乳酸菌发酵接骨木果汁品质及挥发性风味物质的变化

Changes of Quality and Volatile Flavor Compounds of Elderberry Juice Fermented by Lactic Acid Bacteria

以植物乳杆菌L1和发酵乳杆菌L2为发酵菌株,对接骨木果汁进行发酵,测定果汁发酵过程中pH值、总酸、色差值、花色苷含量、总酚和总黄酮含量、超氧阴离子清除率、总还原力的变化,并测定发酵前、后挥发性风味物质的变化。结果表明,发酵期间,接骨木果汁pH值显著降低,总酸大量增加,L^(*)值和a^(*)值先上升后下降,b^(*)值较为稳定,花色苷含量下降,总酚和总黄酮含量均提高,超氧阴离子清除率和总还原力较发酵前分别提高了82.07%和55.27%。从未接种以及接种发酵前、后的各样品中共检测出挥发性风味物质99种,通过主成分分析法得出3个样品特征风味差异显著。结论:接骨木果汁经乳酸菌发酵可提高营养价值、抗氧化能力和风味品质。

In this study,Lactobacillus plantarum L1 and Lactobacillus fermentum L2 were selected as inoculated strains to ferment elderberry powder to make fermented juice.The changes of pH value,total acid,color difference value,anthocyanin content,total phenol and total flavone content,superoxide anion scavenging activity,total reduction capacity,and volatile flavor compounds before and after fermentation were determined.The results showed that during the fermentation period,the pH value of elderberry juice decreased but the total acid increased significantly.The L^(*)value and a^(*)value increased first and then decreased,and the b^(*)value was relatively stable.The anthocyanin content decreased,but the total phenol and total flavonoids content increased.The superoxide anion scavenging rate and total reduction capacity increased by 82.07%and 55.27%,respectively.A total of 99 volatile flavor compounds were detected among the uninoculated samples and fermented juice samples before and after fermentation.The results showed that there were significant differences in flavor characteristics among three samples by principal component analysis.In conclusion,the nutritional value,antioxidant capacity and flavor quality of elderberry juice can be improved by lactic acid bacteria fermentation.