青稞酒曲中糖化菌的筛选鉴定及降低青稞淀粉工艺优化  

Screening and identification of saccharifying strains in the highland barley kojiand process optimization for degrading barley starch

作　　者：王晓燕 王蓉福 张昊宇 院珍珍 曹效海[1,3] 王树林 杜艳[2] WANG Xiaoyan;WANG Rongfu;ZHANG Haoyu;YUAN Zhenzhen;CAO Xiaohai;WANG Shulin;Du Yan(College of Agriculture and Animal Husbandry,Qinghai University,Xining 810016,China;Qinghai Province Highland Barley Resources Comprehensive Utilization Engineering Technology Research Center,Xining 810016,China;United Laboratory of Food Research and Testing of Qinghai-Gansu Province,Xining 810016,China)

机构地区：[1]青海大学农牧学院,青海西宁810016 [2]青海省青稞资源综合利用工程技术研究中心,青海西宁810016 [3]青海-甘肃食品研发与检测联合实验室,青海西宁810016

出　　处：《食品与发酵工业》2020年第5期160-165,共6页Food and Fermentation Industries

基　　金：青海省科技厅自然科学基金青年项目(生物法降低青稞快消化淀粉及低GI食品的研发)。

摘　　要：为降低青稞淀粉含量,对青稞酒曲中糖化菌进行筛选及液体发酵工艺优化,并采用糖化菌发酵及固液分离技术生产低糖青稞粉。以糖化力为指标,筛选出糖化力为359.62μg/(g·h)的优势糖化菌株,经形态学及分子生物学鉴定确定为米曲霉,其最适生长温度为40℃,最适生长pH为4.0,具有一定的耐钠离子能力,35℃下测定其生长曲线,发现0~3 d为米曲霉的生长迟滞期,3~5 d为对数期,6~7 d为稳定期。利用此菌株降解青稞中淀粉,在单因素试验基础上进行Box-Behnken中心组合试验,确定最佳的发酵条件为发酵时间2.8 d、发酵温度37.6℃、菌种接种量6.6%。结果表明,微生物降解青稞中淀粉化合物是一种高效的方法,研究结果对于低糖青稞产品的开发利用具有重要意义。In order to reduce the content of starch in highland barley,the saccharification fungus was screened from barley koji and the liquid fermentation process was optimized.Low-sugar barley powder was produced by saccharification fungus fermentation and solid-liquid separation technologies.The dominant saccharification strain with saccharification efficiency of 359.62μg/(g·h)was screened using saccharification efficiency as the index.It was further identified as Aspergillus oryzae by morphological and molecular biological identification.The optimum growth temperature and pH of this strain were 40℃and 4.0,respectively.The saccharide strain had a certain ability to resist sodium ions.The growth curve of Aspergillus oryzae at 35℃showed that 0-3 days was the growth retardation period,3-5 days was the logarithmic period,and 6-7 days was the stable period.Starch in highland barley was degraded by fermentation with this screened strain.The Box-Behnken center combination design was carried out based on the single factor tests.The optimal fermentation time was 2.8 days under 37.6℃,and the inoculum size was 6.6%.The results showed that microbial degradation of starch in highland barley is an efficient method and the results have important value and significance for the development and utilization of low sugar highland barley products.

关 键 词：青稞 发酵 糖化力 糖化菌 响应 

分 类 号：TS261.11[轻工技术与工程—发酵工程]