Effect of ozone processing on anthocyanins and ascorbic acid degradation of strawberry juice

Strawberry juice samples were ozonated with processing variables of ozone concentration (1.6–7.8% w/w) and treatment time (0–10 min). Effects of processing variables on anthocyanins (P3G), ascorbic acid (AA) and colour values (L^∗, a^∗, and b^∗) were determined. Significant reductions in anthocyanin content (98.2%) and ascorbic acid (85.8%) were observed at an ozone concentration of 7.8% w/w and a treatment time of 10 min. The changes in lightness (L^∗) values and total colour difference (TCD) values were fitted well to zero-order kinetics, whereas, a^∗, b^∗ followed first-order kinetics. P3G and AA were fitted to first order and fraction conversion models. The rate constants for L^∗, a^∗, b^∗ and TCD were linearly correlated with ozone concentration, whereas, P3G and AA were exponentially related.