Preparation of A Novel Kefir Flavor Compound Fermentation Starter
Article
Figures
Metrics
Preview PDF
Reference
Related
Cited by
Materials
Abstract:
To develop a compound starter with excellent flavor and stable physical and chemical properties, 51 strains of lactic acid bacteria (LAB) and 22 strains of yeasts were isolated from ten types of kefir grains collected from Xinjiang, China. Among the LAB strains, three exhibited outstanding incense production and proteolytic ability. The textural characteristics of single-bacteria-fermented milk were the most stable. The acetaldehyde, diacetyl, and amino nitrogen concentrations for Lactobacillus kefir MLK5 were 15.82, 3.99, and 597.09 mg/L, respectively, and those for Lactobacillus casei SLC1 and Leuconostoc membranae NLM2 were 20.02, 4.69, and 684.92 mg/L and 18.01, 4.44, and 600.58 mg/L, respectively. The yeast, Kluyveromyces marxianus FY1, exhibited a suitable ethanol yield, good genetic stability, and the highest lactose utilization rate (56.56%). The optimal ratio of LAB to yeast in the starter was 5:1, and the optimal proportion of the 3 LAB strains was Leuconostoc mesenteroides: L. kefir: L. casei = 1:2:1. The curd time of compound fermented milk, acidity, water holding capacity, ethanol content, viable count of LAB, viable count of yeasts, and sensory score were 6.0 h, 84.65 °T, 62.31%, 0.53%, 3.89×109 CFU/mL, 4.61×106 CFU/mL, and 89.21. These indexes are similar to those of kefir grain fermented milk. The volatile flavor compounds in compound fermented milk were found to be harmonious and more acceptable to consumers. These results will help stabilize and simplify the industrial production of kefir and provide a reference for the development of different flavored yogurt products.
