Antioxidant activity of ultrafiltered-Feta cheese made with adjunct culture during ripening

Six lactic acid bacteria strains previously isolated and fully identified from Motal cheese were used in ultrafiltered (UF)-Feta cheese as adjunct cultures. Antioxidant activity in cheese samples was evaluated on days 14, 28, 42 and 56 of the ripening period (5 degrees C). Cheese samples inoculated with L. brevis KX572376 (M2) showed the highest antioxidant activity, which was selected for further analyses. The highest DPPH radical scavenging and Iron (II) chelating activity of M2 cheese were 31.45% and 61.42%, respectively, which were observed on the 14th day of ripening. Fraction > 10 kDa showed more antioxidant activity than 5-10 and < 5. The electrophoretic pattern of water-soluble extract of M2 cheese also showed the presence of more bands above 10 kDa than the control sample (without adjunct culture). Peptide content in M2 samples was higher than the control samples. pH changes in M2 and control samples were different during ripening; while no significant difference was observed in the sensory properties. This study showed the ability of L. brevis KX572376 (M2) to produce functional UF-Feta cheese.