郫县豆瓣生香酵母的筛选及生长特性

Screening of Aroma-Producing Yeast from Pixian Broadbean Paste and Optimization of Its Growth Condition

生香酵母对郫县豆瓣发酵过程中风味的形成具有重要意义,作者从传统郫县豆瓣甜瓣子中分离获得酵母菌菌株,通过产醇、产香试验筛选产风味能力较强的菌株,并研究其在不同氯化钠质量分数、pH和温度条件下的生长情况。结果显示,从传统郫县豆瓣中分离获得了28株酵母菌,主要为鲁氏接合酵母(Zygosaccharomyces rouxii),也包括奥默柯达酵母(Kodamaea ohmeri)、库德里阿兹威氏毕赤酵母(Pichia kudriavzevii)、酿酒酵母(Saccharomyces cerevisiae)和伯顿丝孢毕赤酵母(Hyphopichia burtonii)。所有菌株中,鲁氏接合酵母菌株BP02产醇、产香能力相对较强,该菌株最高可耐受含有质量分数20%氯化钠的培养环境,在pH值为3~8、培养温度为10~37℃条件下均可生长,其在含质量分数5%氯化钠、pH值为4~6、温度为37℃时生长最旺盛。总体来看,鲁氏接合酵母是传统郫县豆瓣最主要的酵母,本研究中筛选出的生香鲁氏接合酵母BP02在高盐、微酸、中温的培养条件下可生长良好,适用于郫县豆瓣发酵与后熟过程中作为强化菌剂添加,以达到提高郫县豆瓣感官品质的目的。

Aroma-producing yeasts play an important role in the flavor formation of Pixian bean paste.In the study,yeast strains were screened from traditional Pixian bean paste and a strain with prominent alcohol and aroma-producing abilities was selected for further investigation of its growth characteristics under different salt concentrations,pH and temperatures.The results showed that most yeast strains screened from Pixian bean paste were Zygosaccharomyces rouxii while Kodamaea ohmeri,Pichia kudriavzevii,Saccharomyces cerevisiae and Hyphopichia burtonii also existed.Zygosaccharomyces rouxii BP02, the selected aroma-producing strain, was able to grow in the pH 3~8, temperature 10~37 ℃ and endured salt concentration up to 20%. The optimum growing condition for strain BP02 was 5% NaCl, pH 4~6 and 37 ℃. It was concluded that the obtained aroma-producing yeast BP02 grew well under the condition of high-salt, subacidity and moderate temperature that resembles the environment for Pixian bean paste fermentation. Therefore, strain BP02 can be inocualted into Pixian bean paste during moromi or post fermentation period to improve the flavor quality of the final product.