Process optimization of fortified sweetened milk kefir

Abstract

Kefir is an acidic-alcoholic fermented milk product. Consumption of kefir regularly is helpful in relieving intestinal disorders, reduce flatulence and create healthier digestive system. An attempt was made to optimise the process to produce fortified sweetened milk kefir.  Kefir was prepared using kefir grains with sugar (6, 8 and 10%), fibres (inulin, oat and soya, each 3%) and stabilizer (0.1% pectin).  Addition of 6% sugar showed significantly (p˂0.05) higher body and texture scores with no significant (p>0.05) difference in flavour, colour and appearance in  kefir made with 8 and 10% sugar. Similarly, Overall acceptability was highest in kefir made with 6% sugar. Firmness was highest in kefir made with 6% sugar, followed by 8 and then 10% sugar. Among three fibers, addition of 3% inulin showed significantly (p˂0.05) better sensory attributes than kefir added with soya and oat fiber. Acidity of inulin added kefir was lowest among soya and oat fiber added kefirs which was optimum. Kefir prepared with soya fiber showed significantly (p<0.05) higher acidity than other two samples. No significant (p>0.05) difference was observed in pH among all kefir samples. Firmness and consistency increased significantly (p<0.05) with the addition of inulin. An acceptable quality fortified sweetened milk kefir can be prepared with 0.1% pectin, 6% sugar and 3% inulin as dietary fibre for improved health benefit.