以鲜榨并经灭菌的蓝莓黑莓混合果汁为原料，接入3种不同的乳酸菌（植物乳杆菌、乳酸乳杆菌、肠膜明串珠杆菌）进行发酵，研究发酵过程中乳酸菌活菌数、pH、总酸、总糖、还原糖、总酚、体外抗氧化和抑菌活性变化规律。结果表明，乳酸菌在混合果汁中生长良好，24 h时活菌数最高，为1.23×108 cfu/mL；发酵过程中，pH值不断降低，由最初的5.50降低到3.75，总酸含量呈不断上升趋势，从初始含量0.15 g/100 mL上升到2.15 g/100 mL；还原糖呈先短暂上升然后下降趋势，发酵至6 h为最高值2.63 g/L，总糖被微生物利用消耗, 质量浓度不断下降，42 h后趋于0 g/L；总酚含量从2.32 mg/mL升高到3.26 mg/mL，发酵前后增加了40.52%；DPPH·、羟基自由基和超氧阴离子自由基清除能力比未发酵前分别提升了18.17%、30.67%和34.55%。发酵混合汁对大肠杆菌、金黄色葡萄球菌、酿酒酵母和黑曲霉等几种微生物的抑菌作用显著，抑菌效果随发酵时间而逐渐提高。因此，利用复合乳酸菌发酵来提升蓝莓黑莓混合汁品质和开发功能性产品具有重要意义。

Freshly squeezed and sterilized blueberry and blackberry juice mixture was used as the raw material for the fermentation with three different lactic acid bacteria (Lactobacillus plantarum, Lactobacillus lactis and Leuconostoc mesenteroides). The changes in the number of live lactic acid bacterium colonies, pH value, total acid, total sugar, reducing sugar and total phenolic content, in vitro antioxidant activity and bacteriostatic effect during fermentation were studied. The results showed that the lactic acid bacteria grew well in the juice mixture, with the highest colony number of viable bacteria (1.23×108 cfu/mL) occurring at the 24th h. During the fermentation, the pH value decreased constantly (from initial 5.50 to 3.75) while the total acid content increased continuously (from 0.15 to 2.15 g/100 mL). The reducing sugar content increased briefly and then decreased with the peak value (2.63 g/L) at 6 h, while the concentration of total sugar decreased steadily, due to the consumption by microorganisms, till almost 0 g/L after 42 h of fermentation. The content of phenolic compounds changed from 2.32 to 3.26 mg/mL (increase by 40.52% after fermentation). The DPPH·, hydroxyl and superoxide anion free radical scavenging rates increased by 18.17%, 30.67% and 34.55%, respectively, after fermentation. The fermented juice mixture significantly inhibited Escherichia coli, Aspergillus niger, Saccharomyces cerevisiae and Staphylococcus aureus, and the inhibitory activities increased gradually with fermentation time. Therefore, the use of fermentation by composite lactic acid bacteria is of high significance in terms of improving the quality of the blueberry and blackberry juice mixture and developing functional food products.

江苏省农业科技自主创新资金（CX(18）2017)；江苏省自然科学基金青年基金项目(BK20150541)；江苏省农业科学院农产品加工研究所科研基金项目（JG(2017)06)