Optimization of processing conditions to enhance antioxidant and carotenoid contents of carrot juice

Abstract

Carrot is one of the most widely consumed vegetables in the world. Its mild, sweet flavour lends itself to all kinds of combinations in the kitchen and appeals both to young and old alike. The main carotenoids found in carrots (raw, cooked or in juice) are beta-carotene, lutein and zeaxanthin. Carotenoids are compounds known for their antioxidant properties, i.e. they are able to neutralise free radicals in the body. Consumption of foods rich in carotenoids is thought to be linked to a lower risk of several diseases, such as cancer, cardiovascular diseases and certain diseases associated with ageing. The purpose of the present work was to determine how carrot pre-treatment (blanching with or without sonication, duration, and temperature) affected the antioxidant qualities of carrot juice. Carrots were blanched in ordinary and acidified water for 4, 6, 8, and 10 min at 80, 90, and 100 °C. The juice was extracted and sonicated for 2 min at 15 °C. After a preliminary study, a surface response methodology experimental design was conducted. The study’s results indicate that carrot juice treated with sonication for 2 min and blanched at 95 °C for 9 min had the highest yield of carotenoids and, therefore, the highest antioxidant activity. Based on these findings, we conclude that combining blanching with sonication is a practical option for the food industry to obtain the benefits of both processes.