Total antioxidant capacity and phenolic content of pasteurized and UHT-treated cow milk samples marketed in Turkey

In this study, UHT-treated (a total of 39 samples with 17 full-fat, 17 semi-fat and 5 skim milk) and pasteurized (5 fullfat) milk samples from different trademarks were obtained from national market chains, which constitute the majority of the Turkey’s pasteurized and UHT milk market. Total antioxidant capacities and phenolic contents of milk samples were determined by the 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and Folin-Ciocalteu (FC) methods, respectively. Mean total phenolic contents of milk samples ranged from 505.46±16.66 to 982.14±168.42 mg gallic acid equivalents (GAE)/L. Statistical results of the ABTS assay indicated that total antioxidant capacities in decreasing order were pasteurized [280.25±7.71 μM Trolox Equivalent (TE)] > full-fat (240.30±15.71 μM TE) > skim (216.78±4.90 μM TE) > semi-fat (209.81±7.03 μM TE) milk samples. In general, total antioxidant capacity of milk samples determined by the Folin-Ciocalteu method increased with an increase in milk fat content. Antioxidant capacity of pasteurized milks determined by both methods was higher than UHT processed milks.