A simple photometric method for microdetermination of fatty acids in lipids
01 Sep 1969-Journal of the American Oil Chemists' Society (Springer-Verlag)-Vol. 46, Iss: 9, pp 473-475
TL;DR: A single step photometric micromethod for determination of fatty acids in lipids in benzene solution, using rhodamine 6G reagent, is developed and is applicable in the presence of glycerides, sterols, epoxy compounds, hydrocarbons and long chain hydroxy compounds such as long chain fatty alcohols.
Abstract: A single step photometric micromethod for determination of fatty acids in lipids in benzene solution, using rhodamine 6G reagent, has been developed. The method eliminates the disadvantage of formation of a biphasic system and is applicable in the presence of glycerides, sterols, epoxy compounds, hydrocarbons and long chain hydroxy compounds such as long chain fatty alcohols. The long chain fatty acids from C12 to C22, both saturated and unsaturated, can be determined with reasonable accuracy in the concentration range of 0.08–0.25 µmole/ml. The method is simple, rapid, and requires relatively inexpensive chemicals.
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TL;DR: Fish muscle lipolysis is presented in the context of basic fish muscle physiology and lipid composition and phospholipase A and lipases from fish muscle have been described and characterized.
Abstract: Lipolysis occurs extensively in fish muscle post-mortem and is associated with quality deterioration in the frozen tissue. Fish muscle lipolysis is presented in the context of basic fish muscle physiology and lipid composition. Phospholipase A and lipases from fish muscle have been described and characterized. The reaction is usually followed by measurement of free fatty acid production, and several colorimetric assays are available. Processing and storage treatments have been shown to influence the extent and rate of lipolysis in fish muscle; most of the research in this area has been directed at the effects of frozen storage. The interaction of lipolysis and lipid oxidation is a particularly intriguing area of study as triglyceride hydrolysis leads to increased oxidation while phospholipid hydrolysis produces the opposite effect.
121 citations
TL;DR: A rapid, dose-dependent effect of TCDD, was the elevation of levels of organic-soluble fluorescent pigment in the heart, which was found to match a previously characterized fraction of lipofuscins in fluorescence spectrum and chromatographic properties.
93 citations
TL;DR: A rapid and sensitive spectrophotometric assay for free fatty acids using rhodamine 6G dye base in benzene as a fatty acid indicator is described, finding negligible to moderate interference by methyl stearate, phosphatidylcholine, cholesterol, partially purified spinach galactolipids, and spinach subchloroplast particle pigments.
56 citations
TL;DR: Differential proteolytic sensitivity of different oleosins in the oil body membranes could be a determinant of oil body longevity during seed germination and accompanying lipid mobilization.
Abstract: Until now, there has been no conclusive demonstration of any in vivo oleosin degradation at the early stages of oil body mobilization. The present work on sunflower (Helianthus annuus L.) has demonstrated limited oleosin degradation during seed germination. Seedling cotyledon homogenization in Tris-urea buffer, followed by SDS-PAGE, revealed three oleosins (16, 17.5 and 20 kDa). Incubation of oil bodies with total soluble protein from 4-day-old seedlings resulted in oleosin degradation. In vitro and in vivo degradation of the 17.5-kDa oleosin was faster than the other two, indicating its greater susceptibility to proteolysis. Oleosin degradation by the total soluble protein resulted in a transient 14.5-kDa polypeptide, followed by an 11-kDa protease-protected fragment, which appeared post-germinatively and accumulated corresponding to increased rate of lipid mobilization. A 65-kDa protease, active at pH 7.5-9.5, was zymographically detected in the total soluble protein. Its activity increased along with in vivo accumulation of the protease-protected fragment during seed germination and accompanying lipid mobilization. Protease-treated oil bodies were more susceptible to maize lipase action. Differential proteolytic sensitivity of different oleosins in the oil body membranes could be a determinant of oil body longevity during seed germination.
49 citations
TL;DR: The lipid composition of the earthwormLumbricus terrestris has been reexamined under conditions intended to avoid enzymatic and chemical alterations during storage, extraction, and fractionation procedures, and it is concluded that these acids were synthesized in the worms.
Abstract: The lipid composition of the earthworm Lumbricus terrestris has been reexamined under conditions intended to avoid enzymatic and chemical alterations during storage, extraction, and fractionation procedures. The simple lipids included aliphatic hydrocarbons, steryl esters, glycerides, and at least nine different sterols, all thought to be derived from the diet. Free fatty acids, previously considered to be major components of worm lipids, comprised only 0.3% of the total lipid weight. Phospholipids included (in order of relative abundance) phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, and phosphatidylinositol, as well as sphingomyelin. Glycolipids included cerebrosides and sulfatides containing both glucose and galactose, and gangliosides containing glucosamine and sialic acid. The fatty acid compositions of these lipid classes appeared to be a mixture of what are considered typical plant, bacterial, and animal acids. Several fatty acids found in the worms, including cis-vaccenic and eicosapentaenoic acids, were essentially absent from the dietary components, and it is concluded that these acids were synthesized in the worms. The earthworm derives much of its lipid adventitiously, but exerts at least some control over its tissue lipid composition.
39 citations
References
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882 citations
TL;DR: In this article, a colorimetric ultramicro method for the determination of serum and tissue fatty acids has been improved in sensitivity and selectivity by extracting cobalt rather than copper soaps by means of a solvent lighter than water instead of chloroform.
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TL;DR: The colorimetric method for FFA extraction compares well with previous methods in sensitivity and accuracy, and offers advantages in speed, simplicity, and possibly specificity.
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TL;DR: In this article, two colorimetric methods of estimating the higher fatty acids C 7 -C 18 have been developed, one involves the formation of the copper soap and the other the cobalt soap.
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