小米发糕发酵剂中乳酸菌的筛选及其在小米发糕中的应用

Screening of Lactic Acid Bacteria from Sourdough of Fermented Millet Cakeand Its Application in the Fermented Millet Cake

以5种小米品种为研究对象,通过自然发酵法制备小米发糕发酵剂,测定菌落总数、感官评定发糕品质,获得品质差异较大的2种发酵剂,并对其中的乳酸菌进行分离、纯化,通过形态学、生理生化和测序进行鉴定。且研究了乳酸菌对小米发糕含水量、pH、TTA值、糖度和感官品质的影响。结果表明,乳酸菌的计数结果分别为6.48×10~7~8.57×10~9 cfu/g,1号(长农35)制备的小米发糕品质最好,6号(长谷4号)反之。2种发酵剂中鉴定出乳酸菌包括食窦魏斯氏菌(11株)、魏斯氏菌属(18株)和柠檬明串珠菌(4株),其中优势菌为魏斯氏菌属。乳酸菌LA6-40发酵制备的小米发糕含水量39.74%、pH 6.20、TTA值5.3、还原糖含量2.27 g/100 g,感官评分77.1分,色泽金黄、口感细腻、酸甜适中、咬劲适度、弹性良好,是较为适合小米发糕制备的乳酸菌菌株。

There were 5 kinds of millets taken as the research object in the present study. Two different kinds of fermented dough prepared by natural fermentation method were chosen by measuring colony counts and sensory evaluation of fermented millet cakes. The lactic acid bacteria(LAB) from the optimized fermented dough were isolated and purified, and preliminary screened. LAB strains were identified by morphological, physiological and biochemical and DNA sequencing. The effects on moisture content, pH, TTA value, sugar content and sensory quality of fermented millet cake were studied. The results showed that the calculation result of lactic acid bacteria were 6.48×10~7~8.57×10~9 cfu/g, respectively. The quality of millet cake prepared by No. 1(Changnong 35) was the best, and No. 6(Changgu No. 4) was the the least one. The lactic acid bacteria identified in the two starters include Weissella sinensis(11 strains), Weissella(18 strains), and Leuconostoc citrate(4 strains), wherein the dominant bacteria are Weissella. Plus, the moisture content of rice cake prepared by lactic acid bacteria LA6-40 was 39.74%, with pH being 6.20, TTA value being 5.3, reducing sugar content of 2.27 g/100 g, sensory score of 77.1 points. It features golden color, fine taste, moderate sweet and sour taste, moderate bite and good elasticity. In addition, it is a strain of lactic acid bacteria which is more suitable for the preparation of millet cakes.