酸面团酵母菌Sy22的分离与发酵性能评价

为了获得性能优良的面团发酵菌株,本试验从来自内蒙古的发酵酸面团中分离获得5株酵母菌株,分别对其发酵性能进行测定,最终选取性能优良菌株Sy22进一步研究。基于形态学、生理生化试验以及26SrDNAD1/D2区序列分析综合测试结果,菌株Sy22被鉴定为酿酒酵母(Saccharomyces cerevisiae)。在30℃下发酵12h,分别对单独添加该菌株面团的发酵性能以及该菌株与类食品乳杆菌412联合发酵面团的发酵性能、活菌数进行研究,结果显示:单一酵母菌株发酵后,面团pH由6.07降至5.36,滴定酸度由3.6°T增加到5.02°T,发酵力为0～1.32%;联合菌株发酵后,酸面团pH由5.58下降至3.85,滴定酸度由5.24°T增加到14.02°T,发酵力为0～1.79%,酸面团中的酵母菌活菌数为8.2×108 CFU/g,乳杆菌412活菌数为9.6×109 CFU/g。由此得出,菌株Sy22可单独作为面团发酵菌株使用,能很好的参与面团的发酵;与类食品乳杆菌412联合后发酵能力好,并表现出良好共生性。

Fermentation performance of yeast Sy22 isolated from sourdough

In order to get good dough fermentation strains,five yeast strains isolated from fermented sourdough from Inner Mongolia of China were screened according to their growing performance.Among the 5 strains,strain Sy22 showed the best growth during dough fermentation process.Strain Sy22 was identified as Saccharomyces cerevisiae according to its morphological,physiological and biochemical properties as well as 26SrDNA of the D1/D2 sequence data.Fermented at 30°C for 12 h,respectively,the dough fermentation performance of strain Sy22 as well as the combination of strain Sy22 and Lactobacillus paralimentarius 412 dough fermentation performance,the number of viable cells were studied.The results showed that,after single yeast strain fermentation,dough pH decreased from 6.07 to 5.36,its titratable acidity was increased from 3.6°T to 5.02°T and a fermenting power from 0to 1.32%(calculated as release volume of CO 2).Combined strains fermentation sourdough had a decreased pH from 5.58to 3.85,and its titratable acidity was increased from 5.24°T to 14.02°T,together with a fermenting power from 0to 1.79%,The number of viable cells was 8.2×10 8 CFU / g for strain Sy22,and 9.6×10 9 CFU / g for L.paralimentarius 412.The results also showed that the yeast strain Sy22should be very promising for the use as sourdough starter in steamedbread making,and could be involved in the fermentation of the sourdough.Its combination with L.paralimentarius 412was found to have good fermentation capacity,and showing a good symbiotic between them.