Dahi is an important fermented milk product. Liquid culture is normally used in the preparation of Dahi where microbial contamination with sequential propagation of liquid culture are the noted limitations. Dried and frozen cultures show lower viability and in order to overcome these problems, Direct Vat Set cultures are slowly introduced in the commercial sector. The present study was carried out to develop Direct Vat Set Dahi cultures through solid sate fermentation technique. Dahi samples of 5 each were collected from houses and local markets of Bengaluru. That showed total lactic bacterial viable count ranging from 5.36 to 7.04. Among 72 lactic isolates obtained. lactobacilli predominated (38) followed by leuconostoc (18); lactococci (9) and streptococci (7). The lactic cultures that set the milk with higher direct microscopic counts in sterile skim milk were Leuconostoc sp. Leu6: L. lactis ssp. lactis Lc1: L. fermentum Lb8: S. thermophilus St3 especially at the ratio of 0.15 %: 0.3 %: 0.5%: 1 %. The growth of mixed dahi culture on sterile black gram dhal with 1% skim milk powder, 10% tomato juice and 70% moisture as solid substrate medium showed 9.42 log10cfu/g at 24 hrs of incubation. SSF Dahi culture or DVS Dahi culture at ambient and refrigeration temperature revealed viable count reduction in total lactic count by 4.5 log and 3.5 log by the end of 70 days and 60 days of storage respectively. Dahi prepared from refrigerated stored DVS culture scored better than Dahi prepared out of ambient temperature stored DVS culture.

Lactic acid bacteria, Dahi, DVS cultures, Liquid cultures and solid state fermentation

Solid state fermented (SSF) Dahi culture or DVS Dahi culture was prepared by inoculating liquid culture of 2% level on to black gram dhal medium as solid substrate and incubated at 30°C for 24 hrs as it yielded higher DMC, dried at 20°C in BOD incubator for 18 hrs. The total lactic count of dried DVS culture was 9.75 log10/g.

Deepa B.G., Manjunatha H., Akshaykumar, Basavabharati and Madhusudan N.M. (2023). Preparation of Direct Vat Set Cultures from Domestic Lactic Cultures. Biological Forum – An International Journal, 15(12): 159-162.