Abstract: Sweet potato puree was obtained from sweet potato by peeling, pulping and liquefaction, and saccharified after addition of gelatinized malt for wine production. By one-factor-at-a-time method, fermentation temperature, inoculum size of yeast and initial pH were chosen as the major factors for further optimization by mathematical modeling using Box- Behnken design and response surface analysis. The contents of alcohol and total esters were selected as response variables. The optimal fermentation conditions were determined as follows: initial sugar content, 24%; inoculum size of active dry yeast, 0.15%; and initial pH, 4.0. Under these optimal conditions, the contents of alcohol and total esters were 14.25% and 372.41 mg/L, respectively. Fifty-four aroma compounds were identified from sweet potato wine, mainly including alcohols and esters. The wine had a uniform golden color and its flavor was identical to that of both sweet potato and wheat malt.

Key words: sweet potato wine, process optimization, alcohol content, total esters, aroma components