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

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。

Screening of Lactic Acid Bacteria from Sourdough of Fermented Millet Cake and its Application in the Fermented Millet Cake

The object of this dissertation was 5 kinds of millets. 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 purification, and preliminary screened. The strains of LAB 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. In all the samples, the number of LAB ranged from 6.48×107 to 8.57×109cfu/g. The fermented millet cake made by no.1 (Changnong 35) and no.6 (Changgu 4) were the best and worst quality, respectively. Thirty-three LAB species, including Weissella cibaria (11), Weissella (18) and Leuconostoc citreum (4), were identified. Among the thirty-three identified LAB, the dominant species was weisiella. The characters of millet cake fermented by the LA6-40 was moisture content 39.74%, pH6.20, TTA value 5.3, reducing sugar content 2.27g/100g, and its sensory score 77.1. The LA6-40 is suitable for millet cake preparation and it receives warm welcomes with its golden color, delicate taste, moderate sour and sweet taste, good elasticity.