Flaxseed linoleic acid

Goodridge, J., Ingalls, J., and Crow, G. 2001. Transfer of omega-3 linolenic acid and linoleic acid to milk fat from flaxseed or linola protected with formaldehyde. Can. J. Anim. Sci. 81, 525-532. Greenberg, S.M., Calbert, C.E., Savage, E.E., and Deuel, H.J., Jr. 1950. The effect of fat level of the diet on general nutrition. J. Nutr. 41, 473- 186. 

Fatty acid composition of regular flax oil is different from other commercial oils because of the very high contribution of ALA, usually above 50% (Table 2). Because of the high content of this unique fatty acid, flaxseed and flax oil are often used as food supplements, where enrichment with omega-3 fatty acids is needed. This fatty acid is susceptible to oxidation it oxidizes 20 0 times faster than oleic acid and 2 times faster than linoleic acid (8). This property makes the oil a good material for paint and plastic production where fast oxidation is required. Flax oil contains low amounts of saturated fatty acids (SFA) compared with low linolenic flax oil (Linola), soybean, and sunflower oils however, it is higher than canola oil (Table 2). Canola oil contains the lowest amount of SFA among all commercial oils. 

The contribution of linolenic acid in flaxseed oil showed a wide range and was affected by the growing conditions. Flax varieties grown in Western Canada, average from 495 samples analyzed, contained 5% palmitic acid (16 0), 3% stearic acid (18 0), 17% oleic acid (18 1), 15% linoleic acid (18 2), and 59% linolenic acid (18 3) (11). Although similar varieties were grown in North Dakota, the 11 cultivars assessed showed the following fatty acid composition 5-6% of 16 0, 3-6% of 18 0, 19-29% of 18 1, 14-18% of 18 2, and 45-52% of 18 3 (12). 

Analysis performed on varieties of flaxseeds collected from different flax growing regions of the world and later grown in Morden, Manitoba, Canada, showed even wider distributions of oleic acid 14-60%, linoleic acid 3-21%, and ALA 31-72% (13). All of these data indicate that within flax, there is a wide distribution of fatty acids, and this variability can be used for developing specialty oils based on traditional breeding and to avoid GMO oils. 

Nordstrom DC, Honkanen VE, Nasu Y, Antila E, Frimen C, Konttinen YT. Alpha-linoleic acid in the treatment of rheumatoid arthritis. A double-blind, placebo-controlled and randomized study flaxseed vs. safflower seed. Rheumatol Int 1995 14 231-234. 

Linseed-oil—Flaxseed-oil—Oleum Uni (U. S., Br.)—is a dark, yellowish-brovvn oil of disagreeable odor and taste. In it oleic acid is, at least partially, replaced by linoleic acid, whose presence causes the oil, on exposure to air, to absorb oxygen and become thick and finally solid. This drying power is increased by-boiling the oil with litharge (boiled oil). 

The production requires 2 fermentations. In the first fermentation, lipase enzymes liberate the unsaturated fatty acids of flaxseed oil. During the first feraientation, the hydrolyzed fatty acids, linolenic acid, linoleic acid and oleic acid, are converted to (respectively) 10-hydroxy-12(Z),15(Z)-octadecadienoic acid, 10-hydroxy-12(Z)-octadecenoic acid and 10-hydroxydecanoic acid by Pseudomonas sp. NRRL-2994. Pseudomonas sp. produced stereochemically pure d (R)-isomers of each of the hydroxy fatty acids (>95.8%) 23) at a concentration of >12 g/L in the fermentation broth. The resulting hydroxy fatty acids were recovered by phase separation technique, and used for the second fermentation. 

Fig.1. The proportion of radioactivity in fatty acids from liver and brain phospholipids after an oral dose of 1- X-linoleic acid in weanling rats. The pups were from diet groups whose mothers had been raised on diets containing either safflower oil or flaxseed oil as the sole dietary lipid. The dams had consumed the diet from 1 wk before mating until weaning of the pups. Pups were killed (16 d old) 24 h after oral dosing and tissues were isolated. Results are means, n = 2 rats/diet group. Further details of the methods are found in Reference 12. Abbreviations ALA, a-linolenic acid EPA, eicosapentaenoic acid DPA, docosapentaenoic acid DHA, docosa-hexaenoic acid SM, saturated plus monounsaturated fatty acids.

The right balance of n-6 and n-3 polyunsaturated fatty acids (PUFA) is important for good health. The n-3 PUFA such as eicosapentaenoic acid PA) and docosahexaenoic acid (DHA) are mainly found in fish oils. Marine plants can convert a-linolenic acid (ALA) into EPA and DHA, which find their way through the food chain to fish tissues. Another source of n-3 PUFA is the ALA that is found mainly in flaxseed, canola, and soybean oils. Unlike plants, mammals cannot convert oleic acid into linoleic acid, linoleic acid into ALA, or convert n-6 PUFA to n-3 PUFA. Linoleic acid and n-3 PUFA are therefore known as essential fatty acids (1). 

Bell, J. A., Griinari, J. M., Kennelly, J. J. (2006). Effect of safflower oil, flaxseed oil, monen-sin, and vitamin E on concentration of conjugated linoleic acid in bovine milk fat. Journal of Dairy Science, 89, 733-748. 

The characteristic fatty acid patterns of plant triacylglycerols are to some extent under genetic control (see Section VI). In addition, environmental factors may modify the basic patterns, the extent of modification depending on the species. Thus the seed oils of plants grown in cool climates tend to be more unsaturated than those grown in warm climates (Hitchcock and Nichols, 1971). The chief influence seems to be on the characteristic fatty acid of the seed, so that for example in flaxseed oil there is a marked decline in the proportion of linolenic acid between 10° and 30°C and a corresponding increase in the proportion of its precursor, oleic acid (Canvin, 1965). Similarly, the proportion of linoleic acid in sunflower seed oil steadily declines between 10° and 30°C, to be replaced by oleic acid. Yet the linoleic content of safflower and the ricinoleic acid of castor are unaffected by the same variation in temperature (Canvin, 1965). All rules have exceptions, and the experiments of Appelqvist (1975) showed that different lines of zero-erucic acid rape could respond differently to the same climatic variations. 

Linoleic acid is found in soybean, safflower and com oil, nuts, seeds, and some vegetables. a-Linolenic acid is found in flaxseeds, walnuts, and their oils canola oil is also a good source of a-linolenic acid. Edible oils rich in monounsaturated fatty acids are stable, flavorful, and nutritious for humans and animals. Oleic acid-rich soybean oil is more resistant to degradation by heat and oxidation and requires little... 

Alpha-linoleic acid (molecule structure is shown in Fig. 5.100) belongs to a group of omega-3 polyunsamrated fatty acids. It occurs as an ester of glycerol in small amounts in vegetable fats, especially flaxseed oil, and animal fats. 

Flaxseed has a high ALA content, generally constituting 50-62% of total fatty acids (Daun et al., 2003). Dorrell (1970) reported that fatty acid distribution in flaxseed varied depending on the anatomical fractions. The hull is the main source of palmitic acid, but it has a relatively low oil content. Lower oleic and ALA and higher linoleic contents are present in the embryo compared to whole seed. Oomah and Mazza (1997) also observed higher levels of palmitic acid in the hull. However, the hull and whole seed gave similar ALA values, compared to dehulled seed. 

Some physicochemical properties of conventional flaxseed oil and low linolenic varieties are presented in Table 1. The higher specific gravity of 0.935 observed for flaxseed oil than other vegetable oils can be directly attributed to the high contribution of linolenic acid. It is in line with the specific density of fatty acids that increases from 0.895 to 0.9038 and to 0.914 for oleic, linoleic, and linolenic acids, respectively (7). 

The seed of perilla contains 31-51% of oil, which is similar in composition to flaxseed oil, with a higher contribution of PUFA of over 70% (Table 4). The oil is highly unsaturated, with an iodine value of 192-208-g iodine /100-g oil (Table 4). Perilla oil contains over 60% linolenic acid with equal amounts of both linoleic and oleic acids (Table 4). Specific gravity of this oil is higher than flax oil because of a higher contribution of PUFA. Other physical parameters of this oil reflect the composition of its fatty acids. 

Caston and Leeson (1990) reported that the feeding of flaxseed increases n-3 FA and slightly increases n-6 FA as well. The more flaxseed oil in the feed, the higher the amounts of linoleic and linolenic acids, as well as ERA and DHA, present in the egg yolk lipids. 

This chapter focuses on the preparation of thermosets, polyesters, and other polymers from industrial oilseeds. Nature has provided a few examples of plant oils that possess multiple functional groups needed for polymer synthesis, such as castor (Ricinus communis), lesquerella (Lesquerella fendleri), and vemonia (Vernonia galamensis) oils, enriched in —OH and epoxide-functionalized fatty acids ricinoleic, lesquerolic, and vemolic acid, respectively (Table 3.1). Many common plant seed oils (eg, soybean, cottonseed, com, soybean, safQower, sunflower, canola, jatropha, and olive oils) are enriched in Ci6—Cig saturated and mono- and diunsaturated fatty acids, such as palmitic (16 0), oleic (18 l-9c), and linoleic (18 2-9c,12c) acids and lesser amounts of a-linolenic acid (18 3-9c,12c,15c) however, linseed (flaxseed), camelina (Camelina saliva). 

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