Sources of fatty acids

In addition to dietary sources, the body is also capable of synthesizing fatty acids. The exceptions to this are the so-called essential fatty acids, linoleic and linolenic acids, which must be supplied in the diet (see section 2.4). The main site of fatty acid synthesis in the body is the liver. 

---

The composition of common fats and oils are found in Table 1. The most predominant feedstocks for the manufacture of fatty acids are tallow and grease, coconut oil, palm oil, palm kernel oil, soybean oil, rapeseed oil, and cottonseed oil. Another large source of fatty acids comes from the distillation of cmde tall oil obtained as a by-product from the Kraft pulping process (see Tall oil Carboxylic acids, fatty acids from tall oil). 

Nicotinic acid decreases formation and secretion of VLDL by the liver (mechanism III in Fig. 23.2). This action appears secondary to its ability to inhibit fatty acid mobilization from adipose tissue. Circulating free fatty acids provide the main source of fatty acids for hepatic... 

We begin this chapter with a brief discussion of the sources of fatty acids and the routes by which they travel to the site of their oxidation, with special emphasis on the process in vertebrates. We then describe the chemical steps of fatty acid oxidation in mitochondria The complete oxidation of fatty acids to C02 and H20 takes place in three stages the oxidation of long-chain fatty acids to two-carbon fragments, in the form of acetyl-CoA (/3 oxidation) the oxidation of acetyl-CoA to C02 in the citric acid cycle (Chapter 16) and the transfer of... 

The x-ray side-spacing results allow us tentatively to classify the acid-soaps into three phases, determined chiefly by chain length but to some extent by source of fatty acid. Since the fatty acids were all of high... 

Adipose tissue can metabolize glucose by means of the HMP, thereby producing NADPH, which is essential for fat synthesis (see p. 184 and Figure 24.5, ). However in humans, de novo synthesis is not a major source of fatty acids in adipose tissue. 

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],... 

Acting as a source of fatty acids, which when liberated from triacyl-glycerols by the action of lipases, contribute directly to cheese flavor... 

Fatty Acids. Of the total fatty acids produced annually in the United States, amounting to more than 450,000 tons, 35 percent come from tall oil. The solvent extraction of pine wood yields only 1 percent fatty acids and their esters. The yield is not increased, however, by paraquat (dipyridyl herbicides) treatment. Hence, the kraft-pulping industry will continue to be the major source of fatty acids from wood. The approximate distribution of uses of the fatty acids are ... 

The trivial names that indicate the initial source of fatty acids are used more often than the lUPAC names in the industry. For example, butyric acid is a major component of butter flavor, palmitic acid comes from palm kernel, and oleic acid from olives. 

Although significant strides have been directed at reducing fat content in food products, certain lipid ingredients and sources of fatty acids are used to enhance the health and nutritional quality of foods. For example, CLA isomers were enriched in both dairy and nondairy products to convey its anticancer and antiobesity effects that were reported repeatedly in animal studies (39). Sources of n-3 PUFAs are also added directly to infant formula to provide sufficient DHA for normal development of the nervous system during early infancy. In the United States, DHA was approved by the FDA in 2001 to be added into infant formula (40, 41). 

Tamarind seed is a by-product of the tamarind pulp industry. Presence of tannins and other dyeing matters in the seed testa make the whole seed unsuitable for consumption, but they become edible after soaking and boiling in water. Tamarind seed is also used as raw material in the manufacture of polysaccharide (jellose), adhesive and tannin. Seeds and kernels are high in protein content, while the seed coat is rich in fiber and tannins (anti-nutritional factors). Seeds are gaining importance as an alternative source of proteins, and are besides a good source of fatty acids and rich in some essential minerals, such as Ca, P, Mg and K. 

Use Food products (margarine, hydrogenated shortenings) synthetic cocoa butter soaps cosmetics emulsions cotton dyeing synthetic detergents source of fatty acids, fatty alcohols, and methyl esters base for laundering and cleaning preparations for soft leathers. 

King KC, Adam PAJ, Laskowski DE, Schwartz R. Sources of fatty acids in the newborn. Pediatrics 1971 47 192-198. 

In addition to chylomicrons and VLDL as sources of fatty acids, fatty acids complexed to albumin are also supplied to the organs. The latter fatty acids are almost exclusively released by adipocytes when the body is in need of oxidizable and energy delivering substrates. Albumin displays a high affinity for fatty acids and one molecule of albumin can carry up to 6-8 fatty acid molecules. 

Serum and serum proteins have diverse functions which are now reasonably well understood for the industrially important cell lines, and which can generally be substituted by non-protein alternatives. Mammalian cells typically require a source of fatty acids, which were historically supplied by serum. To supply these, serum-free media usually contain plasma lipoprotein fractions, free fatty acids complexed to serum albumin or fatty acid/phospholipid microemulsions [61]. A high-density lipoprotein serum-fraction in medium containing bovine serum albumin was used by Seamans et al. [62] to replace serum in cultures of a recombinant antibody-producing GS-NSO cell line. Further, they found that the serum-fraction could be replaced with a commercially available non-protein-aceous lipid emulsion and a pluronic F-68/cholesterol emulsion. This gave equivalent growth and productivity (100 mg L ). 

The liver also plays a central role in lipid metabolism. When excess fuel is available, the liver synthesizes fatty acids. These are used to produce triglycerides that are transported from the liver to adipose tissues by very low density lipoprotein (VLDL) complexes. In fact, VLDL complexes provide adipose tissue with its major source of fatty acids. This transport is particularly active when more calories are eaten than are burned During fasting or starvation conditions, however, the liver converts fatty acids to acetoacetate and other ketone bodies. The liver cannot use these ketone bodies because it lacks an enzyme for the conversion of acetoacetate to acetyl CoA. Therefore the ketone bodies produced by the liver are exported to other organs where they are oxidized to make ATP. 

Triacylglycerols Source of fatty acids Affect neutral lipid droplet fluidity in foam cells Liquid crystalline — liquid neutral transformation of foam cell droplets... 

Soybean oil was not widely used for food until the 1930s, when oil-processing technologies advanced sufficiently to produce hydrogenated soybean oils with acceptable stability and flavor. Major industrial product uses for soybean oil today include paint and varnish, resins and plastics, and a source of fatty acids. The latter is often derived from refinery by-products (sometimes known as foots). 

FIGURE 21.1 The release of fatty acids for future use. The source of fatty acids can be a triacylglycerol (left) or a phospholipid such as phosphatidylcholine (right). 

---