Effect of the Ripening Condition of Japanese Apricot (Prunus mume) ‘Nanko’ Fruit on the Aroma and Bitter Components of Its Processed Liqueur

Abstract

Effects of harvest time and storing conditions after harvest on the aroma and bitter components of processed Japanese apricot liqueur (ume liqueur) were investigated with Japanese apricot (Prunus mume Sieb. et Zucc.) ‘Nanko’. Some of the aroma components in ume liqueur were identified as γ-decalactone, d-decalactone, ethyl butyrate and butyl acetate by the sniffing test. Content of these aroma components in ume liqueur was higher in fruit harvested later, and was high when the harvested fruit were stored for four days at 20°C or three days at 30°C. Ume liqueur made from fruit stored within five days at 20°C or within three days at 30 or 35°C showed equal or lower content of ethyl benzoate, exhibiting immature flavors, than that made from fruit immediately after harvest. Content of prunasin and oxalic acid that exhibited bitterness in ume liqueur decreased when the fruit was stored for four days at 20°C or three days at 30°C. These results suggest that aroma and bitter components in ume liqueur are influenced by the harvest time and storing conditions, and mature fruit should be harvested and the fruit stored for four days at 20°C or three days at 30°C before processing in order to increase aroma components and decrease bitter components.