Comparative study of microbiological and chemical content of some fermented milk products from nasik region

A heterogeneous population of mesophilic, thermoduric, thermophilic, psychrophilic and psychrotrophic organisms constitute the microflora of milk and fermented milk products. These organisms grow and multiply in dairy products producing one or more defects due to growth and cause organoleptically detectable undesirable changes. The majority of undesirable changes includes off-flavors, change in colour, ropiness, rancid odours, proteolysis resulting in bitter flavour etc. The rate at which defect develops will depend on initial number of organisms present, rate at which organisms grow at holding temperature used and an ability of organisms to cause the organoleptically detectable change in product. Dairy products are mostly preserved by storage at refrigeration temperature by wholesale dealers and retailers but at the refrigeration temperature, milk and milk products allow the growth of psychrotrophic organisms. To study microbiota and chemical composition of these fermented milk products, five samples of curdand nine samples of shrikhand were collected in different seasons from nine different dairies of Nasik region of Maharashtra in India. Enumeration of bacteria from these samples showed the presence of mesophilic as well as psychrotrophic bacteria in each of the sample and there was a considerable variation in mesophilic and psychrotrophic bacterial content amongst the samples. Chemical examination was carried out to decide the nutritive quality of fermented milk products. The chemical examination of fermented milk products includes determination of pH, fat, total solids, SNF, proteins, sucrose and ash contents. Chemical contents of all fermented milk products were within the range mentioned by Bureau of Indian Standards.