Nutritional Characteristics and Antimicrobial Potential of Goat Whey Fermented with Kefir Grains

Abstract

The goat milk whey is interesting for the consumers of healthy and functional food. Whey nutritive value, better protein digestibility then the casein, participation in immune system activation, bactericide characteristics as well as positive influence in allergic reaction inhibition makes this beverage to be in demand in the market. The dairy industries that create large amount of whey have to introduce processes to recover all of the milk solids and this processes need to be cost-effective and environmental friendly. The aim of the present study was to evaluate the nutritional characteristics of commercial goat whey and its antimicrobial potential after fermentation with kefir grains. The samples of goat whey were collected from a market. The fermentation was carried out at a room temperature (25 ̊C) in time of 24 hours. Different quantities of kefir grains (2%, 5% and 10%) were used to perform the fermentation of the whey. The pH value, titratable acidity and percentage of lactic acid changed significantly (p<0.05) after the fermentation process while the other examined phisico-chemical characteristics shows insignificant changes. The antimicrobial potential of fermented beverage was performed by additional inoculation of strain cultures E.coli ATCC 8739 and coagulase positive Staphylococcus aureus ATCC9610. After 24 hours incubation at 37 ̊C, in whey fermented with 10% kefir grains, no growth of added strains was recorded. The antioxidant capacity of fermented whey was also analyzed. The results of TPC, reducing power and DPPH, show antioxidant potential of fermented goat whey and its possibility of protection against free radicals.