高产植酸酶乳酸菌及其黑豆酸面团发酵低植酸营养面包研究

从自然发酵的黑豆中筛选出一株具有高植酸酶活性的乳酸菌L-19并将其作为发酵剂制作黑豆酸面团。通过响应面分析法对黑豆酸面团的发酵工艺进行优化,探究最佳发酵条件下目标菌株的生长及产酸特性,并分析体系中多肽的分子量分布及抗营养因子含量变化,同时以感官品评的方式对黑豆酸面团面包的烘焙特性进行评价。结果表明:乳酸菌L-19经鉴定为乳酸片球菌(Pediococcus acidilactici),其胞外酶与胞内酶活性分别为1.36,0.30 U/mL。通过响应面设计确定的最优发酵条件为面团得率(DY)300、发酵温度37℃、接种量8%,黑豆基质中,目标菌株生长良好、酸化能力适中。黑豆酸面团经发酵后,体系中的多种抗营养因子得到有效降解,其中植酸降解率高达62.70%。此外,黑豆蛋白水解后释放出多种肽,其中小分子肽占比达51.47%。与对照组相比,L-19黑豆酸面团面包表现出更高的整体可接受度。因此,乳酸片球菌L-19能够有效改善黑豆酸面团面包的营养及感官品质,具有较佳的应用潜力。

Studies on screening of high-yield phytase-producing lactic acid bacteria and its low-phytate nutritional breads through black bean sourdough fermentation

In this study,a strain of lactic acid bacteria(LAB)L-19 with high phytase activity selected from spontaneous fermentation black bean substrate was used as starter to prepare black bean sourdough.The fermentation process of black bean sourdough was optimized by response surface design.The growth of LAB and acidity of the sourdough were investigated in the work,and the molecular weight distribution of peptides and the degradation ratio of anti-nutritional factors(ANF)were analyzed during sourdough fermentation.Meanwhile,the baking characteristics of black bean sourdough bread were evaluated.The results showed that LAB L-19 with phytase-producing capacity was identified as Pediococcus acidilactici,and its extracellular and intracellular phytase activity were 1.36 U/mL and 0.30 U/mL,respectively.The optimal fermentation conditions were determined by response surface analysis as followed:DY value 300,fermentation temperature 37℃,inoculation quantity 8%.The LAB L-19 grew well in black bean sourdough and showed moderate acidizing ability.Various anti-nutritional factors were effectively degraded in black bean sourdough,the degradation ratio of phytic acid was as high as 62.70%.In addition,a variety of peptide were released due to proteolysis of black bean,of which small molecule peptides accounted for 51.47%.Compared with the control,the overall acceptability of L-19 black bean sourdough bread was also higher.Therefore,the nutritional and sensory quality of product were improved by the LAB L-19 fermentation,and showed a potential application in black bean sourdough bread.