Degradation of carotenoids in orange juice during microwave heating

Degradation of carotenoids in orange juice was monitored during microwave (MW) heating at different time/temperature conditions. Various carotenoids were identified and quantified by HPLC. Degradation rate of carotenoids was influenced by MW heating temperatures: at 60 °C and 70 °C for 10 min violaxanthin and antheraxanthin were the compounds most unstable, while lutein and provitamin A carotenoids were more stable. At 85 °C a decrease of about 50% was observed for almost all carotenoids after 1 min of MW heating. Temperature sensitivity (z value) for total carotenoids was 14.2 °C, for single compounds z values ranged between 10.9 °C for β-carotene and 16.7 °C for antheraxanthin. These results can indicate an adequate choice temperature conditions for the quality control of carotenoids and the related nutritional values during MW treatment of orange juices.