Microbiological, chemical and ultrastructural characteristics of Mishti Doi (sweetened dahi)

Samples of Mishti Doi (Sweetened Dahl) sold in and around Calcutta market w ere analysed for microbiological. chemical and ultrastructural characterist ics. The wide variations in different parameters can be attributed to manuf acturing conditions and the type of starter cultures used. This survey was particularly exploited for the standardization of a good quality Mishti Dol . Two promising starter combinations were developed comprising (i) Streptoc occus salivarius ssp. thermophilus 74 (Hansen) + Lactobacillus acidophilus 15 (Russian strain BA + KE) + Lactobacillus delbrueckii ssp. bulgaricus 4 ( NDRI), (ii) Lactobacillus acidophilus 13 (NDRI 111) + Lactococcus lactis ss p. lactis 89 (NDRI S-59) + Saccharomyces cerevisiae 42 (NDRI) in 1:1:1 rati o. Ultrastructure study of both market and experimental samples presented d ifferent casein-stabilizer matrices showing defined distribution of lactic acid bacteria and yeast cells in the experimental samples.