双霉菌混合发酵腐乳前发酵条件优化及酶活研究
Study on the optimization and enzyme activity of co- fermentation sufu pr-fermentation with double moulds
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摘要: 八公山腐乳前发酵工艺对其总体风味具有重要影响,在总状毛霉和米根霉单独发酵腐乳的基础上,探索总状毛霉(Mucorracemosus)和米根霉(Rhizopusoryzae)混合发酵腐乳的发酵工艺。在单因素的基础上,以蛋白酶活力和糖化酶活力为评价指标,选取发酵时间、发酵温度和混合比例为影响因子,采用响应面法优化总状毛霉和米根霉混合发酵腐乳的前发酵条件,比较最优条件下混合发酵和总状毛霉与米根霉单独发酵的前发酵情况。研究结果表明总状毛霉和米根霉混合发酵的前发酵条件为:发酵时间56 h、发酵温度28℃、混合比例(总状毛霉和米根霉)1∶1,此时分泌产蛋白酶活力50.51 U/m L,糖化酶活力为15.15 U/m L。通过对比双菌和单菌发酵腐乳前发酵情况可知:总状毛霉和米根霉混合发酵较总状毛霉更能耐高温,且在菌丝的生长和酶系的分泌积累较单独发酵都更有优势,为后期发酵的一系列生化反应奠定了良好的基础,有利于改善腐乳的发酵周期,提高腐乳的品质。Abstract: The pre- fermentation of bagongshan sufu had an important influence in the overall nutrition flavor.Based on the single fermentation of Mucor racemosus and Rhizopus oryzae,the exploration for its fermentation process surrounding both common strain( Mucor racemosus and Rhizopus oryzae) was needed. According to the basic fermentation conditions,the fermentation time,fermentation temperature and ratio of strain were investigated through single factor experiment. On the basis of single factor experiment,the activities of protease and glucoamylase were as response value and the prophase fermentation of co- fermentation of sufu by Mucor racemosus and Rhizopus oryzae was identifed using response surface methodology. The pr- fermentation was considered by comparing of co- fermentation and separate fermentation. The conditions of the multi- fermentation were found that the fermenting time was 56 h,fermenting temperature was 28 ℃,ratio of strain was 1 ∶ 1,and the activity of protease was 50.51 U / m L,the activity of glucoamylase was 15.15 U / m L.Through the comparison of both strains,the result indicated that the enzyme system and sensory attributes of sufu pehtez in co- fermentation was better than separate fermentation,which laid a theoretical foundation for later fermentation,improved the fermented sufu fermentation period and improved the quality of sufu.