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 degrees C and 70 degrees C for 10 min violaxanthin and antheraxanthin were the compounds most unstable, while lutein and provitamin A carotenoids were more stable. At 85 degrees 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 degrees C, for single compounds z values ranged between 10.9 degrees C for beta-carotene and 16.7 degrees 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. (C) 2010 Elsevier Ltd. All rights reserved.