Effects of the high pressure homogenization on the viability of yeast cell and volatile components in non-pasteurized rice wine.

ABSTRACT

This study investigated the effects of high pressure homogenization (HPH) to replace a thermal pasteurization on the yeast cell inactivation and the volatile components of rice wine (RW). By applying HPH (172 MPa with 5 passes), the yeast count was reduced over 4 log cycles. The inactivation of yeast cells by HPH and a thermal processing, i.e. Holder pasteurization (HP), was quantitatively analyzed. In terms of the inactivation of yeast cells, the HPH at 172 MPa with 5 passes was equivalent to the HP at 65°C for 3 min. In RW, 34 volatile components were identified, including 8 alcohols, 18 esters, 2 acids, 1 carbonyls, 3 hydrocarbons, and 2 miscellaneous. Fruity volatiles were found more in HPH samples while components having fatty and oily characters were more detected in HP treated samples.