Fatty acid in vegetable oils

Polyunsaturated fatty acids in vegetable oils, particularly finolenic esters in soybean oil, are especially sensitive to oxidation. Even a slight degree of oxidation, commonly referred to as flavor reversion, results in undesirable flavors, eg, beany, grassy, painty, or fishy. Oxidation is controlled by the exclusion of metal contaminants, eg, iron and copper addition of metal inactivators such as citric acid minimum exposure to air, protection from light, and selective hydrogenation to decrease the finolenate content to ca 3% (74). Careful quality control is essential for the production of acceptable edible soybean oil products (75). 

Table 1. Common fatty acids in vegetable oil and animal fat triglycerides [2,3]...

The most abundant fatty acids in vegetable oils and fats are palmitic acid (hexa-decanoic acid or 16 0), oleic acid ([9Z]-octadec-9-enoic acid or 18 1 cis-9), and lino-leic acid (cis, cis-9,12-octadccadicnoic acid or 18 2 cis-9 cis-12) [21], Other fatty acids are found in special oils (e.g. 80% 87% ricinoleic acid in castor oil) [23], but these oils are quite rare. Castor oil, for example, has a production rate of 610,000 tons/year compared to the top four palm oil (46 million tons/year), soya oil (40 million tons/year), rapeseed oil (24 million tons/year), and sunflower oil (12 million tons/ year) [24]. Further sources of fatty acids are tall oils (2 million tons/year) [25] and to a lesser degree synthetic fatty acids derived by mainly hydroformylation and hy-drocarboxylation of olefins [23], The summed fatty acid production is estimated to be 8 million tons/year (2006) [23],... 

The reaction rate is assumed to be first-order with respect to A and zeroih-order with respect to B, This type of membrane reactors is suitable for such reactions as hydrogenation of unsaturated fatty acids in vegetable oils on Pd and Ni catalysts. 

The pro-oxidant effect of free fatty acids in vegetable oils is widely known. To determine their influence (86), pure oleic acid was added (up to 3%) to a high-oleic sunflower oil extracted by cold-pressing. The effect intensity was found to be directly related with the concentration of free fatty acids. 

Large supply of naturally derived lipids can be obtained from plants in which many oils and fatty acids can be readily extracted and purified. Animal sources (e.g., eggs or milkfats) are used to derive complex lipids such as phospholipids and cholesterol. Yield from natural sources is dependent on the weight-percent composition and the efficiency of the extraction procedure. The constitution of fatty acids in vegetable oils varies widely from different sources. For example, oleic acid is present at 64.6% by weight in olive oil but is present at only 0.7% in palm kernel oil. Similarly, castor oil triglyceride is comprised of almost entirely ricinoleic chains. There are numerous raw material suppliers of oils and oil fractions worldwide. As such, the relative cost of bulk purified... 

Fabbri, D., Baravelli, V., Chiavari, G., and F rati, S. Profiling fatty acids in vegetable oils by reactive pyrolysis-gas chromatography with dimethyl carbonate and titanium silicate. Journal of Chromatography A, 1083, 52-57. 2005. 

The content of saturated fatty acids in vegetable oils ranges from a low of 5% in rapeseed and mustard oils to about 15% in corn and soybean oils. Peanut oil contains about 20% saturated fatty acids, appreciable amounts of which are longer than Cig. In contrast to vegetable oils, animal fats and fish oils are much richer in saturated fatty acids, i.e., chicken fat 33%, lard 40%, beef and mutton tallow 48%, and fish oils 17-33% (Sheppard eta/., 1978). 

Are the fatty acids in vegetable oils more saturated or unsaturated than those in animal fats Explain your answer. (Table 20.2)... 

Chromosomes are composed of proteins and nucleic acids. 6. Fatty acids in vegetable oils are more unsaturated than fatty acids in animal fats. 

Carol, I. and Grigore, B. (1963-1964) Determination of fatty acids in vegetable oils. Lucrarile Institului de Cercetari Alimentare 1, 451-468. 

The fatty acids in vegetable oils are omega-6, in which the first double bond occurs at the sixth carbon, counting from the CH3 — end. However, the fatty acids in fish oils are mostly the omega-3 type, in which the first double bond occurs at the third carbon from the CH3— end. 

Several reviews have already appeared on this subject since Hil-ditch s monumental work (Hilditch and Williams, 1964). We wish only to point out how the new research methods developed in the last ten years have permitted a much more detailed knowledge of the distribution of the fatty acids in vegetable oil triglycerides. 

Holcapek, M., Jandera, R, Fischer, J., 2001. Analysis of acylglycerols and methyl esters of fatty acids in vegetable oils and in biodiesel. CriL Rev. AnalyL Chem. 31 (1), 53-56. 

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