Flavor Biochemistry

Abstract

This chapter outlines the chemistry of the substrate, the flavor precursors, and potential substrate, the γ-glutamyl peptides. Measurement of alliinase has usually been made by determining the substrate-dependent rate of production of pyruvate. The chapter looks at the flavor precursors, the S-alk(en)yl cysteine sulfoxides from the plants’ point of view. Their biosynthesis, localization within the plant, and their developmental and environmental regualtion are areas which have seen renewed research interest within the last decade. γ-Glutamyl peptides of amino acids and amines are very widely distributed in the plant kingdom, particularly in the Leguminosae and Alliaceae; more than 70 such peptides have been isolated. The high levels of cycloalliinin found in some plant extracts may result from alkaline conditions used in the extraction and purification. In order to circumvent the problem Granroth developed a method which used thin layer electrophoresis and chromatography in nonalkaline conditions to isolate and separate flavor precursors, amino acids, and peptides.