be used as solvents to extract lycopene from tomatoes. However, it is difficult to separate the extracted lycopene from excipients, which are therefore necessarily incorporated as such into formulated products and can limit or modify the use of the extracted lycopene.

[0023] It is therefore necessary to develop a selective, efficient and environmentally friendly extraction method to obtain pure and stable lycopene from tomatoes.

[0024] The invention proposes a solution based on the use of a green ethano-terpene solvent, which has a high affinity and selectivity for lycopene, allowing complete extraction and easy recovery of pure and stable lycopene.

[0025] STATEMENT OF THE INVENTION

[0026] The present invention aims to provide an ecological, efficient and selective process for the extraction of natural lycopene from tomato peels originating from the industrial processing of tomatoes.

[0027] This objective is achieved by using a green ethano-terpenic solvent, selective for lycopene, and by adopting a solid-liquid extraction under mild conditions, allowing to obtain a natural, pure and stable lycopene extract with a high extraction yield of approximately 99%.

[0028] The solid-liquid extraction process of lycopene from tomato by-product peels includes the following steps: - Tomato by-products are recovered in the tomato processing industry according to a systematic procedure. The peels are separated from the seeds and then washed with water to remove impurities, thus obtaining a relatively pure raw material. The tomato peels are then subjected to a drying process until their moisture content is less than 10%. - Dried tomato peels are finely ground so that the particles are less than 0.5 mm. These peels are then macerated with the ethano-terpene extraction solvent. The interaction is carried out at a controlled temperature of 70°C for one hour, during which the ethano-terpene solvent effectively extracts the lycopene content present in the raw material. - The lycopene extract thus obtained is isolated from the residual solid phase of tomato peels. The isolation is carried out by a filtration method, using a suitable filter which completely removes all traces of tomato peels, leaving only the liquid phase of the lycopene extract. - The lycopene extract is concentrated by vacuum evaporation until it contains only 5 to 10% of the ethano-terpene solvent. Under mild conditions (heating to 70°C), this treatment allows the recovery of a concentrated lycopene extract and a significant amount of ethano-terpene solvent, which is reused in new extraction processes. - The recovered concentrated lycopene extract is carefully dried in the dark at room temperature overnight to remove any lingering traces of ethanol, which dissipates into the atmosphere, and to obtain a pure condensed lycopene extract that contains some of the terpenes.

[0029] BRIEF DESCRIPTION OF THE FIGURES

[0030] Other features and advantages of the invention will become more apparent in the detailed description which follows and refers to the following figures: Figure 1. Functional diagram of the lycopene extraction process according to the present invention. Figure 2. Chromatographic profile of lycopene extracted with the ethano-terpene solvent of peppermint. Figure 3. Chromatographic profile of lycopene extracted with the ethano-terpene solvent of thyme. Figure 4. Chromatographic profile of lycopene extracted with the ethano-terpene solvent of verbena. Figure 5. Chromatographic profile of lycopene extracted with the ethano-terpene solvent of rosemary. Figure 6. Chromatographic profile of lycopene extracted with the mixture of the four previous ethano-terpene solvents. Figure 7. Chromatographic depth of lycopene extracted with ethanol. Figure 8. Degradation of lycopene in different ethano-terpene solvents.

[0031] DETAILED DESCRIPTION OF THE INVENTION

[0032] The invention relates to an environmentally friendly, efficient and selective process for the extraction of lycopene from tomato by-product peels, characterized by the use of an ethano-terpene green solvent for solid-liquid extraction.

[0033] In a first embodiment, the tomato by-products may originate from the processing industry, such as in the production of tomato paste, such by-products being generally considered waste in the food industry.

[0034] In a preferred embodiment, the by-products comprise primarily tomato peels, representing about 40 to 80% of the wet by-product.

[0035] Tomato by-products contain tomato peels and seeds, with the majority of lycopene found in the peels. The process can be applied to by-products with or without seeds, after their separation.

[0036] It is often convenient to collect the peels from tomato by-products to remove seeds and impurities, thus increasing the yield and purity of the extraction.

[0037] The seeds can be removed manually, by gravity, sieving or with a deseeding machine.

[0038] In one embodiment, the recovered peels may be washed with water to remove impurities.

[0039] In a preferred embodiment, the tomato peels are free of seeds and impurities prior to extraction.

[0040] Optimal results can be achieved by homogenizing the recovered peels.

[0041] Tomato peels are selected based on their initial lycopene concentration.

[0042] The wet peels are dried to a moisture content of between 10 and 15% by weight, preferably between 7 and 10%.

[0043] Drying methods include freeze-drying, drum drying, tray drying, sun drying and spray drying.

[0044] In a preferred embodiment, the peels are dried at a temperature of 60°C or less, under ventilation, to preserve the lycopene.

[0045] Moisture content is determined by air drying at 105°C to constant weight, with samples of 0.5 to 1 g.

[0046] The dried peels are ground to increase their surface area for extraction.

[0047] After grinding, the peel powder, with particles of 0.01 to 0.5 mm, is used for the extraction of lycopene.

[0048] Preferably, for subsequent use of the tomato peel powder, it is desirable to vacuum pack it, to eliminate oxygen, in airtight plastic bags or other suitable containers and freeze it at a temperature of -20°C.

[0049] Before extraction, the peel powder is thawed at 4°C, away from light and air.

[0050] The method for extracting lycopene from tomato peels of the present invention avoids the use of unsafe solvents and offers the production of an environmentally friendly high purity lycopene extract, while providing a substantial improvement in the efficiency of lycopene extraction.

[0051] The extraction method described in this invention is based on the exploitation of the solubility of lycopene in the ethano-terpene solvent. The choice of the composition of ethano-terpene solvents for the extraction of lycopene from tomato peels is governed by a precise study of the molecular polarity of lycopene.

[0052] The carotenoid fraction in tomato peels consists of lutein, beta-carotene, Ç-carotene, ß-carotene, phytofluene, phytoene, and lycopene (Uchegbu et al., African J. Food, Agric. Nutr. Dev., 22: (2022)). The number and position of functional groups have a considerable influence on the polarity of carotenoid molecules (Ramakrishnan et al., J. Food Quai., 3: 25-34 (1980)). Carotenoids can be classified into classes of increasing polarity: phytoene, phytofluene, α-carotene, β-carotene, δ-carotene, δ-carotene, δ-carotene, lycopene, lutein (Meléndez-Martïnez et al., J. Food Compos. Anal., 20: 638-649 (2007)).

[0053] Selective extraction could be achieved by adjusting the degree of polarity of the extraction solvent. Due to the distinct solubilities of different types of carotenoids, the use of the moderately polar ethano-terpene solvent, in which lycopene is most soluble, allows selective extraction of lycopene without coextraction of highly apolar and intermediate polarity components.

[0054] The extraction solvent used in the process of the present invention is the terpene-rich plant-derived ethano-terpene solvent disclosed in our patent application filed under number MA61739. It is a natural green solvent of plant origin formed from a synergistic mixture of terpenes and ethanol.It is produced by a green process based on the recovery of terpene components from plants by solid-liquid extraction at low temperature, using ethanol as a GRAS solvent, said process being characterized in that it comprises the following steps: washing the plants with water; removing the wash water; grinding the plants; macerating the plant material with ethanol in a mass ratio of 1: 10 at a temperature of 50°C for one hour with stirring; removing the residues by filtration; decolorizing the extract by vacuum evaporation at a temperature of 90°C under a pressure between 0 and 900 bar to remove the plant pigments and obtain a transparent solvent rich in terpenes.

[0055] Ethano-terpene solvent is a clean solvent, free from residual impurities, suitable for sensitive applications such as food and pharmaceutical processing. It is an alternative to many conventional petroleum-derived solvents.

[0056] The present invention relates to a single-phase extraction process involving a systematic study of five distinct varieties of the ethano-terpene solvent.

[0057] The choice of the polarity of the terpene composition in the ethano-terpene solvent is an important criterion for selective extraction of lycopene.

[0058] In one embodiment, the five varieties of the ethano-terpene solvent are selected based on the polarity of their terpene composition, which confers on them an affinity for lycopene.

[0059] In one embodiment, the ethano-terpene solvent used is rich in menthol, characterized in that it comprises at least 35-60% menthol, a product of peppermint.

[0060] In one embodiment, the ethano-terpene solvent used is rich in thymol, characterized in that it comprises at least 10-64% thymol, a product of thyme.

[0061] In one embodiment, the ethano-terpene solvent used is rich in eucalyptol, characterized in that it comprises at least 15-55% eucalyptol, produced from rosemary.

[0062] In one embodiment, the ethano-terpene solvent used is rich in citral, characterized in that it comprises at least 14.8-45.5% of citral, a product of verbena.

[0063] In one embodiment, the ethano-terpene solvent used is a mixture of the four preceding ethano-terpene solvents.

[0064] In one embodiment, the ethano-terpene solvent used in the present invention is characterized by an ethanol purity equal to 99%.

[0065] Menthol is a cyclic monoterpene alcohol, characterized by a phenolic group. The presence of this phenolic group makes it slightly polar (Ejaz et al., Biol. Clin. Sci. Res. J., (2020)). Menthol is known for its various biological properties such as antimicrobial, anticancer, and anti-inflammatory activities (Brahmi et al., Aromatic and medicinal plants-Back to nature., 10: 47-79 (2017)).

[0066] Thymol is a non-polar monoterpene phenol (Aghamohammadi et al., P harm, biomed. res., 2: 8-13 (2016)). Numerous studies have suggested that the action of thymol is very potent, it has antimicrobial, antioxidant, antibacterial, antitussive, antispasmodic and expectorant actions (HÔferl et al., J. Essent. Oil Res., 21: 459-463 (2009)).

[0067] Eucalyptol is a cyclic monoterpene ether, it is very non-polar (da Cruz et al., J. Supercrit. Fluids, 31: 263-271 (2004)) and exhibits potent antibacterial and antiviral properties (Lesnik et al., Phytochem. Rev., 20: 1273-1328 (2021)).

[0068] Citral is a slightly polar acyclic monoterpene aldehyde (Qin et al., J. Mol. Liq., 350: 118524 ​​(2022)) and possesses various important therapeutic properties such as antioxidant, antimicrobial, anti-inflammatory, anticancer, and antidiabetic properties (Sharma et al., Med Chem., 17: 2-12 (2021)).

[0069] In one embodiment, the lycopene extraction process according to the present invention is carried out in a solid / liquid ratio of between 1 and 5% (mass per volume). The reaction mixture is maintained for a period of 40 minutes to 2 hours at a temperature of between 40 and 80°C, with magnetic stirring at a speed of 400 to 600 rpm.

[0070] In a preferred embodiment, the extraction of lycopene by the ethano-terpene solvent is a maceration carried out under magnetic stirring for one hour at 400 rpm at a temperature of 70°C with a solid-liquid ratio of 3.5%.

[0071] The extraction mixture is preferably subjected to magnetic stirring. This improves the penetration of the ethano-terpene solvent into the tomato peel tissues and accelerates the release of lycopene into the solvent by disrupting the cell walls.

[0072] Advantageously, the extraction is carried out in reduced light or in the dark, in order to avoid photo-degradation of lycopene.

[0073] The isolation of lycopene extract from the extraction reaction mixture is carried out using conventional separation techniques, which are part of the general knowledge in the field and which can be found in the relevant literature.

[0074] The solid-liquid separation technique is advantageously carried out by filtration. Preferably, it is a cellulose filter with a pore size less than or equal to 2 μm.

[0075] In a preferred embodiment, the lycopene extract is subjected to a concentration step by vacuum evaporation until it contains only 5 to 10% of the ethano-terpene solvent.

[0076] Vacuum evaporation is preferably carried out under rotation at a temperature of 70°C and at a pressure between 0 and 900 bar.

[0077] According to an advantage of the present invention, the process allows a recovery of more than 90% of the ethano-terpene solvent, thanks to its volatile nature, which is reusable for several new extraction cycles without the formation of oxidation compounds.

[0078] The recovered concentrated lycopene extract is carefully dried in the dark at room temperature overnight to remove any lingering traces of ethanol, which dissipates into the atmosphere.

[0079] The final product resulting from the process of the present invention is a pure extract of condensed lycopene which is enriched in terpenes.

[0080] The concentration of lycopene in the extracts was measured by HPLC-DAD at a wavelength range of 450-500 nm.

[0081] HPLC analysis was also used to evaluate the selectivity of the ethano-terpene solvent towards lycopene extracted from tomato by-product peels.

[0082] In one embodiment, an HPLC-DAD method based on isocratic elution was developed for the analysis and quantification of lycopene in tomato peel extracts. Identification of individual lycopene in the extracts was performed by comparing the absorption depth and retention time with the depth of the chromatogram of the authentic standard.

[0083] Comparison with the spectra of pure lycopene clearly reveals that the pigment extracted from tomato peels contains mainly said lycopene.

[0084] To determine the selectivity of the lycopene extraction process of the present invention, the chromatograms of the extracts were compared with those of the analytical standard, in order to reveal the absence of other components and impurities in the extract.

[0085] In the lycopene extraction process of the present invention, the use of the ethano-terpene solvent is an original, environmentally friendly approach that gives better results in terms of qualitative and quantitative determination.

[0086] The process of the present invention is considered an interesting alternative to conventional organic solvents, whose toxicity to humans and the environment is considerably reduced.

[0087] The process of the present invention is clean, selective and efficient for the production of high quality natural lycopene extracts, free from residual impurities of organic solvents.

[0088] The lycopene extraction process of the present invention is carried out under mild conditions, thus protecting the lycopene molecule from thermal degradation and oxidation.

[0089] The ethano-terpene solvent applied in the process of the present invention has the advantage of being highly selective for lycopene and having a high extraction power. Its use makes it possible to extract only lycopene, to improve the extraction kinetics and to obtain high extraction yields of the order of 99%.

[0090] Advantageously, terpenes are known for their stability and their antioxidant, anti-inflammatory and antimicrobial properties, and their presence in significant quantities in the pure lycopene extracts according to the invention increases the stability of lycopene against the phenomenon of oxidation and degradation during storage and its effectiveness in food, nutraceutical, pharmaceutical and cosmetic uses.

[0091] The product of this invention serves as a source of pure and stable lycopene for incorporation into diets or beverages or as a nutritional supplement for human consumption, for the pharmaceutical and cosmetic industries and for the ingredient industries as a suitable and effective food additive and colorant.

[0092] METHOD OF IMPLEMENTATION

[0093] According to a general concept of the invention, lycopene is extracted from tomato by-product peels using the green ethano-terpene solvent according to the following steps - Recovery of tomato peels from by-products of industrial tomato processing; - Washing the said tomato peels in water, then drying them until their humidity level is less than 10%; - Grinding of dried tomato peels to a particle size of less than 0.5 mm; - Maceration of tomato peel powder with ethano-terpene solvent in a solid-liquid ratio of 3.5%; - Separation of lycopene extract from the solid phase of tomato peel powder; - Concentration of the lycopene extract by vacuum evaporation until it contains only 5 to 10% of the ethano-terpene solvent and recovery of said solvent; - Drying of the recovered concentrated lycopene extract to remove any lingering traces of ethanol and obtain a pure condensed lycopene extract containing some of the terpenes.

[0094] According to a first aspect of the invention, lycopene is extracted from high-quality tomato peels, free from seeds and impurities.

[0095] Preferably, drying of tomato peels is done in a convection oven equipped with a ventilation system at a temperature not exceeding 60°C.

[0096] According to a particular aspect of the invention, the ethano-terpene solvent used for the extraction of lycopene is rich in terpene compounds having a strong affinity for lycopene.

[0097] According to a particular aspect of the invention, the contacting of the tomato peel powder with the ethano-terpene solvent is carried out in the dark and under mild conditions, in order to avoid the degradation of the lycopene molecule during the process.

[0098] According to a second aspect of the invention, the lycopene extract from the separation step undergoes a concentration step by vacuum evaporation. Said step is carried out at a temperature of at least 70°C in a rotary evaporator. At the end of this step, a concentrated lycopene extract is recovered, with an extraction yield of around 99%.

[0099] According to a particular aspect of the invention, the concentrated lycopene extract is dried overnight at room temperature.

[0100] The lycopene extract obtained by the process of the invention is pure and enriched in terpenes, which gives the lycopene molecule great stability and biological properties allowing it to be used in food, nutraceutical, pharmaceutical and cosmetic applications.

[0101] EXAMPLES

[0102] Example 1: Preparation of lycopene extract

[0103] Extraction of lycopene by ethano-terpene solvent.

[0104] The ethano-terpene solvents studied for the selective extraction of lycopene from tomato by-product peels are: peppermint ethano-terpene solvent, rosemary ethano-terpene solvent, thyme ethano-terpene solvent, verbena ethano-terpene solvent and a mixture of the four previous ethano-terpene solvents.

[0105] Tomato peels (7% moisture) were ground to obtain particles with a size less than 0.5 mm. A weighed quantity of 50 g of the tomato peel powder was subjected to the process of lycopene extraction by the ethano-terpene solvent in a solid-liquid ratio of 3.5%, under magnetic stirring at 400 rpm for 1 h at 70 °C. Lycopene extraction from tomato peels was carried out in glass beakers. The beakers were placed on a magnetic stirrer in a thermostatic bath. To minimize the degradation of lycopene induced by light exposure, the experiments were carried out under reduced light conditions. For the same reason, all the light-exposed faces of the thermostatic bath container were covered with an opaque material.

[0106] During the maceration step, it is not necessary to renew the ethano-terpene solvent because it almost completely depletes the lycopene; a single extraction step is sufficient.

[0107] After stirring, the residue is removed by filtration through a 2 µm cellulose filter to obtain a very strongly red colored solution, from which 90% of the ethano-terpene solvent is then removed by vacuum evaporation. The entire system is placed under vacuum (0-900 bar) at a temperature of 70°C with rotation to facilitate solvent evaporation. The ethano-terpene solvent is vaporized and recycled, using the condenser, for further extraction operations, while the lycopene extract, with 10% of the ethano-terpene solvent, is recovered in the tank.

[0108] The resulting lycopene extract is left to dry overnight at room temperature to remove traces of ethanol.

[0109] Extraction of lycopene by ethanol

[0110] For comparison, ethanol is used as the extraction solvent. Otherwise, the parameters are the same as for lycopene extraction with ethano-terpene solvent.

[0111] Example 2: Quantitative and qualitative analysis of lycopene extracts

[0112] Identification and quantification of lycopene by HPLC-DAD

[0113] Lycopene extract from tomato peels is dissolved in methanol and used for the determination of lycopene content by HPLC-DAD using a Cl 8 column.

[0114] Each sample was shaken vigorously for 20 seconds to make the samples homogeneous. Methanol (0.9 mL) was aliquoted with 0.1 mL of each sample. The aliquots were filtered through 0.2 µm cellulose syringe filters and the filtrates were stored in HPLC vials as the final solution.

[0115] The analysis of lycopene extracted from tomato peels was performed with an HPLC system with photodiode detector using a C18 column (4.6 x 250 mm, 3 μm), and maintained at a temperature of 30°C. The mobile phase, a mixture of solvents: methanol and acetonitrile (70:30%, v / v) was used under isocratic conditions at 1 mL / min. UV-vis spectra were collected from 450 to 500 nm. Retention times and spectra were compared to the lycopene standard.

[0116] The calibration curves are constructed with lycopene and are calculated as lycopene equivalents at 472 nm in mg / 100 g of dry matter. The extraction yields of lycopene with the different ethano-terpene solvents according to the invention are as follows: - Lycopene extract by ethano-terpene solvent of peppermint analyzed by HPLC contains 96.91% lycopene. - Lycopene extract by ethano-terpene solvent of thyme analyzed by HPLC contains 80.35% lycopene. - Lycopene extract by ethano-terpene solvent of verbena analyzed by HPLC contains 83.69% lycopene. - Lycopene extract by ethano-terpene solvent of rosemary analyzed by HPLC contains 99.82% lycopene. - Lycopene extract from the mixture of four ethano-terpene solvents analyzed by HPLC contains 99.73% lycopene. - Lycopene extract by ethanol analyzed by HPLC contains 38.24% lycopene.

[0117] Figures 2 to 7 illustrate the chromatographic profile of lycopene extracted by ethano-terpene solvents, their mixture and by ethanol alone. The affinity and selectivity of the ethano-terpene solvent for lycopene are indeed observed, allowing an efficient extraction of the order of 80% to more than 99%. In comparison with an ethanol extraction which does not exceed 40%.

[0118] The extraction yields obtained by ethano-terpene solvents are much better than those obtained by ethanol alone. However, extraction by ethano-terpene solvent from rosemary showed the highest yield (99.82%) due to the very high affinity of eucalyptol for lycopene. Other ethano-terpene solvents from peppermint, verbena and thyme also show significant potential, with yields above 80%.

[0119] Stability test

[0120] The stability assessment of concentrated lycopene extracts was carried out by prolonged storage of these extracts, obtained by the ethano-terpene solvent extraction process, under controlled conditions at 4°C for a period of 12 months. The samples were analyzed by the HPLC-DAD method every four months of the incubation period.

[0121] Figure 9 illustrates the degradation profile of lycopene extracted by the five ethano-terpene solvents. The results show that the terpenes present in the extracts significantly improve the stability of lycopene with a low degradation of approximately 9%. The extract from the mixture of the four ethano-terpene solvents showed the best stability compared to the other extracts, thanks to the synergy of all the terpenes present in the extract. References cited in the description Aghamohammadi, A., Azadbakht, M., & Hosseinimehr, S. J. (2016). Quantification of thymol content in different extracts of Zataria multiflora by HPLC method. Pharmaceutical and Biomedical Research, 2(1), 8-13. Brahmi, F., Khodir, M., Mohamed, C., & Pierre, D. (2017). Chemical composition and biological activities of Mentha species. Aromatic and medicinal plants-Back to nature, 10, 47-79. Clinton, S. K. (1998). Lycopene: chemistry, biology, and implications for human health and disease. Nutrition reviews, 56(2), 35-51. da Cruz Francisco, J., Topgaard, D., Sivik, B., & Bergenstâhl, B. (2004). Phase behavior of the monoolein-water system: The effects of addition of the hydrocarbon 1, 8 -cineole and supercritical carbon dioxide. The Journal of Supercritical Fluids, 31(3), 263-271. Davies, J. N., Hobson, G. E., & McGlasson, W. B. (1981). The constituents of tomato fruit — the influence of environment, nutrition, and genotype. Critical Reviews in Food Science & Nutrition, 15(3), 205-280. Ejaz, R., Malik, S., Ahmad, M., Ali, H., & Choudhry, S. (2020). Anti-biofilm potential of menthol purified from Mentha piperita L. (Mint). Biological and Clinical Sciences Research Journal, 2020(1). Galpaz, N., Ronen, G., Khalfa, Z., Zamir, D., & Hirschberg, J. (2006). A chromoplast-specific carotenoid biosynthesis pathway is revealed by cloning of the tomato white -flower locus. The Plant Cell, 18(8), 1947-1960. Gartner, C., Stahl, W., & Sies, H. (1997). Lycopene is more bioavailable from tomato paste than from fresh tomatoes. The American journal of clinical nutrition, 66(1), 116-122. Giovannucci, E., Ascherio, A., Rimm, E. B., Stampfer, M. J., Colditz, G. A., & Willett, W. C. (1995). Intake of carotenoids and retino in relation to risk of prostate cancer. JNCI Journal of the National Cancer Institute, 87(23), 1767-1776. HÔferl M, Buchbauer G, Jirovetz L, Schmidt E, Stoyanova A, Denkova Z, Slavchev A, Geissler M (2009). Correlation of antimicrobial activities of various essential oils and their main aromatic volatile constituents. J. Essent. Oil Res.21:459-463. Khachik, F., Goli, M. B., Beecher, G. R., Holden, J., Lusby, W. R., Tenorio, M. D., & Barrera, M. R. (1992). Effect of food preparation on qualitative and quantitative distribution of major carotenoid constituents of tomatoes and several green vegetables. Journal of Agricultural and Food Chemistry, 40(3), 390-398. Lesnik, S., Furlan, V., & Bren, U. (2021). Rosemary (Rosmarinus officinalis L.): extraction techniques, analytical methods and health-promoting biological effects. Phytochemistry Reviews, 20(6), 1273- 1328. Martinez- Valverde, I., Periago, M. J., Provan, G., & Chesson, A. (2002). Phenolic compounds, lycopene and antioxidant activity in commercial varieties of tomato (Lycopersicum esculentum). Journal of the Science of Food and Agriculture, 82(3), 323-330. Meléndez-Martinez, A. J., Vicario, I. M., & Heredia, F. J. (2007). Analysis of carotenoids in orange juice. Journal of Food Composition and Analysis, 20(7), 638-649. Qin, Z., Cheng, H., Song, Z., Ji, L., Chen, L., & Qi, Z. (2022). Selection of deep eutectic solvents for extractive deterpenation of lemon essential oil. Journal of Molecular Liquids, 350, 118524. Ramakrishnan, T. V., & Francis, F. J. (1980). Autoxidation of carotenoids and their relative polarity. Journal of Food Quality, 3(1), 25-34. Sadler, G., Davis, J., & Dezman, D. (1990). Rapid extraction of lycopene and - carotene from reconstituted tomato paste and pink grapefruit homogenates. Journal of food science, 55(5), 1460-1461. Sharma, S., Habib, S., Sahu, D., & Gupta, J. (2021). Chemical Properties and Therapeutic Potential of Citral, a Monoterpene Isolated from Lemongrass. Medicinal chemistry (Shariqah (United Arab Emirates)), 17(1), 2-12. Slimestad, R., Fossen, T., & Verheul, M. J. (2008). The flavonoids of tomatoes. Journal of Agricultural and Food Chemistry, 56(7), 2436-2441. Tan, B. (1988). Analytical and preparative chromatography of tomato paste carotenoids. Journal of Food Science, 53(3), 954-959. Uchegbu, N. N., Ude, C. N., Obeta, N. A., & Eze, C. R. (2022). Characterization and optimization of carotenoid extracted from the peels of tomato Lycopersicon esculentum grown in Nigeria. African Journal of Food, Agriculture, Nutrition & Development, 22(1).

Claims

Claims 1. Process for the ecological, efficient and selective extraction of lycopene from the peels of tomato by-products from industrial tomato processing, by the use of the green ethano-terpene solvent, characterized in that it comprises the following steps: Recovery of tomato peels from by-products of industrial tomato processing; Washing the said tomato peels in water, then drying them until their humidity level is less than 10%; Grinding dried tomato peels to a particle size of less than 0.5 mm; Maceration of tomato peel powder with ethano-terpene solvent in a solid-liquid ratio of 3.5%; Separation of lycopene extract and solid phase from tomato peel powder 9 Concentration of the lycopene extract by vacuum evaporation until it contains only 5 to 10% of the ethano-terpene solvent and recovery of said solvent; Drying the recovered concentrated lycopene extract to remove any lingering traces of ethanol and obtain a pure condensed lycopene extract containing some of the terpenes.

2. Process for extracting lycopene according to claim 1, characterized in that the recovered tomato peels must be free from seeds and impurities.

3. Process for extracting lycopene according to claims 1 and 2, characterized in that the drying of the tomato peels is carried out in a convection oven equipped with a ventilation system at a temperature not exceeding 60°C.

4. Process for extracting lycopene according to claims 1 to 3, characterized in that the extraction solvent is the green ethano-terpene solvent rich in terpenes having an affinity and selectivity for lycopene.

5. Process for extracting lycopene according to claims 1 to 4, characterized in that the extraction solvent is chosen from the following group of solvents: ethano-terpene solvent from rosemary, ethano-terpene solvent from mint, ethano-terpene solvent from thyme, ethano-terpene solvent of verbena, mixture of the four previous ethano-terpene solvents.

6. Process for extracting lycopene according to claims 1 to 5, characterized in that the extraction solvent is preferably the ethano-terpene solvent of rosemary rich in eucalyptol.

7. Process for extracting lycopene according to claims 1 to 6, characterized in that the solid-liquid extraction of lycopene is carried out in the dark at a temperature of 70°C for one hour with magnetic stirring at 400 rpm.

8. Process for extracting lycopene according to claims 1 to 7, characterized in that the concentration of the lycopene extract is carried out by evaporation under vacuum at a temperature of 70°C and a pressure of between 0 and 900 bar.

9. Process for extracting lycopene according to claims 1 to 8, characterized in that the concentration of the lycopene extract makes it possible to recover more than 90% of the ethano-terpene solvent, which is reused in new extraction cycles without the formation of oxidation compounds.

10. A process for extracting lycopene according to claims 1 to 9, characterized in that the concentrated lycopene extract is dried in the dark at room temperature overnight to remove any persistent traces of ethanol.

11. Pure and stable natural lycopene extract produced by the ethano-terpene green solvent extraction process according to the preceding claims, characterized in that it comprises between 50 and 98% lycopene, preferably between 80 and 93% lycopene, and between 1 and 50% terpenes, preferably between 5 and 20% terpenes.

12. Use of the pure and stable natural lycopene extract according to claim 11, in food, nutraceutical, pharmaceutical and cosmetic applications.

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