Stereoisomeric Flavor Compounds. 72. Stereoisomeric Distribution of Some Chiral Sulfur-Containing Trace Components of Yellow Passion Fruits

The enantiomeric distributions of cis- and trans-2-methyl-4-propyl-1,3-oxathiane and 3-mercaptohexyl acetate and butanoate in passion fruit extracts were determined by means of multidimensional gas chromatography (MDGC) using sulfur-selective detection. 4S-configured oxathianes and S-configured 3-mercaptohexyl alkanoates of high enantiomeric purity were detected. 2,2-Dimethyl-4-propyl-1,3-oxathiane and 3-mercaptohexyl propanoate were used as internal standard components, allowing a quantification of the volatiles investigated. The trace components were found in a range from less than 0.5 to 18 ppb. The results are discussed with regard to the biosynthesis of these volatiles. Due to the high enantiomeric purities detected, the differentiation between naturally occurring flavor compounds and synthetic racemates added to passion fruit products is realized conclusively.