高盐稀态酱醪中功能性酵母菌的筛选、鉴定及发酵特性

Screening,Identification and Fermentation Characteristics of Functional Yeasts from High-salt Liquid-state Moromi

从高盐稀态酱醪中筛选酵母菌株,其中14株分离鉴定的酵母菌株可分为4个菌种,选择代表性菌株进行生理生化鉴定并探究其生长特性,并将分离的14株酵母菌单独发酵产香,结合气相色谱-质谱和嗅闻感官评价,探究各菌株对酱油风味的功能作用。结果表明,胶红酵母和似平滑假丝酵母对酱油风味具有一定的提升效果,可能与2-苯乙酸乙酯、3-甲硫基-1-丙醇、2,6-二甲基吡嗪等物质含量的增加相关,为潜在风味功能酵母。而粉状米勒氏酵母和近平滑假丝酵母对酱油风味具有负面影响,特别是粉状米勒氏酵母,菌落表面干燥褶皱,其繁殖代谢将大幅提高酱油中2-辛酮、2-壬酮和1,2,3-三甲氧基苯的含量,带来明显的不良风味,是酱油风味的有害酵母。本研究明确了4种不同酵母菌对酱油风味的作用差异,对酱油发酵的风味调控具有指导意义。

A total of 14 yeast strains were isolated from high-salt liquid-state moromi and identified into four species.Representative strains were selected for physiological and biochemical identification and evaluation of growth characteristics.Moreover,these strains were individually used to ferment soy sauce to explore their effects on flavor soy sauce by gas chromatography-mass spectrometry(GC-MS)detection and sensory evaluation.The results showed that Rhodotorula mucilaginosa and Candida metapsilosis,potential flavor-producing strains,could improve the flavor of soy sauce by producing more 2-phenethyl acetate,3-methylthio-1-propanol and 2,6-dimethylpyrazine.However,Millerozyma farinose and C.parapsilosis had negative impacts on soy sauce flavor.Notably,M.farinose,forming colonies with a dry and wrinkled surface,could obviously increase the contents of 2-octanone,2-nonanone and 1,2,3-trimethoxybenzene to produce an intense off-flavor.The findings of this study are meaningful for guiding flavor regulation during soy sauce fermentation.