The effect of (+)-catechin on total phenolic content (TPC) and antioxidant properties in low-fat hard cheese were examined over a 90-day ripening period at 8 °C. Antioxidant activity (AA) in cheese was measured by ferric reducing antioxidant power, oxygen radical absorbance capacity (ORAC) and 2,2-diphenyl-1-picrylhydrazyl assays and compared with TPC. Catechin retention coefficients in cheese curds were in the range of 0.63–0.75 and decreased the pH of cheese without affecting protein, fat or moisture content. Both TPC and AA increased during the 90-day ripening period. Oxygen radical absorbance capacity was the most suitable technique for evaluating AA in cheese due to the high correlation with TPC and suitability in both lipophilic and hydrophilic systems.