How kefir fermentation can affect product composition?

• Kefirs were prepared with inoculation of natural kefir grains into Saanen, hair goat and cow’s milk.
• Feeding conditions, breeds and fermentation had significant influences on vitamin-mineral contents for milk and kefir.
• Goat kefir with superior micro nutrients would be a functional beverage in daily nutrition.

The aim of this study was to investigate the effects of kefir fermentation on the chemical properties, as well as the vitamin and mineral compositions of hair and Saanen goat milk samples, including intensive and extensive nutritional regimes. Kefir samples were produced with natural kefir grains (2%). Chemical properties (pH, titration acidity, total solids, fat, protein and ash), vitamin (A, E, B1, B2, B3, B6 and C) and mineral (Na, K, Ca, Mg, P, Fe, Zn, Se, Cu and Mn) compositions were analyzed using liquid chromatography.Kefir made from hair goat milk had a higher content of proximate values and vitamin–mineral composition. Local (indigenous) breed hair goat milk exhibited important nutritional and functional properties, including high contents of protein, fat, total solids, vitamins and minerals. This study demonstrated that feeding conditions, breeds and fermentation have significant influences on vitamin–mineral contents of milk and kefir. Both the extensive feeding regime and breeding led to enhanced concentrations of fat-soluble vitamins in milk.