29B-15 |
Effect of cooking treatment on antioxidative properties of broccoli |
C. Y. CHANG, C. H. Lin, and S. H. Chiang. Bioindustry Technology, Da-Yeh University, 112, Shan-Jiao Rd., Dah-Tsuen, Chang-Hwa, 515, Taiwan Vegetables play an important role in human diet. Many researches reported that the uptake amount of Cruciferous vegetables has a strong correlation with cancer prevention and inhibition. The detailed mechanism has not been fully realized. However, the high amount of antioxidants in vegetables reducing the possibility of tumor formation was confirmed. Studies of the antioxidative properties of Cruciferous vegetables are mostly focused on the fresh ones. The effect of processing on the antioxidative properties of Cruciferous vegetables is seldom reported. In this research, The broccoli (Brassica oleracea L var italica Plenck) was used as materials and sampled as four groups, including fresh, precooked (50¢J, 10 min), cooked (boiling, 8 min), and precooked-cooked, to investigate the effect of cooking treatment on the textural change of broccoli. These four samples after freeze drying were extracted using methanol, and the antioxidative properties of extracts were measured and compared with those of alpha-tocopherol and butylated hydroxyanisole (BHA). Data showed the reducing power of the extracts from precooked, cooked, and precooked+cooked broccoli had high reducing power, which was higher than those of alpha-tocopherol and BHA, and was 1.5~1.7 times as high as those of alpha-tocopherol and BHA. The extracts from fresh and precooked broccoli had the highest ferrous ion chelating power of 90.5%. The extracts of these four samples also showed high values of scavenging activity, which were 96.8, 97.3, 98.6 and 97.9% and were close to those of alpha-tocopherol and BHA. The extract from direct cooked broccoli had the highest inhibitory effect among these four samples, however, which was only 0.4 times as high as those of alpha-tocopherol and BHA. The results of this research reveal that the broccoli after cooking treatment also shows a strong antioxidant power. It may be still helpful for human health from the antioxidation standpoint.
Session 29B, Food Chemistry: Lipids, antioxidants and emulsifiers
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