Influence of indigenous lactic acid bacteria on the volatile flavor profile of light-flavor Baijiu

Abstract

Baijiu (Chinese liquor) is a type of traditional distilled spirit drink produced by spontaneous fermentation. Lactic acid bacteria as the predominant bacteria during the fermentation of Baijiu may influence the flavor through the production of enzymes and metabolites. Results showed that there was significant difference in lactic acid bacteria counts between different fermentation periods. Indigenous lactic acid bacteria with high alcohol tolerance and esterase activity were selected for fortified fermentation. Inoculation with indigenous lactic acid bacteria significantly changed the flavor profile of Baijiu. All the selected strains promoted the formation of ethyl acetate which is an important flavor in Baijiu. Lactobacillus acetotolerans significantly promoted the formation of ethyl acetate, ethyl lactate, ethanol, acetic acid, and 2,4-di-tert-butylphenol. Sensory analysis revealed higher harmony in the samples fermented with L. hilgardii and L. acetotolerans, and higher intensive ester aroma in the samples fermented with L. planturum. The generation of flavors such as esters, alcohols and acids were species or even strain dependent. The results of this work will broaden our knowledge regarding the role of indigenous lactic acid bacteria during Baijiu manufacturing, and provide a potential approach for improving the flavor of Baijiu.