发酵绿茶饮料工艺优化、抗氧化活性及贮藏品质研究

Process Optimization, Antioxidant Activity and Storage Quality of Fermented Green Tea Beverage

以绿茶浸提液为原料,利用前期自主分离筛选出的植物乳杆菌ST对其进行发酵,以感官评分为主要评价指标,结合抗氧化活性,采用单因素试验和响应面法对发酵茶饮料工艺进行优化。与未发酵绿茶浸提液对比,分析发酵绿茶饮料抗氧化性,并对发酵绿茶饮料的贮藏品质进行研究。结果表明,植物乳杆菌ST发酵绿茶饮料最佳工艺为接种量7 lg(CFU/mL)、加糖量6.6%、发酵温度38.7℃、发酵时间17 h,该条件下感官评分为76.31。与未发酵绿茶相比,发酵绿茶饮料DPPH·和ABTS^(+)·的清除率均显著增加(P<0.05)。饮料在4℃下贮藏21 d,贮藏期内饮料活菌数稳定维持在6 lg(CFU/mL)以上,茶多酚和咖啡因含量以及DPPH·和ABTS^(+)·的清除率较高,风味及口感稳定。

Aqueous extract of green tea was fermented with Lactobacillus plantarum ST isolated in the previous study.The fermentation conditions were optimized via single factor experiments and response surface methodology.The sensory score combined with antioxidant activity was used as the evaluation index.The antioxidant properties of fermented tea beverage were analyzed and compared with those of unfermented tea extract.In addition,the quality of fermented tea beverage during storage was evaluated.The optimal fermentation conditions were determined as L.plantarum ST inoculation amount of 7 lg(CFU/mL),sucrose addition amount of 6.6%,and fermentation at 38.7℃for 17 h.The beverage fermented under such conditions had the sensory score of 76.31.The fermented green tea beverage outperformed the unfermented green tea in terms of DPPH·and ABTS^(+)·scavenging activities(P<0.05).After storage at 4℃for 21 days,the fermented green tea beverage had the viable count of lactic acid bacteria over 6 lg(CFU/mL),high concentrations of tea polyphenols and caffeine,strong of DPPH·and ABTS^(+)·scavenging activities,and good flavor and taste.