Deterioration of Lemon Flavor

Part I Deterioration of citral

Abstract

By mixing lemon oil into lemon juice of pH 2.4, an unpleasant odor was developed within several days, and citral content decreased very rapidly during the period. Commercial citral showed similar changes in lemon juice and in buffers of various organic acids. The decrease of citral was very rapid below pH 4, while it was much slower in the neutral region. These changes were not affected by presence of glucose, fructose, sucrose, sorbit, sodium benzoate, and no difference was observed between storages under air and nitrogen. One of the nine peaks on gaschromatogram of deteriorated citral in acid solution was identified as p-cymene, and one unidentified peak fraction obtained by its column chromatography was found to have the odor mentioned above.