Biochem Lab Assignment

420 Words2 Pages
Maxine Alexandra G. Merin February 4, 2014 BSMT-2C Principles Solubility Test: The test is based on the property of solubility of lipids in organic solvents and insolubility in water. The oil will float on water because of lesser specific gravity Reaction to Iodine to test for unsaturation of fatty acids: The unsaturated fatty acids absorb iodine at the double bonds until all the double bonds are saturated with iodine. Hence the amount of iodine required to impart its color to the solution is a measure of the degree of the fatty acids. Chloroform dissolve sample give red color which decolorizes the iodine giving brown color. This indicates the presence of fatty acids. Test for Rancidity (kreis kerr): Kreis kerr test is a qualitative test for the presence of aldehydes and ketones in fats and oils, created by its rancidity. The term "rancidity" is used to describe the development of bad flavors and odors in fats and oils. It may result either from hydrolysis of the triacylglycerol present in fats and oils or from oxidation of the unsaturated fatty acids present in the triacylglycerol. The former cause may be detected by an increase in the acid value of the sample. Auto oxidation at fatty acid double bonds occurs by reaction with molecular oxygen present in the atmosphere, causing the formation of labile peroxides. The peroxides formed during auto oxidation are unstable and decompose into free radicals .These initiate chain reactions which lead to eventually to decomposition of the fatty acid into various low molecular weight aldehydes and ketones. Aldehydes and ketones react with phloroglucinol developing a red color which would mean that the oil is rancid Emulsification of Oil: When oil and water, which are immiscible, are shaken together, the oil is broken up into very tiny droplets which are dispersed in water. This is known as oil in

More about Biochem Lab Assignment

Open Document