Developing Starter Culture from Lactic Acid Bacteria Isolated from Cow Milk for the Production of Nigerian “Nunu”

Abstract

Starter cultures are mostly organisms deliberately introduced into food as a single culture or mixture of cultures to bring about fermentation and production of desired characteristics in food through metabolic and enzymatic activities. Organisms in this category have attained the generally regarded as safe (GRAS) status, are majorly lactic acid bacteria with food acidification and production of natural preservatives potential. This research was aimed at developing a starter culture for the production of local dairy drink “Nunu” Cow milk was obtained from “Gaa Mobolohunduro”, Tanke, Ilorin, Kwara State, Nigeria. Potential lactose fermenters were isolated on MRS agar in pour plate technique. The isolates were characterized and identified using standard procedures. Lactic Acid Bacteria isolated were inoculated as a starter culture for milk fermentation and the products were subjected to pH, titratable acid and organoleptic assessments following standard procedures. Two of the isolated lactic acid bacteria with the best fermentation products were identified through molecular technique. A total of six isolates were obtained and identified as Lactococcus sp., Leuconostoc sp., Pediococcus sp. and Lactobacillus spp. The pH ranges from 5.46±0.01 to 6.03±0.01while the titratable acidity ranged from 0.244±0.004 to 0.526±0.006. The moisture content ranged from 90.50±0.30 to 91.75±0.35. The fermentation product from the isolated Lactobacillus sp. scored 80 % during the organoleptic assessment. Molecular evidence confirmed the two isolates as Lactic Acid Bacteria. In conclusion, isolated species could be used as potential organisms for milk fermentation.