Antioxidant and α-glucosidase inhibitory activities of fresh bitter melon and change of charantin and lutein content upon brining and blanching treatments of pickling

초록

This study aimed to analyze charantin and lutein from fresh bitter melon (FBM) for their antioxidant and α-glucosidase inhibitory activities. We subsequently compared our results with charantin and lutein content of pickled bitter melon (PBM11, PBM13, PBM51, and PBM53), obtained by brining (1 and 5% salt) and blanching (1 and 3 min). Charantin, lutein, L-ascorbic acid, and total polyphenolic content in FBM were 777.92±27.59, 16.87±2.07, 94.78±0.61, and 22.07±0.74 mg catechin equivalents/g on dry basis, respectively. Antioxidant activity of 5 mg/L FBM extract was 31.76±0.42% in ABTS assay and 56.19±2.39% in DPPH assay; α-glucosidase inhibitory activity of 0.5 mg/L FBM extract was 55.60±1.34%. Charantin and lutein content of all PBM samples were higher than control without brining and blanching treatments, those in PBM53 being 375.63±9.03 and 4.07±0.40 mg/100 g, respectively. These showed that brining and blanching in pickling process were very effective in retaining charantin and lutein in bitter melon. © The Korean Society of Food Science and Technology.

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