威宁豆酱纯种发酵工艺优化及挥发性风味物质分析

采用枯草芽孢杆菌（Bacillus subtilis）DX-9和异常威克汉姆酵母菌（Wickerhamomyces anomalus）DZ-3分别发酵制备威宁豆酱，以氨基酸态氮含量和感官评分为评价指标，优化制曲条件、辅料添加量及后发酵条件，并采用气相色谱-质谱联用（GC-MS）技术检测豆酱中的挥发性风味物质。结果表明，菌株DX-9和DZ-3的最佳制曲条件：接种量2%和3%、温度38 ℃和34 ℃、时间12 d和18 d；辅料最适添加量：食盐10%、辣椒5%、五香粉1.5%；菌株DX-9和DZ-3的最佳后发酵条件：温度40 ℃和36 ℃、时间均为90 d。纯种发酵豆酱的品质优于自然发酵豆酱，且菌株DX-9比DZ-3发酵的豆酱品质更佳。自然发酵、菌株DX-9和DZ-3发酵豆酱中挥发性风味物质分别检出73、50和64种，共有物质为23种，主要风味物质分别为醇类（27.36%）、酸类（75.68%）和烯烃类（64.21%）。通过主成分分析（PCA）得出威宁豆酱主要挥发性风味物质为烃类和酸类。

Optimization of pure-culture fermentation process and volatile flavor compounds of Weining soybean paste

Weining soybean paste were made by Bacillus subtilis DX-9 and Wickerhamomyces anomalus DZ-3, respectively fermentation. The koji-making conditions, auxiliary materials addition and post-fermentation condition were optimized using amino acid nitrogen content and sensory evaluation as evaluation indicators. The volatile flavor substances in Weining bean paste were determined by GC-MS. The results showed that the optimal koji-making conditions for strains DX-9 and DZ-3 were inoculum 2% and 3%, koji-making temperature 38 ℃ and 34 ℃, and time 12 d and 18 d, the optimal auxiliary materials additions were salt 10%, pepper 5%, and five-spice powder 1.5%, and the optimal post-fermentation conditions for strains DX-9 and DZ-3 were temperature 40 ℃ and 36 ℃, and time 90 d. The quality of pure-culture fermented soybean paste was better than that of natural fermented soybean paste, and the quality of soybean paste fermented by strain DX-9 was better than that fermented by strain DZ-3. There were 73, 50, and 64 volatile flavor substances detected in natural fermentation, strain DX-9 and DZ-3 fermented soybean paste, respectively. There were 23 common substances, and the main flavor substances were alcohols (27.36%), acids (75.68%), and olefins (64.21%), respectively. Through principal component analysis (PCA), it is concluded that the main volatile flavor substances in Weining soybean paste were hydrocarbons and acids.