Changes in anthocyanins and volatile components of purple sweet potato fermented alcoholic beverage during aging.

Purple sweet potato was fermented into alcoholic beverage. By using LC-MS analysis, 12 types of anthocyanins were found in the purple sweet potato alcoholic beverage (PSPFAB); these were based on cyanidin and peonidin as aglycones. The anthocyanins in young PSPFAB mainly consisted of acylates. The acylated anthocyanins, however, degraded gradually with aging. Cyanidin 3-sophoroside-5-glucoside and peonidin 3-sophoroside-5-glucoside were found to be major anthocyanins in the PSPFAB after two years of aging. Moreover, 52 kinds of volatile components were detected in PSPFAB by GC-MS analysis. Alcohol and ester substances constituted a major proportion of these volatile components of PSPFAB. After two years of aging, levels of high-alcohols such as 1-pentanol remarkably decreased to below the detection limit, while the level of total esters increased significantly. Such variation of aromas enriched and improved the flavor of PSPFAB.