Oleic acid content

Reversed-phase HPLC has been used to analyze the oxidation products of triacylglycerols in edible oils. The detection is often based on monitoring the conjugated dienes with an ultraviolet detector (234-235 nm). However, the UV detector provides no information about oxidation products without a conjugated diene structure, e.g., products of oleic acid. Information about these compounds is important when oils with a high oleic acid content are studied. The most common universal detector types—refractive index and flame ionization detectors—are not sensitive enough to detect small amounts of oxidation products. 

Oleic acid content = 77.9 wt% before conversion to biodiesel. c4 1 v/v soybean oil methyl ester/tallow methyl ester. 

Oleic acid content = 77.9 wt% before conversion to biodiesel. 

Oocoa butter (stearic fraction) contains about 33% oleic acid occupying the second position only. Consequently, positional specific lipases do not react with oleic acid. The Non-specificity Index (NSI) is based on the decline in oleic acid content in the triglycerides in relation to the lauric acid incorporation. A positional specific lipase will give a non-specificity index of 0 whereas a non-specific lipase will give a non-specificity index of 1. 

Monounsaturated fatty acids. The report that monounsaturated fatty acids (viz., oleic acid) were just as effective as polyunsaturated fatty acids (viz., linoleic acid) in lowering plasma total and low-density lipoprotein (LDL) cholesterol (100) aroused interest in the nutritional properties of canola oil. Canola oil contains 60% oleic acid and is second only to olive oil, among the common vegetable oils, in oleic acid content. Although avocado oil and high-oleic sunflower oil also contain high levels of oleic acid (>70%), they are minor constituents in the average diet. 

High oleic acid canola oil is another development pursued in Canada, the United States, Sweden, Australia, and elsewhere (137). As with low linolenic acid canola oil, the aim was to produce stable frying oil, which will not need hydrogenation and thus avoid fraui-isomers formation. The oleic acid content in oil from seed developed in Canada is at about 78%, whereas linoleic and linoleic acids are lowered to approximately 8% and 3% respectively (see Table 2). Saturated fatty acid content is unchanged from the standard canola oil. There is limited commercial seed production for export to Japan. Also, there is increasing acceptance of the oil in Canada and the United States. The frying performance in tests was found to be similar to... 

TABLE 9. AOM Time (hr) for Refined Sunflower Oils of Different Oleic Acid Content [based on (36)]. 

Sunflower oil extracted from different types of hybrid may have different compositions. It is expected that the degree of unsaturation will influence the oxidative stability of sunflower oil markedly. AOM time measurements were used to determine the influence of oleic/linoleic ratio on the oxidative stability of sunflower oil (36). Oil samples extracted (refined and deodorized) from three progenies of cultivar Per-venets were analyzed, as well as other oil samples from different regions of the United States. The oleic acid content thus ranged from 18% to 89%, and the linoleic acid content decreased from 69% to 1 % the saturated fatty acid content was nearly constant. AOM values increased from 11 hours for the oil containing the least amount of oleic acid to 100 hours for that with the oleic acid highest content. These results show the importance of monounsaturated fatty acid content on the oxidative stabihty of sunflower oil. 

The fluted pumpkin Telfaria occidentalis) is a tropical gourd native to West Africa. It is taxonomicafly classified as a member of the Curcubitaceae family. The fruits are very large and weigh up to 13 kg, but only the seeds are edible (33). The seeds are very rich in both protein and fat, containing approximately 28% and 55%, respectively, from whole oven-dried fluted pumpkin seeds (26). The fatty acid profile of fluted pumpkin seeds demonstrated a high oleic acid content of 35.4% and a total saturated fatty acid concentration over 34% (Table 7) (26). Significant level of linoleic acid (18 2n-6) was also detected in the seed oil. 

High oleic acid content sunflower oil with good oxidative stability and emollient properties is commercially available for use in cosmetic formulations. Sunflower oil with marked oxidative stability is particularly suitable for the manufacture of sunscreen agents. " ... 

Increasing the oleic acid content of milk fat from 26% to over 40% by feeding calcium salts of HOSO containing more than 86% oleic acid at the rate of 7.5% of diet dry matter weight to Holstein cows did not affect the sensory and physicochemical properties of Latin American white cheese (Queso Blanco). There was also no difference (as a result of the modified and improved fatty acid profile) between the firmness of the product from modified milk and that made from normal milk (Aigster et al., 2000). 

---