DK169557B1 - Process for the production of fats - Google Patents

Abstract

1. A process for preparation of a fatty substance from pips of fruits of the Ribes genus, characterized by the following steps : a) washing the pips with a polar solvent or a supercritical fluid in a polar condition, b) treating the pips with an antioxidant in order to protect the oil contained therein against oxidation, c) forming the protected pips into flakes, d) pressing the flakes and collecting the oil, e) extracting the rest of the oil from the press cake with a non-polar solvent or a supercritical fluid in a slightly polar condition and the removing the solvent or the supercritical fluid.

Description

DK 169557 B1

The invention relates to a process for producing fats from fruits of the Ribes genus.

Most vegetable oils contain polyunsaturated linoleic (i.e., 6,9-octadiene) - and α-linolenic (i.e.

5 9,12,15-octadecatriene fatty acids. Only oils of hop species (Humulus), hemp (Cannabis), borago (Borage) and night light (Oenothera) are known to contain the γ-linoleic acid (ie 6,9,12-octadecatriene) acid, of which the only night light is available source and even at 10 high prices.

γ-Linolenic acid is an essential fatty acid which is metabolized by the organism to prostaglandins via dihomo-γ-linolenic acid and arachidonic acid (5,8,11,14-eicosatetraenoic acid), which itself is a constituent in cell membranes, while α linolenic acid does not similarly participate in this metabolism process. The linoleic acid conversion to γ-linolenic acid in tissues is incomplete (4-20% compared to 90-98% for the conversion of γ-linolenic acid to arachidonic acid) and may be completely absent (e.g. in cats) in the absence or inactivation of the enzyme Δ-6 desaturase.

A lack of essential fatty acids affects all of the metabolic processes mentioned above, which can result in biochemical diseases or organic damage (e.g., coagulation disorders, dermatological damage, endocrine disorders, myocardial damage and hepatic, articular disease). neurological and mental disorders). Therefore, it is possible to see the benefits obtained by the administration of γ-linolenic acid for the prevention or treatment of these anomalies.

For example, the possibility of using γ-linolenic acid and arachidonic acid as therapeutic agents is numbered in French Patents Nos. 2,197,605 and 1,603,383, with γ-linolenic acid being of synthetic origin or extracted from the oil of seeds of night light (Oenothera). or officinal borago (Borage of-35 ficinalis).

Furthermore, French Patent 2,255,055 DK 169557 B1 relates to cosmetic and pharmaceutical compositions based on the oil from raspberry kernels, whose anti-inflammatory activity is mentioned, but without mention of the composition. Since the oil is preferably extracted using chloroform (a polar solvent), the anti-inflammatory activity is probably due to the presence of smaller components. Furthermore, analysis of said oil has shown that it contained approx. 54% by weight of linoleic acid and 30% of an α-linolenic acid, but did not contain any γ-ϋ-10 nolenic acid.

Finally, Hungarian patent specification T 13226 states that the addition of a pulp or crude oil extracted from paprika, tomato or rib kernels to cosmetic products will prevent their oxidation. The extraction as described does not allow the separation of the undesirable waxes and dyes in the present products, and the composition of the extract is not discussed.

Surprisingly, it has now been found that oils from 20 grains from fruit of the Ribes genus have a significant percentage content, at least 4% by weight, of γ-linolenic acid. Furthermore, these grains are available in large quantities in the cakes resulting from juicing, from the preparation of boiled fruit and jelly or from the fermentation musts derived from the manufacture of brandy products, liqueurs and snaps, which have been used so far such as fuel or feed.

According to the invention, the fats are in practice derived from black currants (Ribes nigrum), ribs (Ribes rubrum), gooseberry (Ribes ovacrispa or grossularia) or from hybrid fruits of these species. A mixture of these fruits can also be used.

The lipid content of the above by-products ranges from 12 to 30% by weight depending on the starting material. The lipid phase, for its part, contains from 4 to 19% by weight of γ-linolenic acid.

It may be mentioned that the oil from the kernels of these fruits contains triglycerides of the following fatty acids, by weight:

Fatty Acid Black currant Ribbed Gooseberry C 16: 0 6-7% 4 - 5% 7-8% 5 C 18: 0 1-2% 1 - 2% 1-1% C 18: 1 cis 9 - 10% 14 - 15% 15 - 16% C 18: 1 trans 0.5% 0.5 - 1% 1- 2% C 18: 2ω6 47 - 49% 41 - 42% 39 - 41% C 18: 3ω6 15 - 19% 4 - 5 % 10 - 12% 10 C 18: 3 <i> 3 12 - 14% 29 - 31% 19 - 20% C 18: 4ω3 3 - 4% 2.5 - 3.5% 4 - 5%

Blackcurrant oil, which is preferred because of its high content of γ-linolenic acid, also contains from 1 to 2 15% by weight of non-saponifiable substances such as aliphatic alcohols, hydrocarbons, tocopherols, squalene, β-sitoste role, campesterol and Δ-7 -stigmasterol. Its density is 0.9215 g / cm 3 (at 20 ° C) and its viscosity is 28.3 centipoise (at 20 ° C).

The present invention relates to a process for the production of fats from grains from fruit of the Ribes genus, characterized in that it comprises a) washing the grains with a polar solvent 25 or a supercritical liquid in a polar state; b) treating the cores with an antioxidant to protect the diene contained therein against oxidation, c) converting the protected cores into flakes, d) pressing the flakes and collecting the diene, e) extracting the rest of the oil in the press cake with a non-polar solvent or supercritical liquid in a weak polar state, and removal of the solvent or supercritical fluid.

For purposes of the present invention, the term "vegetable material" used is intended to denote the by-products referred to above. The starting material is generally in the form of highly colored cakes containing the cores associated with the cores, waxes and dyes representing from 5 to 7% by weight of the crude oil which would be extracted therefrom, for example using hexane. The wax species are saturated and monounsaturated esters of long chain fatty acids with fatty alcohols which are solid at room temperature.

A preferred starting material is the cake obtained by pressing fruit juices, especially blackcurrant juice.

The cake is initially dried, e.g. in atmospheric air for approx. 1 hour at approx. 60 ° C. It is coarsely ground and sieved to obtain particles of 1 to 1.5 mm, the sieve yield being from 60 to 80% by weight of the cakes.

It is advantageous to separate the nuclei from the rest by gravity in a stream of atmospheric air or by elutriation with a weight yield of 80 to 15 90%.

According to a preferred embodiment of the present process, the cores are washed with a conventional polar solvent to liberate them from waxes, dyes and free fatty acids. For cosmetic applications, it is possible to use, for example, methanol, isopropanol, acetone, ethanol or a mixture of these solvents, or a supercritical fluid mixture, for example carbon dioxide under conditions which impart it to a polar character.

For pharmaceutical use, a solvent for example ethanol or supercritical carbon dioxide will be used.

Washing is performed, for example, by extracting the cores with ethanol under reflux, either portionwise, e.g. first for 2 hours and then for 30 - 60 minutes, or continuously for approx. 2 hours, then drain the rest.

According to a variant, it is possible to extract the cores using, for example, carbon dioxide at 35 250-350 bar (25-35 MPa) and at 60-80 ° C for a continuous cycle, the solvent being recovered in the gaseous state by lowering the pressure. after which it is recompressed and recycled. It has been found that extraction enables the removal of most of the staining materials and of the wax species in the obstacles and around the cores. The wax species are in fact precipitated from the alcoholic extract upon cooling, whereas the alcoholic extract 5 is very strongly colored.

A variant for the separation and purification of grains from the fruit juice press cakes involves treating the cakes enzymatically, for example, with an aqueous solution containing 0.01-0.5 wt.% Cellulase at a pH of 10 to 4-5 at a temperature of 38-42. ° C for 1-4 hours or at room temperature for 12-15 hours. The kernels can be easily separated from the crop, and both waxes and dyes are at least partially eliminated in this way.

Regardless of the variant used to obtain the cores, it is advantageous to treat the washed and drained cores with an antioxidant. This treatment protects the oil contained therein from subsequent oxidation oxidation. Suitable antioxidants include, for example, aqueous dilute solutions of ascorbine-20 or benzoic acid or sodium or potassium salts of these acids or combinations thereof, with ascorbic acid being preferred, for example, as an aqueous solution containing 30-50 ppm (parts per million) by weight of ascorbic acid representing 7-8% by weight of the cores.

The protected cores containing the antioxidant can then be pressed, for example, in a continuous screw press at high pressure. Depending on the type of press used, the number of press cycles and the press conditions used, up to 90% of the oil can be recovered.

A preferred variant for this step involves splitting the protected cores into flakes and pressing the flakes prior to solvent extraction. The protected cores are dried and flaked on a grinding cylinder from the non-milled, drained residue. This embodiment prevents clumping and facilitates subsequent extraction of the oil by imparting a porosity to the product which permits good penetration of the solvent, and in particular resists the flaking crushing. The flakes are then preheated at a temperature of 80-90 ° C and pressed at a pressure of 49-78.5 Pa, keeping the press head temperature below 90 ° C. In this way, 5 50-60% of the oil contained in the cores is recovered. The resulting press cake has a density of 0.58-0.65 g / cm 3, approx. twice the weight of the flags. This is recommended for good percolation of the solvent. The press cake is then ground and subjected to solvent extraction.

The next step involves extracting the oil with a non-polar solvent, e.g. hexane, in an amount of 200-250% by weight of hexane relative to the residue. According to a variant, in this step, 15 liquid carbon dioxide or preferably supercritical carbon dioxide can be used under conditions where it is slightly polar, for example at 200-300 bar (20-30 MPa) and at 40-60 ° C. Of course, it is also possible, for example, to use supercritical carbon dioxide in the washing step and in the subsequent extraction step or in only one of these steps, while the other is carried out using, for example, ethanol or hexane.

The pressed oil and the extracted solution are collected.

After extraction, it is possible, but only as preferred options, to neutralize the solution to remove the remaining free fatty acids after the solvent is partially evaporated, for example in the case of hexane, so that the solution contains approx. 10% by weight of oil using (2N) concentrated potassium or sodium hydroxide to cool the solution to 0-4 ° C for approx. 24 hours and filter it at this temperature to completely remove the remaining waxes. The subsequent decolorization and deodorization operations are also preferred features. Thus, the solution is decolorized using 2-8% by weight of an adsorbent, e.g. activated carbon or activated aluminum silicate, such as bentonite or montmorrilonite, based on the treated oil, at 20-60 ° C, after which the hexane is evaporated. The oil is then deodorized by steam vapor stripping at 140-220 ° C and preferably at ca. 180 ° C in a vacuum equal to or less than 1 torr (133 Pa).

According to a variant for the preparation of the oil, the ground cores are not first washed, but extracted directly with a solvent. In this case, the neutralization, removal of the waxes by decantation, decolorization and deodorization, as indicated above, are essential for the preparation of a pale yellow refined oil.

In some cases, a fat must be enriched with γ-linolenic acid. For this purpose, the oil liberated from waxes and free fatty acids is saponified with an alkali hydroxide, for example potassium hydroxide, in a medium of methanol / water at a concentration of approx. 11%, the resulting salts are acidified using a mineral acid, for example 2N sulfuric acid, the free fatty acids are extracted with hexane, and the organic phase is separated and dried, for example by the addition of sodium sulfate.

According to a variant, it is possible to directly treat the ground cake with an alkali hydroxide, acidify it using a mineral acid, extract the free fatty acids with hexane and dry the organic phase as stated above. The organic phase is fractionated by high-pressure liquid phase chromatography, by passing over silica gel columns loaded with silver nitrate and eluting preferably with a mixture of dichloromethane, toluene and diethyl ether 70: 25: 5-65: 30: 5 in an isocratic way, i.e.

30 with recirculation of the solvent composition of a fixed composition, thereby obtaining a fraction containing ca. 60% by weight of γ-linolenic acid and approx. 40% α-linolenic acid.

Practically pure γ-linolenic acid can be isolated by high-pressure liquid phase chromatography with a Cg or reverse phase carrier with a gradient of a solvent mixture of acetonitrile / water, methanol / water or iso-propanol / water.

DK 169557 B1 8

The process according to the invention is further described by the following example. In this example, parts and percentages are based on weight.

Example 432 kg Dried blackcurrant pulp resulting from juice pressing was ground in a disc mill and the milled product was sieved to yield 261 kg of 1-1.5 mm particles. The product was introduced into an elutriator, and 214 kg of a heavy fraction containing mainly nuclei were obtained. The fraction was washed twice with 520 kg of ethanol at reflux each time.

The 200 kg ethanol-washed blackcurrant cores obtained were sprayed with 14-16 liters of water containing 30-50 15 ppm (parts per million) of ascorbic acid. The treated cores were dried at ca. 70 ° C for 30-40 minutes and then flake. The flakes were then heated in a shaker at 80-90 ° C for 30-40 minutes. Their density was approx.

0.35 g / cm 3. The flakes were pressed for 30-50 minutes in a 20 continuous screw press at a pressure of 500-800 kg / cm 2, at a rotational speed of the screw of 10-20 rpm, keeping the press head temperature at 80-90 ° C. Under these conditions, 26-31 kg of oil (about 50-60% of the total oil contained in the kernels) was obtained. The press cake had a density of approx. 0.60 g / cm 3, which is suitable for the percolation of the solvent during subsequent solvent extraction. It was then ground and subjected to two hexane extractions as above, with refluxing 370-400 kg for 3 hours, then cooled and filtered. The hexane was then evaporated and 22-26 kg of additional oil was obtained.

Claims (10)

A process for the production of fat from kernels from fruits of the Ribes genus, characterized in that it comprises: a) washing the kernels with a polar solvent 5 or a supercritical liquid in a polar state, b) treating the kernels with an antioxidant c) converting the protected cores into flakes, d) pressing the flakes and collecting the diene, e) extracting the rest of the oil in the press cake with a non-polar solvent or a supercritical liquid in a slightly polar state, and removal of the solvent or supercritical liquid. Process according to claim 1, characterized in that it further comprises: f) mixing the pressed oil with a solution containing the residual oil from step e) and then neutralizing the mixture to remove residual free fatty acids therefrom; 20 g) cooling the neutralized mixture, precipitating on standing and filtering the mixture, h) decolorizing the filtrate with an adsorbent and then removing the solvent and, i) removing the odorants in the oil. Method according to claim 2, characterized in that step a) is omitted. Process according to any one of claims 1 to 3, characterized in that the cores are obtained by drying the squeeze cake from blackcurrant juices, grinding 30 and sieving it to obtain particles of 1 to 1.5 mm and separating the cores by air classification. 5. A process according to claim 1 or 2, characterized in that the cores are washed with ethanol under reflux. Method according to any one of claims DK 169557 B1 1 to 3, characterized in that the flakes are pressed with a pressure of from 490 to 785 bar (500-800 kg / m 2) while maintaining the temperature of the press head below 90 ° C. Process according to any of claims 5 to 3, characterized in that the press cake is extracted with reflux hexane. Process according to claim 2 or 3, characterized in that in step f) the non-polar solvent is partially evaporated to obtain a solution containing. 80-90% by weight of the solvent, neutralize the solution with concentrated alkali and in step g) keep the temperature of the solution from 0 ° C to 4 ° C for approx. 24 hours and filter this. Process according to claim 2 or 3, characterized in that the filtrate is decolorized in step h) with from 2 to 8% of an activated adsorbent, based on the weight of the fats in solution. Process according to claim 2 or 3, characterized in that the air substances are removed from the oil 20 step i) at a temperature of from 140 ° C to 220 ° C and in a vacuum below 133 Pa (1 torr).