Comparison of Methods for Determination of Lysine in Cereals

Abstract The lysine contents of 10 milled wheat products and cereal foods were determined by microbiological, enzymatic, two-dimensional paper chromatographic, and ion exchange chromatographic methods. The assay of lysine by two-dimensional paper chromatography produced very low results. The results from the microbiological method were comparable to those by the ion exchange method. The decarboxylase method consistently gave low results which averaged 82% of those obtained by the microbiological assay. Possible reasons for these low results are presented and discussed.