DEGRADATION KINETICS OF VITAMIN C AND β- CAROTNE IN MANGO JUICE

摘要

Kinetics study on Vitamin C and beta-carotene degradation in mango juice was examined. Ten (10) mango fruits (Mangifera Indica) of the common cultivar were selected for analysis; the fruits were allowed to reach approximately 75% of full ripeness. Sixteen (16) samples of the mango juice were pasteurized at temperatures of 60oC, 70 oC, 80 oC and 90 oC for 10, 20, 30, 40 minutes respectively, and kept under refrigerated conditions at 10 oC. The pH values at these periods ranged from 4.43-4.47. Results showed that both Vitamin C and beta carotene concentrations decreased with time following a zero order kinetic model. The highest R2 coefficient was 0.9955 in Vitamin C, while that of beta- carotene was 0.9872. The Arrhenius plots (Ink versus 1/T) showed the calculated activated energy Ea =12.192KJ/mol for Vitamin C. while the activation energy Ea = 19.097KJ/mol for beta-carotene. Hereto, heat treatment of mango juice should be carried out under low temperature conditions at short given intervals to retain the vitamin c and beta-carotene contents after juicing, during processing.