Ot-linolenic acid

The current interest in dietary fat, however, stems primarily from its implication in the origin of several chronic diseases. Interest has centered on both the amount and type of dietary fat in the development of cardiovascular disease, cancer, hypertension, and obesity. As a result, dietary recommendations in many countries call for a reduction in total fat intake, to 30% of energy, and in saturated fat intake, to less than 10% of energy. In addition, some nutrition recommendations specify recommended levels of n-6 and n-3 fatty acids in the diets. Hence, the source of fat in the diet has assumed considerable importance over the past few years. Interest in the nutritional properties of canola oil developed because of its fatty acid composition (Table 2). Canola oil is characterized by a low level of saturated fatty acids, a relatively high level of monounsaturated fatty acids, and an appreciable amount of the n-3 fatty acid ot-linolenic acid (18 3 n-3). 

Linoleic acid and ot-linolenic acid are essential fatty acids and are the important fatty acids involved in the metabolic pathway of prostaglandin synthesis. 

Walnuts contain about 65% lipids, however, considerable differences exist among varieties (range 52-70%, w/w) (1,40). Walnuts also contain 15.8% protein, 13.7% carbohydrate, 4.1% water, and 1.8% ash (w/w) (1). The fatty acid composition of walnut oil is unique compared with other tree nut oils for two reasons walnut oil contains predominantly linoleic acid (49-63%) and a considerable amount of ot-linolenic acid (8-15.5%). Other fatty acids present include oleic acid (13.8-26.1%), palmitic acid (6.7-8.7%), and stearic acid (1.4—2.5%) (Table 5) (40). The tocopherol content of walnut oil varies among different cultivars and extraction procedures and ranges between 268 mg/kg and 436 mg/kg. The predominant tocol isomer is y-tocopherol (>90%), followed by a-tocopherol (6%), and then (3- and 8-tocopherols (41). Nonpolar lipids have been shown to constitute 96.9% of total lipids in walnut oil, whereas polar lipids account for 3.1%. The polar lipid fraction consisted of 73.4% sphingolipids (ceramides and galactosylcera-mides) and 26.6% phospholipids (predominantly phosphatidylethanolamine) (42). Walnut oil contains approximately 1.8g/kg phytosterols (1), primarily p-sitosterol (85%), followed by A-5-avenasterol (7.3%), campesterol (4.6%), and, finally, cholesterol (1.1%) (42). 

The fatty acid profile of two cold-pressed black raspberry seed oils demonstrated high concentrations of both n-3 and total unsaturated fatty acids. The concentration of ot-linolenic acid (18 3n-3) was 35% of total fats, and unsaturated fatty acids comprised 98-99% (Table 1). Linoleic acid was the predominant fatty acid (Table 1) however, the ratios of n-6 to n-3 fatty acids were very low at 1.6 1. The other measurable fatty acids included oleic (18 ln-9) and palmitic (16 0) acids (Table 1). The overall fatty acid composition of black raspberry seed oil was very similar to red raspberry seed oil (1) (Table 1). 

The cherry tree Prunus avium L.) is a member of the Rosaceae family. Cherry seed contains about 18% oil on a dry weight basis (48). Significant levels of oleic acid were detected in the cherry seed oils prepared by hexane extraction using a Soxhlet apparatus. Oleic acid comprised 24—38% of the total fatty acids from three different varieties of cherry fruits (Table 7) (48). Linoleic acid was the major fatty acid in the cherry seed oil, and ranged 40 9% in the seed oil, along with ot-eleostearic (18 n-5), palmitic, stearic, arachidonic, and ot-linolenic acids (Table 7). alpha-eleostearic acid comprising 10-13% of cherry seed oil, is a conjugated... 

Brenna, J. T., Salem, N., Jr., Sinclair, A. J., and Cunnane, S. C. (2009). ot-Linolenic acid supplementation and conversion to n-3 long-chain polyunsaturated fatty acids in humans. Prostaglandins Leukot. Essent. Fatty Acids 80,85-91. 

Essential fatty acids or polyunsaturated fatty acids include linoleic acid, Ot-linolenic acid (and probably arachidonic acid in children). They must be taken in the diet, and are found in fish and vegetable oils. They contain C03 or C06 bonds (see page 29). 

The list of natural fatty acids exceeds 1000, but commercial interest is limited to a smaller number— perhaps around 20. Ignoring the lipid membrane, rich in ot-lino-lenic acid and present in all green tissue, the three dominant acids in the plant kingdom are palmitic, oleic, and linoleic, sometimes accompanied by stearic acid and by linolenic acid. Others, occuring in specialty oils, include myristic, lauric, erucic, hexadecenoic, petroselinic, y-linolenic acid, eleostearic and isomers, ricinoleic, and vemolic (Table 1). 

Oil made horn the new variehes ot rape is almost free ol Hie long chain (ally acid, erucic add, while the oloic acid conlent is significanlly higher. Eicept for the presence of linolenic acid, the composilion ol the new oil greatly resembles olive oil Canada renamed Hie changed plant H is called canola. 

Pecan tree (Carya illinoinensis) is native to the United States but has also been naturalized for commercial pecan production throughout the world, including Australia, South Africa, and several middle eastern and South America countries (33). Fat is the predominant constituent in all pecan varieties, ranging from 65% to 75% (w/w) (1, 33, 34). Other constituents include 13.9% carbohydrate, 9.1% protein, 3.5% water, and 1.5% ash (w/w) (1). The predominant fatty acids present in pecan oil are oleic (55%), linoleic (33%), linolenic (2%), palmitic (7%), and stearic (2%) acids (Table 4) (34). The most predominant tocol in pecan oil was y-tocopherol (176mg/kg), followed by ot-tocopherol (lOmg/kg), and then 5- and p-tocopherols (6.2mg/kg) (1). Pecan oil also contains 0.73 g/kg phytosterols that exist primarily as (3-sitosterol (around 90%) (1). 

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