Manufacture and characterization of kefir made from cow and buffalo milk, using kefir grain and starter culture

Abstract

The microbiological and chemical characteristics as well as organic and amino acid profiles of kefir samples made from cow and buffalo milks fermented by kefir grains and starter culture were investigated during storage for 21 d at 4°C. After incubation, lactic, acetic, and citric acid concentrations showed a difference among the samples due to milk type and production methods. Storage time had little effect on the organic acid values of kefir samples. As compared with cow milk kefir, buffalo milk kefir had higher numbers of microorganisms, except lactobacilli, at the end of storage. Whereas pH and titratable acidity exhibited similar changes during storage in all kefir samples, ethanol levels were significantly increased in buffalo milk kefir samples. Glutamic acid was the major amino acid at all sampling times for all samples. Tyrosine, serine, histidine, alanine, methionine, and lysine concentrations were determined to be different in all samples depending on milk type. In general, due to the higher microbial population (especially yeast), kefir made from buffalo milk may be preferred.

Comparison of chemical, rheological and sensory properties of kefir produced by kefir grains and commercial kefir starter

“…The obtained values of TA ranged from 0.686±0.012 % (sample produced by kefir grains at 35 °C) to 0.808±0.048 % (sample produced by kefir grains at 25 °C) ( Table 1). Similar results (between 0.64 and 0.76 %) were obtained by Gul et al (2015) who examined chemical properties of kefir made from buffalo and cow milk using starter culture and kefir grains. Considering the influence of fermentation temperature, values of TA were significantly different in all samples (Table 1) indicating that the acid production took place in varying intensity whereby higher values were obtained at fermentation temperature 25 °C.…”

Assessment of antioxidant capacity by method comparison and amino acid characterisation in buffalo milk kefir

“…Gul et al . () determined that the major amino acids of buffalo milk kefir produced either by grains or starter culture were glutamic acid, alanine, serine, tyrosine, histidine, methionine and lysine. Amino acid contents from this study could contribute to proper understanding of the antioxidative properties of buffalo milk kefir.…”

“…The proteolytic activity of microorganisms, assimilation of peptides, and release of amino acids during fermentation result in the differences in the amount of free amino acids. Gul et al (2015) determined that the major amino acids of buffalo milk kefir produced either by grains or starter culture were glutamic acid, alanine, serine, tyrosine, histidine, methionine and lysine. Amino acid contents from this study could contribute to proper understanding of the antioxidative properties of buffalo milk kefir.…”

The effects of kefir grain and starter culture on kefir produced from cow and buffalo milk during storage periods

“…The acidity values of the kefir samples produced from buffalo or cow milk using kefir grains or starter culture ranged between 0.70 and 0.80% at the beginning of storage (p < 0.05) Gul et al (2015) reported higher values while Kezer (2013) reported similar values. Acidity values of the samples continuously increased during the 21-day storage (p < 0.05).…”

“…Buffalo milk contained higher dry matter, fat, and calories, and mineral, vitamins, and microelements than cow milk and had more nutritional value compared to other milk types thanks to its 7% to 9% fat content, high protein, high mineral content and partially low cholesterol ratio (Borghese, 2012). There are few studies on the use of buffalo milk in kefir production (Gul et al, 2015;Gul et al, 2018). Gul et al (2018) found in their study that buffalo milk kefir had higher viscosity and consistency index than cow's milk.…”