Comparative antioxidant potential of kefir and yogurt of bovine and non-bovine origins.

The aim of this study was to compare the antioxidant potential of the yogurt and kefir produced from ewe, camel, goat, and cow milk. The antioxidant activity of the samples was assessed by measuring total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, ferric reducing antioxidant power (FRAP) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical reducing capacity during 20-day storage at 4 ºC. Kefir and yogurt prepared from ewe and camel milk had significantly higher antioxidative potential than samples made from goat and cow milk (P < 0.05). Ewe kefir (74.55-80.11 mg GAE 100 mL-1) showed the highest TPC followed by cow kefir (65-73.15 mg GAE 100 mL-1), camel kefir (61.2-69.91 mg GAE 100 mL-1) and goat kefir (58.31-73.5 mg GAE 100 mL-1) (P < 0.05). Camel yogurt possesses the highest TPC (56.5-68.25 mg GAE 100 mL-1) followed by ewe (40.32-46.5 mg GAE 100 mL-1), cow (29.5-35.5 mg GAE 100 mL-1) and goat (20.03-26.85 mg GAE 100 mL-1) yogurt (P < 0.05). According to DPPH, FRAP, and ABTS results, the antioxidant activity of samples was as follows in descending order: ewe kefir, camel kefir, ewe yogurt, camel yogurt, cow kefir, goat kefir, goat yogurt, cow yogurt. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13197-021-05139-9. © Association of Food Scientists & Technologists (India) 2021.