Microwave pre-treatment improved antioxidant activities of Brassica seeds, cold-pressed oil and cake

摘要

In order to analyze microwaving effects on antioxidant activities of seeds, oil, pressed-cake, and defatted-meal in cold pressed process, 3 species of Brassica (B. napus, B. juncea and B. rapa) seeds were treated in microwave oven at 560 W for 7 min. Antioxidant activities of samples from untreated seeds and 7-min microwaved seeds were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, ferric reducing antioxidant power (FRAP) method, and β-carotene bleaching (BCB) test. Results showed that microwave pre-treatment increased free radical scavenging activities (RSA), total antioxidant activities (TAA), and coefficient of antioxidant activity (CAA). Antioxidant activities of 7-min microwave pre-treated cold pressed oil were significantly higher than those of untreated ones due to increasing canolol content. Furthermore, microwave enhanced antioxidant activities of B. napus seeds more effectively than those of the other 2 species. This research provided better understanding for microwave pre-treatment application in antioxidant activity improvement of cold pressed oil.