Optimization of Brewing Process of Low-Alcohol Litchi Wine and its Influence on Volatile Compounds

The optimization of low-alcohol litchi wine brewing process through orthogonal design L9(34) and the comparison of influence of pre- and post-fermentation on the volatile compounds by using gas chromatography-mass spectrometry (GC–MS) analysis were studied. The low-alcohol litchi wine which fermented using the mixed aroma-producing yeastsKloeckera apiculata(Y2) andHansenula anomala(Hansen) H. et P. Sydow (Y4) at 14°C, with ratio Y2/Y4 of 1:2 (vol.) and inoculum size of 4 (%,vol.), had the typical characteristics of low alcohol, light yellow color, fresh litchi-like and refined wine aroma, refreshing sweet taste. The volatile compounds of the fermented wine invented a marked improvement in flavor of the low-alcohol litchi wine, because the esters were increased 1.16-fold, alcohols (0.96-fold), acids (2.38-fold), while the terpenes decreased more than 39% compared with samples before fermentation. The results would explain the technological differences and superiorities in the aroma compounds contributed by the aroma-producing yeasts.