浓香型白酒窖泥产酸菌协同发酵条件优化

Optimization of Synergistic Fermentation Conditions of Acid Producing Bacteria in Luzhou-flavor Liquor Mud

浓香型白酒中己酸和丁酸的含量影响着己酸乙酯和丁酸乙酯的含量,从而影响白酒的风味。为提高浓香型白酒中己酸和丁酸的含量,本文以特基拉芽孢杆菌(Bacillus tequilensis)、空气芽孢杆菌(Bacillus aerius)、丁酸梭菌亚种(Clostridium butyricum subsp)3株窖泥产酸功能菌进行协同发酵;并将协同发酵产酸效果较好的SJ-1、SJ-3、SJ-8和优质窖泥富集菌液等量接种进行协同发酵,利用单因素试验优化其协同发酵产己酸和丁酸的发酵条件;通过部分因子试验、最陡爬坡试验和Box-Behnken响应面试验设计模型优化己酸和丁酸的发酵培养基。优化结果为:接种量3%、培养温度28℃、发酵时间12 d、pH 6.4、蛋白胨5.10 g/L、乙酸钠5.04 g/L和丁酸钠4.45 g/L,在此条件下己酸和丁酸产量分别为1156.21 mg/100 mL、2345.84 mg/100 mL,比优化前提高了3.32倍、3.22倍。本研究以期为提高白酒风味物质和窖池养护提供理论依据。

The content of hexanoic acid and butyric acid in Luzhou-flavor liquor affects the content of ethyl caproate and ethyl butyrate,which affected the flavor of liquor.In order to increase the content of hexanoicacid and butyric acid in Luzhou-flavor liquor,three strains of Bacillus tequilensis,Bacillus aerius,and Clostridium butyricum subsp were used in this paper.The acid-producing functional bacteria carry out cooperative fermentation;SJ-1,SJ-3,SJ-8 and high-quality pit mud-enriched bacteria liquid were inoculated in equal amounts for cooperative fermentation,and single-factor test were used to optimize the fermentation conditions of synergistic fermentation broth to produce hexanoic acid and butyric acid.The fermentation medium of hexanoic acid and butyric acid was optimized by fractional factorial designs,the steepest climbing test and the Box-Behnken test design model in response surface method.The optimized results were,inoculum volume 3%,culture temperature 28℃,fermentation time 12 d,pH 6.4,peptone 5.10 g/L,sodium acetate 5.04 g/L and sodium butyrate 4.45 g/L.Under these conditions,the output of hexanoic acid and butyric acid were 1156.21 mg/100 mL、and 2345.84 mg/100 mL,which were 3.32 times and 3.22 times higher than before optimization.This research aims to provide a theoretical basis for improving the flavor substances of liquor and the maintenance of pits.