Impact of solid-state saccharification on the flavor of rice-flavor baijiu

Rice-flavor baijiu is a traditional Chinese liquor. The flavor profile and volatiles presented with or without the solid-state saccharification (SSS) were investigated to reveal the effects of SSS process on the quality of rice-flavor baijiu. The liquor prepared with SSS had a sweet flavor. It contained significantly higher contents of β-phenylethyl alcohol, β-phenylethyl acetate, and ethyl lactate with odor active value of >1. The liquor prepared without SSS had a cheese-like flavor. It was confirmed that the cheese-like flavor derived from butanoic acid was only detected in the liquor prepared without SSS. SSS facilitated the biosynthesis of β-phenylethyl alcohol and ethyl lactate by supplying a large amount of phenylalanine and lactic acid at the initial stage of fermentation, and it prevented contamination. These results indicated that the SSS process contributed to produce the characteristic flavor compounds of rice-flavor baijiu. PRACTICAL APPLICATION: Solid-state saccharification (SSS) process of rice-flavor baijiu contributes not only in brewing, but also in the production of the characteristic flavor compounds and the repression of the off-flavor derived from the contamination. Therefore, SSS is a critical process to control the flavor of rice-flavor baijiu.