PROCESS FOR ENRICHMENT OF FAT WITH REGARD TO POLYUNSATURATED FATTY ACIDS AND PHOSPHOLIPIDS, AND APPLICATION OF SUCH ENRICHED FAT

Abstract: A process for enrichment of fat with regard to polyunsaturated fatty acids and phospholipids implicates extraction of the fat with a fat-solving alcohol, whereafter the fat is precipitated in fractions. The precipitation is accomplished through evaporation, separation and further stepwise precipitation and evaporation. Each step of precipitation can be regulated through adding solvent. The produced fat is applied as feed supplement for human and animal life, as feed supplement destined for food or fodder, as ingredient in feed products, or alone or as ingredient in products within health or medical care.

Description: PROCESS FOR ENRICHMENT OF FAT WITH REGARD TO POLYUNSATURATED FATTY ACIDS AND PHOSPHOLIPIDS, AND APPLICATION OF SUCH ENRICHED FAT. The present invention relates to a process for enrichment of fat with regard to polyunsaturated fatty acids and phospholipids (PL). It is known that the composition of fatty acids in fat in the diet is important for the prophylaxis of heart diseases and arterioschlerosis, and that it is desirable to use fat with a high content of polyunsaturated fatty acids. It is also known that such acids as part of phospholipids are easier absorbed and ingested in the body. Very important in this connection are the unsaturated fatty acids: EPA (eicosapentaenoic acid), denotation C20:5n-3, DHA (dokosahexaenoic acid), denotation C22:6n-3, DPA (dokosapentaenoic acid), denotation C22:5n-3. Most of the marine fish- and mammal species have fat that contains relatively large quantities of EPA and DHA bound in phospholipids. With industrial production of lipids from animal- and vegetable materials, experience has learned that is is more difficult to separate phospholipids than triglycerids from body tissues by conventional methods (cooking, pressing, extraction etc.), and that the fat remaining in the tissues will be enriched with phospholipids by such production methods. Through extraction with a polar extraction liquid most of the remaining fat can, however, be recovered. In order to increase the positive effect upon health from this type of fat, it is desirable to enrich the fat with regard to both EPA, DHA, DPA and phospholipids; however, without altering the natural biological structure and properties of the fat. Such enriched fat will be of great importance not only for the prophylactic effect concerning heart diseases and arterio¬ sclerosis, but also for better nutrition for human and animal lives, especially in the prenatal and the early growth periods. An adequate supplement of such enriched fat in the diet would assist in securing right nutriment combinations and thereby noticeably reduce mortality and improve growth conditions for such lives. This is of special interest for fish farming, where supple¬ mentary quantities of enriched fat in normal feed combinations, at approximate amounts, 0.5 to 1% of the feed, or, referred to the total fat, 10 to 20% of the fat in the feed, could, according to published test reports, probably reduce mortality considerably and increase growth rate with about 10%. Such enriched fat is according to the invention obtained by the following steps, a) that the fat is extracted with a fat dissolving, polar alcohol, and b) that the dissolved fat is then precipitated in fractions with increasing content of polyunsaturated fatty acids and phospholipids, through b-, that the liquid solution is concentrated through evapo¬ ration until precipitation of the first fat fraction starts, b 2 that the first fat fraction is separated, b 3 that further precipitation and concentration are made in steps, through separation of another fat fraction with the start of each following precipitation, and b. that the number of precipitated fractions and relative quantities with each precipitation can be regulated through adding liquid. By this process, according to the invention, an adjustable enrichment of EPA, DHA and DPA together with phospholipids is attained without chemical transformation through, for example, esterification of the fatty acids. Isopropanol is especially suitable as an extraction solvent. It dissolves fat effectively, forms an azeotropic mixture adequate for the process and has good preservation effect. Ethanol can also be used for this process. It is essential by this procedure that the last separated fat fractions have, or can be given, a higher enrichment of natural phospholipids and polyunsaturated fatty acids of the type n-3. According to the invention it has been demonstrated that polyunsaturated fatty acids are being enriched in the later fractions, mainly as phospholipids, i.e. that the saturated fats, mainly as triglycerides, are the first to precipitate during the evaporation. Thereby it becomes possible to produce fat with a high content of phospholipids and polyunsaturated fatty acids, in particular the above-mentioned n-3 fatty acids. Marine fats are especially rich on the above-mentioned n-3 fatty acids, and it is thus natural to choose fish for raw material, also from reasons that a raw material can be utilised that cannot be used directly for food and therefore is cheap (industry fish, fish offal etc.). An example of the invention will be described in the following. Example. Iced fjord herrings of consumption quality (i.e. below 15 mg N per 100 g of herring) were worked into presscake in the usual way at boiling temperature of 60°C. After pressing the presscake was passed through a fast chopper, mixed with isopropanol, and stabilised with antioxidant. The presscake had a water content of about 50%. To 880 g of presscake in a 5 liter flask was added 3080 g of isopropanol, to the effect that the isopropanol content made up about 87.5% of the total for isopropanol plus water, i.e. azeotropic concen¬ tration. The flask content was transferred to a glass with a plastic film as lid and heated to 55°C in about 1 hour under steady stirring and flushing with nitrogen. Thereafter the suspension was filtered, whereby about 2865 -g of filtrate was obtained. The filtrate was concentrated through evaporation in a vacuum film evaporator until precipitation started, which was registered visually through observing hazing of the solution. 2415 g isopropanol had then evaporated. The rest, 450 g, was centrifugalised, whereby about 6 g of a yellowish substance was obtained (fraction 1). A second evaporation started with 430 g solution and was interrupted with a rest of 212 g, as hazing started. The rest was centrifugalised, and the obtained substance was about 2 g (fraction 2) . A third evaporation started with about 192 g and was inter¬ rupted with a rest of 115 g as a faint hazing was registered. This rest was centrifugalised. The separated substance was yellowish and weighed 2 g (fraction 3). A fourth evaporation started with 105 g and was interrupted with a rest of 77 g, as a faint hazing was registered. Centri- fugalising did not result in any separate substance, and evaporation was continued until the smell of isopropanol ceased. The residue was brownish and resembled molasses both in colour and consistence. Weight 22 g (fraction 4). Each fraction (1 - 4) was analysed. The combination of fatty acids, the sum of saturated, the sum of polyunsaturated, the sum of n-3 fatty acids and the sum of the acids EPA and DHA are shown in table 1 below. From table 1 it is seen that the sum of EPA + DHA has been raised from 32.36% to 42.19%, i.e. with 30%. The test was repeated with the same raw material, and this gave about the same result. The analysis did also include finding the content of phospholipids (PL) in the fractions, and as can be seen from table 2, there is a marked increase from 49% in the first to 78% in the last fraction. Another test was made with same type of raw material, but at a different time of the year. The results are given in table 2 under raw material B. The values for the n-3 fatty acids from this test were somewhat lower, but the increase is relatively much higher: 54.5%, i.e. considerably higher than for raw material A. Raw material B did also show a marked increase in phospholipids from 10% in the first to 86% in the last fraction. Table 1. The fatty acid combination (% ) in different fractions after extraction. Fatty acids 1 2 3 4 12:0 0.21 0.24 0.14 0.04 14:0 7.99 4.35 4.22 3.78 16:0 10.54 8.08 7.67 10.77 18:0 2.01 1.85 1.81 1.53 20:0 0.14 0.30 0.16 0.13 24:0 trace 1.05 0.21 0.18 16:1 4.65 3.04 3.39 3.07 18:1 10.79 11.55 11.76 12.76 20:1 6.94 7.59 7.10 5.87 22:1 8.68 11.98 9.17 6.82 24:1 - 0.43 0.56 0.51 0.29 16:2n-4 0.81 0.57 0.73 0.65 16:4n-l 0.77 0.30 0.48 0.13 18:2n-6 1.49 1.14 1.10 1.06 18:3n-6 0.09 0.09 0.07 0.06 18:3n-3 1.54 1.03 1.04 0.89 18:4n-3 3.26 1.47 1.64 1.04 20:2n-6 0.11 0.11 0.12 0.10 20:3n-6 20:4n-6 1.24 0.95 0.95 0.89 20:4n-3 0.55 1.53 - - 20:5n-3 11.18 8.49 11.45 12.12 21:5n-2 trace 0.19 0.20 0.29 22:5n-3 0.84 0.89 0.88 0.91 22 : 6n-3 21.18 23.95 27.69 30.07 Sum saturated 20.89 15.87 14.21 16.43 Sum the monoenes 31.49 34.72 31.93 28.81 Sum PUFA 43.06 40.71 46.35 48.78 Sum n-3-fatty,acids 37.36 37.36 42.70 45.60 Sum.EPA + DHA 32.36 32.44 39.14 42.19 P/S 4 2.06 2.57 3.26 2.97 1) n-x, where x states location of first double bond reckoned from the methylene end of the fatty acid 2) PUFA = polyunsaturated fatty acids 3) 20:5n-3 (EPA), 22:6n-3 (DHA) 4) The ratio between sum polyunsaturated (P=PUFA) and saturated (S) fatty acids. Table 2 Raw material A Raw material B Fraction II III II III Fatty acids Sum saturated and the monoenes: 53.7 47.8 44.1 64.9 54.7 53.6 Sum the polyenes: 46.9 52.2 55.7 35.1 45.3 46.4 Sum n-3: 37.5 40.8 46.8 25.6 34.5 35.7 Sum EPA-DHA: 32.2 37.0 43.4 20.2 29.2 31.2 Phospholipids: % 49 76 78 10 67 86 Triglycerides: % 51 19 16 89 30 7

Claims: CLAIMS. 1. Process for enrichment of fat with regard to polyunsaturated fatty acids and phospholipids, characterized in a) that the fat is extracted with a fat dissolving, polar alcohol, and b) that the dissolved fat is then precipitated in fractions with increasing content of polyunsaturated fatty acids and phospholipids, through b, ) that the liquid solution is concentrated through evapo¬ ration until precipitation of the first fat fraction starts, b„ ) that the first fat fraction is separated, b-,) that further precipitation and concentration are made in steps, through separation of another fat fraction with the start of each following precipitation, and, b. ) that the number of precipitated fractions and relative quantities with each precipitation can be regulated through adding liquid. 2. Process in accordance with claim 1, characterized in that isopropanol is used as extraction solvent. 3. Application of fat produced and enriched with regard to polyunsaturated fatty acids and phospholipids by the process according to claim 1 or 2 a) as feed supplement for human and animal lives, especi¬ ally in the first development-/growth periods, b) as feed supplement for living animals which are destined to serve as food or fodder and which are desired to be enriched with polyunsaturated fatty acids and phospholids, c) as ingredient in feed products which are desired to be enriched with polyunsaturated fatty acids and phospholipids, or d) as separate substance or as component in other products, which are to be used for the purpose of prevention and/or treat¬ ment of diseases within health or medical care.

Inventors: ASKELAND ATLE, GRIMSTAD PER, ROETTINGEN JAN, SOLA EINAR, ASKELAND, ATLE, GRIMSTAD, PER, ROETTINGEN, JAN, SOLA, EINAR
Applicants: ASKELAND ATLE, GRIMSTAD PER, ROETTINGEN JAN, SOLA EINAR, ASKELAND, ATLE, GRIMSTAD, PER, ROETTINGEN, JAN, SOLA, EINAR
Application year: 1990
Main classification: C11B3
IPC codes: A23D9, A23K1, C11B1, C11B3, C11B7