Lipid Changes During Processing and Storage of Sweet Potato Flakes

Abstract

Changes in fatty acids, lipid classes, and total lipids, during processing and storage of Isweet potato flakes were identified and quantified. The extracted and purified lipids were separated by column chromatography hito three major classes: neutral lipids, glycolipids and phospholipids. The fatty acids of each class were determined. During processing and storage, the percent of the total lipids decreased significantly. The percent of the unsaturated fatty acids, linolenic and palmitoleic, decreased significantly while the percent of the saturated fatty acids, palmitic and stearic, increased slightly.The decrease in the unsaturation ratio following, the 6-and 12-months storage for sweet potato flakes, suggests the existence of a link between the decrease in unsaturates and the development of off-flavor and odor.

Structure of Cell Wall Polysaccharide Isolated from Cotyledon of Tora-bean (Phaseolus vulgaris)

“…The analysis of fatty acids was performed with a Shimadzu Mass Spectrometer, model GC-MS-7000, using a glass column (2 m of length) packed with OV-l at 180°C after conversion into corresponding methyl esters. 22 ) Hydrolysis of the alkali-insoluble polysaccahride was performed in a sealed tube with 72 % sulfuric acid at 100°C for 1 min, and after dilution with water to a final concentration of 2 M sulfuric acid, hydrolysis was continued by heating at 100°C for 6 hr. Hydrolysis of the methylated polysaccharide was achieved first by heating with 90% formic acid for 15 hr at 100°C.…”