• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.12
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• pp.1746-1752
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• 2009

This study was carried out to compare the physicochemical characteristics of the tofu (soybean curd) with the additions of sorghum powder (SP). With increasing amounts of sorghum powder, the yields of tofu were increased. The tofu made of 5 and 7% (w/w) addition rates of SP gave the similar yields with that of control. Moisture contents of the tofu made of roasted sorghum powder after steeping for 15 hours (WR-SP) were higher than those of the control and the tofu made of roasted sorghum powder after washing (SR-SP) without steeping. The dietary fiber contents of tofu were higher in the SP-added tofu than control. The potassium contents increased with SP addition rates, while calcium and magnesium decreased. With increasing SP addition rates, hardness of the tofu decreased. With increasing amounts of SP, the L- and b-values of tofu decreased, whereas a-value increased. The total polyphenol, flavonoid and tannin contents, and ascorbic acid equivalent antioxidant capacity in the tofu extracts increased with increasing SP rates. Antioxidant components and activity were the highest in the tofu made of roasted sorghum powder after washing without steeping with the addition rates of 3-10%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.3
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• pp.320-326
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• 2012

This study was conducted to investigate the antibacterial and antioxidative activities of water and ethanol extracts from a mixture of roasted coffee and red ginseng. The antibacterial effects of each extract were determined by the classical paper disc method. A water extract of mixture samples inhibited growth of all strains, but antibacterial effects were mostly weakened. Ethanol extracts showed stronger antibacterial effects than water extracts in all strains except Gram negative Escherichia coli and the fungi strain Candida albicans. Also, the antibacterial effect of the Bacillus cereus strain appeared in all samples, and the ES2 sample formed a clear zone of 19 and 20 mm against Pseudomonas aeruginosa and S. Typhimurium respectively (MIC=0.25 and 0.125 mg/mL). Determinations of free radical elimination for the different mixture extracts using 1,1-diphenyl-2-picrylhydrazyl (DPPH) were compared with ascorbic acid and butylated hyderoxytoluene as positive controls. The water and ethanol extracts of mixture samples (100 ${\mu}g/mL$) showed 55.38~60.01% and 59.37~70.50% DPPH scavenging activities, respectively. DPPH scavenging activities of all mixture samples were slightly higher than roasted coffee and red ginseng samples. However, DPPH scavenging activity decreased when red ginseng extract composed more than 70% of the total extract. The total polyphenol in the mixture samples measured by the Folin-Denis method revealed the highest level of polyphenol content in ethanol extract of sample 3, whereas polyphenol content differed with different mixture ratios, ranging from 105.16~119.79 mg/g in ethanol extract. In the water extract, the polyphenol content was greatest with water extract of sample 1, whereas in other samples the content varied from 93.75~109.18 mg/g.