Changes in Proanthocyanidin Content during the Processing of Umeshu, a Spirit-Based Liqueur of Japanese Apricot (Prunus mume Sieb. et Zucc.) Fruit

Japanese apricot (Prunus mume Sieb. et. Zucc.), also known as Ume, is used as a food item and a folk remedy in most east Asian countries, including Japan. Umeshu is a liqueur made from Ume and is one of the most popular products obtained from this fruit. The polyphenols (PPs) and proanthocyanidins (PAs) present in Umeshu and the residual fruit obtained post immersion were analyzed. We are the first to report the characteristics of the phenolic compounds obtained during the processing of Umeshu. The concentration of PA in Umeshu was approximately 16 mu g/mL, and this concentration was significantly lower than the concentrations of PA present in other liqueurs. It is believed that most of the PAs contained in Umeshu leach out from the endocarp. The total amounts of extractable PAs decreased, and the total amounts of nonextractable PAs increased in Umeshu and the residual fruit during the processing stage.