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Free fatty acids, Determination

Free Fatty Acids Determine as directed under Free Fatty Acids, Appendix VII, using the following equivalence factors (e) in the formula given in the procedure ... [Pg.119]

Free Fatty Acids Determine as directed under Free Fatty Acids, Appendix VII. [Pg.386]

NSselund, B. M. A., Berastrom, K., Lundin, A., and Amer, P., Free fatty acid determination by peroxidase catalyzed luminol chemiluminescence. J. Biotumin. Chemitumin. 3, 115-124 (1989). [Pg.174]

To reduce the melting point of a tallow-rapeseed oil mixture, the triglyceride composition of the mixture was altered by enzymatic interesterification in a solvent-free system. The interesterification and hydrolysis were followed by melting point profiles and by free fatty acid determinations. The degree of hydrolysis was linearly related to the initial water content of the reaction mixture. The rate of the interesterification reaction was influenced by the amount of enzyme but not much by temperature, between 50°C and 70°C. The melting point reduction achieved by interesterification depended on the mass fractions of the substrates the lower the mass fraction of tallow, the larger the reduction of the melting point. ... [Pg.149]

Consumer acceptance of milk is strongly determined by its sensory characteristics. The development of off-flavor in milk as a result of lipolysis can reduce the quality of milk. The enzymatic release, by milk lipase, of free fatty acids (FFA) from triglycerides causes a flavor defect in milk described as rancid . Triglycerides in milk contain both long chain and short chain fatty acids, which are released at random by milk lipase. The short chains FFA, like butyric acid, are responsible for the off-flavor. [Pg.172]

The purity of the product was determined by the checkers by GLC analysis using the following column and conditions 3-nm by 1.8-m column, 5% free fatty acid phase (FFAP) on acid-washed chromosorb W (60-80 mesh) treated with dimethyldichlorosilane, 90 C (1 min) then 90 to 200 C (15°C per rain). The chromatogram showed a major peak for methyl 2-methyl-l-cyclohexene-l-carboxylate preceded by two minor peaks for methyl 1-cyclohexene-l-carboxylate and l-acetyl-2-methylcyclohexene. The areas of the two impurity peaks were 5-6% and 0.5-2% that of the major peak. The purity of the product seems to depend upon careful temperature control during the reaction. The total amount of the two impurities was 14-21% in runs conducted at about -15 to -20°C or at temperatures below -23°C. [Pg.20]

Ketogenesis is regulated at three cmcial steps (1) control of free fatty acid mobihzation from adipose tissue (2) the activity of carnitine palmitoyltransferase-1 in hver, which determines the proportion of the fatty acid flux that is oxidized rather than esteri-fied and (3) partition of acetyl-CoA between the pathway of ketogenesis and the citric acid cycle. [Pg.189]

The free fatty acid uptake by tissues is related directly to the plasma free fatty acid concentration, which in turn is determined by the rate of lipolysis in adipose tissue. After dissociation of the fatty acid-albumin complex at the plasma membrane, fatty acids bind to a membrane tty acid transport protein that acts as a transmembrane cotransporter with Na. On entering the cytosol, free fatty acids are bound by intracellular fatty acid-binding proteins. The role of these proteins in intracellular transport is thought to be similar to that of serum albumin in extracellular transport of long-chain fatty acids. [Pg.207]

Using PTLC six major fractions of lipids (phospholipids, free sterols, free fatty acids, triacylglycerols, methyl esters, and sterol esters) were separated from the skin lipids of chicken to smdy the penetration responses of Schistosoma cercaria and Austrobilharzia variglandis [79a]. To determine the structure of nontoxic lipids in lipopolysaccharides of Salmonella typhimurium, monophosphoryl lipids were separated from these lipids using PTLC. The separated fractions were used in FAB-MS to determine [3-hydroxymyristic acid, lauric acid, and 3-hydroxymyristic acids [79b]. [Pg.320]

The restricted shelf life of liquid milk continues to be a problem that is often more influenced by the type of milk being sold rather than the pasteurisation technique. The shelf life of processed milk is determined primarily by the quality of the raw milk from the dairy herd. Increasing cell counts in the milk and a higher concentration of free fatty acids, contribute to rancidity in both liquid milk and milk products. Janzen (1972) reported that the 0-14 day shelf life of pasteurised milk is influenced by the somatic cell concentration in the raw milk and found that after 14 days any observed changes in the flavour and stability of the milk were attributable to microbial activity during storage. [Pg.104]

Some of these tests cover very broadly the general chemical makeup of waxes. Constants such as acid, ester, saponification and iodine numbers can be used to identify, differentiate or classify waxes chemically (Ref 59). Specific tests are used to determine the values of these numbers for waxes. The saponification number generally indicates the total quantity of both esters and free acids in a wax. The acid value is an indication of the quantity of free fatty acids. The ester value is the relative quantity of esters... [Pg.355]

Koops, J. and Klomp, H. 1977. Rapid colorimetric determination of free fatty acids (lipol-ysis) in milk by the copper soap method. Neth. Milk Dairy J. 31, 56-74. [Pg.271]

Kuzdzal-Savoie, S. 1980. Flavour impairment of milk and milk products due to lipolysis. VII. Determination of free fatty acids in milk and milk products. Int. Dairy Fed. Bull. 118, pp. 53-66. [Pg.272]

Novak, M. 1965. Colorimetric ultramicro method for the determination of free fatty acids. J. Lipid Res. 6, 431-433. [Pg.273]

Pillay, V. T., Myhr, A. N. and Gray, J. L. 1980. Lipolysis in milk. I. Determination of free fatty acid and threshold value for lipolyzed flavor detection. J. Dairy Sci. 63, 1213-1218. [Pg.274]

Salih, A. M. A. and Anderson, M. and Tuckley, B. 1977. The determination of short and long chain free fatty acids in milk. J. Dairy Res. 44, 601. [Pg.275]

The surface tension of milk is on the order of 50 dynes cm-1 at 20°C, compared to that of water, which is 72.75 dynes cm-1 at the same temperature. The milk proteins, milk fat, phospholipids, and free fatty acids are the principal surface-active components determining the surface properties of milk. [Pg.430]

Commercial crude lecithin is a hrown to light yellow fatly substance with a liquid to plastic consistency. Its density is 0.97 g/niL (liquid) and 0.5 g/mL (granule). The color is dependent on its origin, process conditions, and whether it is unbleached, bleached, or Altered. Its consistency is determined chiefly by its oil. free fatty acid, and moisture content. Properly refined lecithin has practically no odor and has a bland taste. It is soluble in aliphatic and aromatic hydrocarbons, including the halogenated hydrocarbons however, it is only partially soluble in aliphatic alcohols. Pure phosphatidylcholine is soluble in ethanol,... [Pg.926]

Kwon, D.Y. and Rhee, J.S. 1986. A simple and rapid colorimetric method for determination of free fatty acids for lipase assay. J. Am. Oil Chem. Soc. 63 89-92. [Pg.383]

This unit defines three different tests that are used to evaluate lipid systems. The first two, i.e., iodine value (IV see Basic Protocol I) and saponification value (SV see Basic Protocol 2), are used to determine the level of unsaturation and the relative size (chain length) of the fatty acids in the system, respectively. The free fatty acid (FFA) analysis (see Basic Protocol 3) is self-explanatory. Each of these analyses provides a specific set of information about the lipid system. The IV and SV provide relative information this means that the data obtained are compared to the same data from other, defined lipid systems. In mixed triacylglyceride systems there is no absolute IV that indicates the exact number of double bonds or SV that indicates the exact chain length. The data from the FFA analysis is an absolute value however, the meaning of the value is not absolute. As a quality indicator, ranges of FFA content are used and the amount that can be tolerated is product and/or process dependent. [Pg.467]

Table D1.4.2 Sample Weights and Alcohol Volumes for Determination of Free Fatty Acid Content in Fats and Oils... Table D1.4.2 Sample Weights and Alcohol Volumes for Determination of Free Fatty Acid Content in Fats and Oils...

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See also in sourсe #XX -- [ Pg.117 ]




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