Effect of cooking methods on total phenolic and carotenoid amounts and DPPH radical scavenging activity of fresh and frozen sweet corn (Zea mays) kernels

摘要

We e valuate d t he effe ct of t hree differen t cookin g meth ods on antioxidant content and radical scavenging activity of s weet corn. Bo th fresh and frozen sweet corn kernels were boiled, microwaved, and stir-fried for 1, 3, and 5.min, respec-tively, then total phenolic (TP) and total carotenoid (TC) contents were determined by spectrophotometric methods. The free radical scavenging activity of the samples was determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The results showed that there was a significant increase in TP (1.2–1.9 times) and TC (1.1 to 1.8 times) content of fresh sweet corn after each co oking session for 1, 3, and 5 min, the same treatment of frozen corn resulted in 47–80% losses of TP and 10 to 39% losses o f TC content. The free radical scavenging activity (RSA) exhibited by cooked fresh and frozen sweet corns was found to be different, neither of them was very high, in the range of 70.2–78.6%, and the fresh cooked ones had higher.values of RSA