‘红茶菌’发酵饮料生产工艺及其功能特性研究

目的优化纯菌混合发酵制备‘红茶菌’发酵饮料的生产工艺,并对优化后的‘红茶菌’发酵饮料的功能特性进行考查。方法以糖茶水为基底,通过单因素试验考察接种量、葡萄糖添加量以及茶叶添加量对‘红茶菌’发酵饮料总糖利用率和感官评分的影响,并采用响应面分析法得出最佳工艺。采用优化工艺条件对‘红茶菌’发酵至第6 d,采用1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl radical,DPPH)自由基清除能力、2,2’-联氮-双-3-乙基-苯并噻唑啉-6-磺酸[2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid),ABTS]阳离子自由基清除能力评价抗氧化能力,96孔板法进行抑菌能力分析,采用DNS法进行抑制α-淀粉酶能力分析。结果最佳工艺为接种量为8.0%、葡萄糖添加量14.5%、茶叶添加量1.2%。优化后‘红茶菌’发酵液pH下降至3.2左右,总酸浓度为1.632 g/L,总酚最高可至332.7 mg/mL。优化后发酵液DPPH自由基以及ABTS+自由基的清除率分别达到了81.32%和82.92%,金黄色葡萄糖菌、大肠杆菌和单增李斯特菌的最小抑菌浓度分别为128、16和16 mg/mL,对α-淀粉酶的抑制作用达87.53%。结论优化工艺可明显提高‘红茶菌’发酵饮料的抗氧化能力,对金黄色葡萄糖球菌、大肠杆菌、单增李斯特菌具有明显的抑制作用,对于α淀粉酶的抑制作用也有较大提升。

Antimicrobial Activity in Kombucha Fermentation Broth

[Objective] The aim was to study if the fermentation broth of Kombucha has protein with antimicrobial activity. [Method] The effects of different cultivation time on cell concentration, pH, total protein concentration and inhibition zone were studied. The fermentation broth of Kombucha on the sixth day was adjusted to different pH. Fermentation broth treated with protease was put into the plates of Escherichia co/i, Bacillus cereue and Staphylococcus aureus as control, as well as ampenicilin. The zone of broth inhibition was measured. [ Result] The concentration of general protein was of positive relevance to the antimicrobial activity of Kombucha fermentation broth. The zone of inhibition decreased with rising pH and was the lowest when pH was 7. Later, as pH increasing, it enlarged. The inhibition effect of processed protease reduced remarkably. [ Conclusion] The fermentation broth of Kombucha revealed antimicrobial proteins.