• Journal of the Korean Society of Food Science and Nutrition
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• 제38권4호
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• pp.490-495
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• 2009

This study investigated the changes of physicochemical characteristics and antioxidant activity of heated radish (Raphanus sativus L.). Raw radish was heated at various temperatures ($110{\sim}150^{\circ}C$) for 2 hr. The heated radish was extracted with 70% ethanol and then fractionated with hexane, ethyl acetate, and aqueous. Total polyphenol contents, $IC_{50}$ value of electron donating ability (EDA), and total antioxidant activity (AEAC) increased with increasing heating temperature. The maximum total polyphenol content was $256.26{\pm}9.61$ mg/100 g at $150^{\circ}C$ (control: $27.90{\pm}1.28$ mg/100 g), $IC_{50}$ value was $1.34{\pm}0.004$ mg/mL at $150^{\circ}C$ (control: $34.93{\pm}0.039$ mg/mL), and AEAC was $53.10{\pm}1.155$ mg AA eq/g at $150^{\circ}C$ (control: $6.721{\pm}0.122$ mg AA eq/g). The ethyl acetate fraction showed higher total polyphenol contents and stronger antioxidant activities than hexane and aqueous fractions. Total polyphenol content was 133.62 mg/100 g (at $140^{\circ}C$), $IC_{50}$ values of EDA and AEAC content were 0.39 mg/mL (at $150^{\circ}C$) and 183.72 mg AA eq/g (at $140^{\circ}C$), respectively.

• Korean Journal of Food Science and Technology
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• 제38권1호
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• pp.114-120
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• 2006

Anti-diabetic effects of extracts and fractions of Sasa borealis (SB), white lotus roots (LR) and leaves (LL), and their mixture were determined in 3T3-L1 adipocytes and Min6 cells by investigating insulin-sensitizing activity and glucose-stimulated insulin secretion, respectively. SB, LR, LL, and mixture of SB, LR, and LL (3 : 2 : 3) were extracted using 70% ethanol, and m mixture extract was fractionated by XAD-4 column chromatography with serial mixture solvents of methanol and water. Fractional extractions were utilized for anti-diabetic effect assay. SB and LR extracts increased insulin-stimulated glucose uptake, but not as much as mixture of SB, LR, and LL. Significant insulin-sensitizing activities of 20 and 80% methanol fractions of SB, LR, and LL mixture extract were observed in 3T3-L1 adipocytes, giving 0.5 or $5\;{\mu}g/mL$ each fraction with 0.2 nM insulin to attain glucose uptake level similar to that attained by 10 nM insulin alone. Similar to pioglitazone, peroxisome proliferators-activated $receptor-{\gamma}\;(PPAR-{\gamma})$ agonist, 20 and 80% methanol fractions increased adipocytes by stimulating differentiation from fibroblasts and triglyceride synthesis. LL extract and 20, 60, and 80% methanol fractions of the mixture suppressed ${\alpha}-amylase$ activity, but did not modulate insulin secretion capacity of Min6 cells in both low and high glucose media. These data suggest 20 and 80% methanol tractions contain potential insulin sensitizers with functions similar to that of $PPAR-{\gamma}$ agonist. Crude extract of SB, LR, and LL mixture possibly improves glucose utilization by enhancing insulin-stimulated glucose uptake and inhibiting carbohydrate digestion without affecting insulin secretion in vivo.