从日式高盐稀态发酵酱油酱醪中分离获得一株能转化阿魏酸(ferulic acid,FA)生成4-乙烯基愈创木酚(4-vinylguaiacol,4-VG)和 4-乙基愈创木酚(4-ethylguaiacol,4-EG)的酵母菌株 JLY60-1,通过ITS rDNA测序和同源序列检索分析鉴定为W ickerham iella ver sat ili s,其最适生长温度为30 ℃,在20%盐浓度下培养15 d,发酵液中的4-EG浓度最高,达13.6 mg/L.在传统酱油酿造过程中强化菌株JLY60-1,采用高效液相色谱法和离子迁移色谱法测定不同发酵酱醪中酚酸及挥发性风味组分的含量,结果表明,菌株JLY60-1可以高效转化酱醪中的FA生成4-VG和4-EG,发酵30 d的酱油中4-VG和4-EG含量分别达到16.5,30.5 mg/L,对照组含量分别为1.83,3.03 mg/L.同时,强化菌株JLY60-1还提高了酱油中醛类、酮类芳香化合物的含量,丰富了酱油香气,对改善和提升酱油品质具有重要实用价值.
Screening of Guaiacol-Producing Strains and Their Application in Soy Sauce Brewing
A yeast strain JLY60-1 that can convert ferulic acid(FA)into 4-vinylguaiacol(4-VG)and 4-ethylguaiacol(4-EG)is isolated from Japanese-style high-salt dilute fermented soy sauce mash.It is identified as Wickerhamiella versatilis by ITS rDNA sequencing and homologous sequence retrieval and analysis.The optimal growth temperature is 30 ℃,and when it is cultured at 20%salt concentration for 15 days,the concentration of 4-EG in the fermentation broth is the highest of 13.6 mg/L.In the traditional soy sauce brewing process,the strain JLY60-1 is strengthened.The content of phenolic acids and volatile flavor components in different fermented soy sauce mashes are determined by high-performance liquid chromatography and ion migration chromatography.The results show that the strain JLY60-1 could efficiently convert FA in soy sauce mash into 4-VG and 4-EG,and the content of 4-VG and 4-EG in soy sauce fermented for 30 days reaches 16.5,30.5 mg/L respectively,compared to 1.83,3.03 mg/L respectively in the control group.At the same time,the strengthened strain JLY60-1 also increases the content of aldehyde and ketone aromatic compounds in soy sauce,enriches the aroma of soy sauce,and has important practical value for improving the quality of soy sauce.