Abstract: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.
