益生菌发酵对苹果汁主要营养成分及挥发性物质的影响

以红富士苹果汁为原料，研究益生菌混菌发酵对苹果汁挥发性物质及主要营养成分的影响。结果表明，苹果汁经混合益生菌发酵后，琥珀酸、苹果酸含量明显下降，而乳酸、柠檬酸、酒石酸、奎宁酸、莽草酸与丙酮酸的含量均明显上升；总酚含量呈先上升后下降趋势；儿茶素、表儿茶素、槲皮素、根皮苷和芦丁含量分别上升了5.57%、5.65%、5.83%、19.2%和4.52%，绿原酸含量下降了14.9%。发酵后的苹果汁共检出37种挥发性物质，与发酵前相比，增加了10种。其中，醇类增加5种、含量增加106.9%，酯类增加8种、含量增加84.5%；酮类种类不变，含量增加171.7%；醛类减少3种、含量降低了80.9%。

Effect of probiotic fermentation on main nutrients and volatile substances in apple juice

The effect of mixed probiotic fermentation on volatile substances and main nutrients in apple juice was investigated using Fuji apple juice as raw material. The results showed that after fermentation with mixed probiotics, the contents of succinic acid and malic acid decreased significantly, while the contents of lactic acid, citric acid, tartaric acid, quinic acid, shikimic acid and pyruvic acid increased significantly. The contents of total phenolics increased first and then decreased. The contents of catechin, epicatechin, quercetin, phloridzin and rutin increased by 5.57%, 5.56%, 5.83%, 19.2% and 4.52%, respectively. The content of chlorogenic acid decreased by 14.9%. A total of 37 volatile substances were detected in apple juice after fermentation. Compared with the initial apple juice, 10 new volatile substances were produced. Among them, alcohols increased by 5 kinds, and the content increased by 106.9%; esters increased by 8 kinds, and the content increased by 84.5%; the ketone types remained unchanged, and the content increased by 171.7%; the aldehydes decreased by 3 kinds, and the content decreased by 80.9%.