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Flavor improvement of soybean preparations by genetic removal of lipoxygenase‐2
Author(s) -
Davies C. S.,
Nielsen S. S.,
Nielsen N. C.
Publication year - 1987
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/bf02636994
Subject(s) - flavor , lipoxygenase , aroma , food science , isozyme , organoleptic , chemistry , taste , cultivar , polyunsaturated fatty acid , fatty acid , thiobarbituric acid , lipid oxidation , biology , biochemistry , enzyme , botany , lipid peroxidation , antioxidant
Abstract Lipoxygenase‐mediated oxidation of fatty acids has long been implicated in the production of off‐flavors in soybean products. This assumption was tested by use of preparations from soybean lines nearly isogenic to the cultivar Century that lack the lipoxygenase isozyme or isozyme combinations L 1 , L 2 , L 3 , L 1 + L 3 , or L 2 + L 3 . Near‐isogenic lines were used to ensure that any effects observed were due to elimination of lipoxygenase isozymes, and not to other unrecognized genetic differences between lines. Full‐fat soy flour and unblanched soymilk preparations from the lines were evaluated by a six‐member taste panel for eight flavor and/or aroma attributes common to soybeans. By comparison to near‐isogenic controls, removal of the L 2 isozyme from soymilk preparations produced significantly lower scores for beany, rancid and oily flavor and aroma attributes, as well as higher scores for dairy and cereal flavor and aroma attributes. Similar trends were noted for soy flour flavor attributes. Thiobarbituric acid (TBA) numbers, a measure of lipid oxidation, were lower in homogenized soy flour suspensions from lines lacking L 2 . Removal of the L 1 and L 3 isozymes did not result in improved flavor scores or lower TBA numbers. Total oil content and the fatty acid profile of the near isolines did not vary appreciably. The results indicated that genetic removal of the L 2 isozyme may reduce off‐flavors in soy products.