乳酸菌、酵母菌的筛选鉴定及其在米发糕中的应用

为得到适合米发糕发酵的发酵剂,对传统发酵米浆中的乳酸菌和酵母菌进行分离,通过对其菌落、菌株形态特征及生长性能的测定,筛选得到1株乳酸菌和2株酵母菌,分别经16S rDNA和26S rDNA鉴定,确定为植物乳杆菌(Lactobacillus plantarum)、矮小假丝酵母菌(Candida humilis)和酿酒酵母菌(Saccharomyces cerevisiae)。将3株优良发酵菌株复配应用于米发糕中,通过对其发酵所得产品的感官品质及质构特性进行分析,确定出最佳复配菌比。结果表明:当植物乳杆菌(Lactobacillus plantarum)、酿酒酵母(Saccharomyces cerevisiae)和矮小假丝酵母(Candida humilis)的复配体积比为136时,所得米发糕的感官品质和质构特性最好,且由GC-MS检测到29种挥发性风味物质,其中与市售米发糕和双菌复合发酵得到的米发糕共同检出5种风味物质,分别是苯乙醛、苯甲醛、苯乙醇、十四烷和棕榈酸乙酯,其特有的风味物质有12种,其中9种为酯类物质。该种复合发酵剂发酵得到的米发糕具有较好的品质,有望应用于米发糕的发酵生产。

Screening and identification of lactic acid bacteria and yeasts and its application in fermented rice cake

In order to obtain starter cultures with good performance for fermented rice cake, lactic acid bacteria strains and yeast strains were isolated from traditional fermented rice slurry.Through the investigation of colonies, morphological characteristics and growth properties one strain of lactic acid bacteria and two strains of yeasts were screened.According to the 16S rDNA and 26S rDNA sequence analysis, they were identifided as Lactobacillus plantarum , Candida humilis and Saccharomyces cerevisiae .Remixing three superior fermentation strains in fermented rice cake, the optimum bacteria ratio was determined by analyzing the sensory quality and texture characteristics of the fermented products.The results showed that when the proportion of actobacillus plantarum , Saccharomyces cerevisiae and Candida humili s was 1 3 6, the sensory quality and texture property of fermented rice cake were the best and 29 kinds of volatile flavor substances were detected by GC-MS.Five kinds of flavor substances were detected together with the commercial rice cake and the double bacteria compound starter, such as phenylacetaldehyde, benzaldehyde, phenylethyl alcohol, tetradecane and ethyl palmitate.And 12 kinds of unique flavor substances were detected.Among them, nine of which were esters.The rice cake produced by the fermentation of the compound starter had better quality, which was expected to be applied to the fermentation production of rice cake.