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Storage. effect on selected characteristics and lipids of defatted soy flours
Author(s) -
Melton S. L.,
Movers R. E.,
Jaynes J. T.
Publication year - 1981
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/bf02659770
Subject(s) - chemistry , food science , linoleic acid , soy flour , silicic acid , fraction (chemistry) , lipoxygenase , chromatography , fatty acid , enzyme , biochemistry , organic chemistry
Three defatted soy flours (fully toasted, white and enzyme active) 92 days after production date were stored at 23 C for periods of 0, 60, 120 and 180 days. At each storage period, lipoxygenase activity, thiobarbituric acid number (TBA), Nitrogen Solubility Index (NSI) and total lipid were determined in 5 replications of each flour. The lipid was separated into 3 fractions by silicic acid column chromatography and the fatty acid composition of each fraction was determined by GLC. Lipids in each fraction were identified by TLC procedures. Toasted flour had the greatest amount of total lipid and lowest TBA of the flours and no lipoxy‐genase activity. Enzyme active soy flour had the highest NSI and the greatest lipoxygenase activity. During storage, lipoxygenase activity of enzyme active flour and TBA and total lipid of each flour de‐creased. Percentages of lipids in fraction I, II or III were different among the soy flours, and the percentages of lipids in fractions I and II changed during storage. In each lipid fraction during storage, linoleic acid decreased in toasted and white flours but remained constant in enzyme active flour. Linoleic acid in any lipid fraction of enzyme active flour was lowest of the soy flours.