Antioxidant Activities and Hardness of Black Persimmons Affected by Different Heat Treatments

The changes in hardness and antioxidant activities of black persimmons were investigated under 4 different heat treatment conditions (50 degrees C, 60 degrees C, 70 degrees C, 80 degrees C). The results demonstrated that when persimmons were transformed into black persimmons, the antioxidant activities of black mature persimmons were distinctly higher than that of fresh persimmons. The higher the temperature was, the stronger the antioxidant activity was. Among these 4 different heat treatment conditions, when the temperature was 70 degrees C, the black persimmons may be more suitable for food: the hardness of black persimmons was soft and elastic, the RP was 0.685, the DPPH RSA was 93.10%, and the SOD similarity activity was 6.96 U/g. Therefore, the heating treatment process could be a useful method for improving the antioxidant activity of black persimmons.