Assessment of beverages made from milk, soya milk and whey using Iranian kefir starter culture

Kefir starter culture was used for the production of beverages, and some chemical and microbiological parameter changes were determined during 24 h of fermentation and then after 2, 7, 14, 21 and 28 days of storage at 4 °C. Three different substrates (milk, whey and soya milk) were used as fermentation media for the kefir starter culture. After the fermentation, the carbohydrate content and pH decreased, but the dry matter and fat content of the beverages were not significantly different from their substrates. During storage, lactic acid bacteria in the beverages decreased, while yeasts increased and carbohydrate, ethanol and pH changed significantly in the three beverages.