Effects of four different drying methods on the carotenoid composition and antioxidant capacity of dried Gac peel

BACKGROUND Gac fruit (Momordica cochinchinensis Spreng.) is a rich source of carotenoids for the manufacture of powder, oil and capsules for food, cosmetic and pharmaceutical uses. Currently, only the aril of the Gac fruit is processed and the peel, similar to the other components, is discarded, although it contains high level of carotenoids, which could be extracted for commercial use. In the present study, four different drying methods (hot‐air, vacuum, heat pump and freeze drying), different temperatures and drying times were investigated for producing dried Gac peel suitable for carotenoid extraction. RESULTS The drying methods and drying temperatures significantly affected the drying time, carotenoid content and antioxidant capacity of the dried Gac peel. Among the investigated drying methods, hot‐air drying at 80 oC and vacuum drying at 50 oC produced dried Gac peel that exhibited the highest retention of carotenoids and the strongest antioxidant capacity. CONCLUSION Hot‐air drying at 80 oC and vacuum drying at 50 oC are recommended for the drying of Gac peel. © 2016 Society of Chemical Industry