Gilbert, Laura Marcella2014-03-142014-03-141977-12-15etd-07282010-020132http://hdl.handle.net/10919/43937L to D isomerization of amino acids in a commercially prepared alkali-treated food-grade soy isolate was investigated. A soy flour product was also investigated as a control which had not been alkali treated. Methionine and valine collected from two soy flour and two soy isolate samples were coupled with L-leucine-N-carboxyanhydride. If both D- and L-forms were present this would produce diastereomeric dipeptide derivatives. The derivatives were separated by ion-exchange chromatography using a TSM Amino Acid Analyzer. Comparison of the sample methionine and valine dipeptide peaks to standard dipeptide peaks revealed the presence of L-valine, L-methionine and D-methionine in both soy flour and soy isolate samples. Methionine was substantially isomerized in both products. D-valine was not observed in either soy flour or soy isolate samples. Thus, isomerization of methionine appeared to occur at a faster rate than valine. Acid hydrolysis, toasting of soy meal, and alkaline treatment are all conditions which may be responsible for the isomerization of methionine.vi, 72 leavesBTDapplication/pdfIn Copyrightalkaline treatmenttoasting of soy mealisomerization of methionineL-methionine and D-methionineLD5655.V855 1977.G535Thesishttp://scholar.lib.vt.edu/theses/available/etd-07282010-020132/