Abstract
The so-called “lemon-shu” prepared by immersing lemon slices in white liquor showed the deterioration in flavor during storage for several days. The flavor fraction extracted with hexane examined by gas chromatography. p-Cymene, 2-p-tolyl-propene and 2-p-tolyl-2-ethoxypropane were detected as factors responsible for the deterioration flavor, although 2-p-tolyl-2-propanol was not detected. Since citral was expected to be their precursor, it was removed from the lemon oil by the aluminum oxide treatment. This citral-free lemon oil showed no changes in flavor, even when it was stored in the citric acid solution for three weeks. After that, pcymene-like odor was gradually increased, but no deterioration products from citral were detected by gas chromatography. The untreated lemon oil added in the citric acid solution gave off an unpleasant odor within several days of the storage. p-Cymene, 2-p-tolyl-propene, 2-p-tolyl-2-ethoxypropane and 2-p-tolyl-2-propanol were apparently detected as the deterioration products from this lemon oil itself.
