植物乳杆菌对辣白菜发酵过程中风味物质及菌群结构的影响

Effects of Lactobacillus plantarum on flavor and microflora structure of spicy cabbage during fermentation

对比接种发酵和自然发酵辣白菜样品,研究植物乳杆菌的接种对辣白菜风味和微生物结构的影响。检测2种不同处理样品中乳酸菌数量、可滴定酸、还原糖和氨基酸含量以及挥发性风味物质在发酵过程中的变化,通过高通量测序分析菌群结构。接种发酵样品中乳酸菌数量提前2d达到最大值lg7.34CFU/g,且在发酵第7天时乳杆菌属含量占乳酸菌总数的98.16%,但物种丰度明显降低;接种发酵组中样品可滴定酸含量在第5天时积累量达到0.52%;此外,接种发酵组样品中还原糖含量和氨基酸含量均高于自然发酵组;两样品中共检测出84种挥发性风味成分,发酵剂的接种导致样品中二甲基硫化物含量明显增加。植物乳杆菌作为单菌种发酵剂,能加快发酵进程,缩短发酵时间并达到改变菌群结构和改善风味的目的,为辣白菜工业化产品品质控制奠定基础。

The effects of Lactobacillus plantarum(L.plantarum)on the flavor and microflora structure of spicy cabbage were studied by comparing inoculated and naturally fermented samples.Changes in the number of lactic acid bacteria(LAB),the contents of titratable acids,reducing sugar,amino acids and volatile flavor components during fermentation were measured.The number of lactic acid bacteria in inoculated samples reached the maximum of lg 7.34 CFU/g two days ahead,and the content of Lactobacillus accounted for 98.16%of total LAB on day 7,but the abundance of species decreased obviously.Moreover,the content of titratable acids reached 0.52%on day 5,and the contents of reducing sugar and amino acids were higher than that in naturally fermented ones.In total,84 volatile flavor components were detected in both samples and the content of dimethyl sulfide significantly increased in inoculated samples.In conclusion,L.plantarum as a starter culture can accelerate the fermentation process,shorten the fermentation time,change the microflora structure and improve the flavor of products,which may lay a foundation for quality control of industrial production of spicy cabbage.