嗜温乳酸菌与白地霉混合发酵酸乳的研究

Study on Yogurt by Mixed Fermentation of Lactococcus Lactis and Geotrichum Candidum

与高温发酵酸乳相比,嗜温乳酸菌与霉菌联合发酵酸乳有更丰富的风味物质,且嗜温发酵酸乳粘稠、细腻,香气浓郁、纯正,酸甜适口.采用编号为3-7和3-9的嗜温乳酸菌与1株产香白地霉联合发酵生产酸乳,通过混料试验设计,得到酸乳发酵剂的优化菌种体积配比(乳酸菌3-7∶乳酸菌3-9∶白地霉)为50∶5∶45时,其风味、质地和气味较佳.该酸乳具有很高的有效营养成分,其胞外多糖质量浓度高达643.2 mg/L,具有较高的生理功能.其中白地霉不仅能与乳酸菌互利共生产生真菌胞外多糖,而且其产生的香气成分还能有效地提高呈香型物质的种类和含量,改善酸乳的风味质量.

Compared with the high temperature fermented yogurt, mixed fermented yogurt has more vola- tile compounds and more favorable taste and flavor. In this study, the yogurt was produced by applying two Lactococcus Lactis strains and one Geotrichum candidum strain together. The optimal combination of strains was 50： 5：45 （v/v） , determined by mixture design. The yogurt has high concentration of exopo- lysaccharides （up to 643.2 mg/L） , which means its high functionality. Besides, the addition of Geotri- chum candidum not only increased the EPS concentration in the yogurt, but also increased the types of a- roma components and improved the flavor of the yogurt.