• Korean journal of food and cookery science
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• v.26 no.1
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• pp.79-87
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• 2010

The antioxidant activity of hot water extracts made from Yuza (Citrus junos SIEB ex TANAKA) cultivated in Namhae Changseon, Seolcheon and Idong-myeon was analyzed. The total phenolic compound content was significantly higher in the Seolcheon sample (116.06 mg/100 g) than in Idong or Changseon. Flavonoids and hesperidin contents were not significantly different among samples. The electron-donating ability of the Yuza peel hot water extracts was activated to over 55% in all samples with $5,000\;{\mu}g/mL$ added to the reaction system, with especially high in the Seolcheon sample (85.70%). Also, the reducing powder in $10,000\;{\mu}g/mL$ added to the reaction system was showed significantly higher in the Seolcheon (0.82) than in the other samples. The ABT cation decolorization capacity of Yuza peel extracts was activated to over 50% in all samples when $5,000\;{\mu}g/mL$ of water extracts were added to the reaction mixture, and the activity was the highest (67.59%) in the Idong samples. The nitric oxide scavenging activity was lower than 45% in all samples, with the activity of Changseon significantely lower than the other samples. The antioxidant activity of the $\beta$-carotene linoleic acid system was 33.30~42.22% when $1,000\;{\mu}g/mL$ water extracts was added to the reaction mixtures, of which the activity in the Yuza cultivated in Seolcheon showed the highest.

• Applied Biological Chemistry
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• v.51 no.3
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• pp.194-199
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• 2008

The biological activities of water and ethanol extracts from different fruit parts, such as peel, flesh, and placenta of oriental melon were investigated. The total phenolic concentration of water extract was the highest such as 151.64 ${\mu}g/g$ in the peel, also that of ethanol extract was 224.77 ${\mu}g/g$ in the peel, respectively. The total flavonoid content in the water and ethanol extracts were high such as 45.53 ${\mu}g/g$ and 67.16 ${\mu}g/g$ of peel, respectively. In the physiological activities, DPPH in the water and ethanol extracts were high such as 25.0% and 83.3% of peel in 1% concentration. Extract of peel was higher than those of flesh and placenta. ABTS in the water extracts was 79.2% of peel, 57.6% of flesh and 74.0% of placenta in 1% concentration. Ethanol extracts was 99.9% of peel, 52.1% of flesh and 41.2% of placenta in 1% concentration. In addition, xanthine oxidase inhibitory activity and ${\alpha}$-Glucosidase inhibition activity of the peel of water and ethanol extracts appeared to be higher than those of placenta and flesh. This study showed that the antioxidant and ${\alpha}$-Glucosidase inhibition activity of peel extracts were higher than those of placenta and flesh. Also, the antimicrobial effect of ethanol extract from different fruit parts was shown only on Streptococcus agalactiae.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.2
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• pp.243-249
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• 2014

Cheonggukjang was manufactured using three different kinds of soybeans, after which changes in the content of phytoalexins such as trans-resveratrol (3,5,4'-trihydroxy-trans-stilbene) were measured. Along with phytoalexins, changes in the content of functional oligosaccharides such as stachyose and raffinose were also measured, and the corresponding antioxidant activities were studied. The content of trans-resveratrol was found to be higher in fermented beans than in raw beans. Generally, the content was higher as the fermentation period increased. After 48 hours of fermentation, the contents of trans-resveratrol were $50.06{\pm}0.82$, $39.04{\pm}0.49$, and $34.00{\pm}0.54{\mu}g/g$ (Nulchan, Daewon, and Taekwang), respectively, which is 4 times higher than the contents of raw beans. The contents of stachyose were $10.84{\pm}0.42{\sim}13.05{\pm}0.13mg/g$ in raw beans, $11.37{\pm}0.03{\sim}12.05{\pm}0.52mg/g$ immediately after boiling, and $0.16{\pm}0.01{\sim}0.33{\pm}0.02mg/g$ after 12 hours of fermentation, which is a 97% decrease from those of raw beans. After 24 hours of fermentation, no amount of stachyose was detected. The contents of raffinose were the lowest in raw beans at $2.66{\pm}0.09{\sim}3.54{\pm}0.05mg/g$, but they increased 3~4 times between boiling and 24 hours of fermentation to $10.61{\pm}0.16{\sim}12.66{\pm}0.17mg/g$. However, raffinose content tended to decrease to $8.28{\pm}0.17{\sim}11.83{\pm}0.44mg/g$ after 48 hours of fermentation. From FRAP, DPPH, and ABTS assays, antioxidant activities according to fermentation period of Cheonggukjang were rather low in boiled soybeans compare to raw soybeans. However, the activities were higher as the fermentation period increased. The antioxidant activity of trans-resveratrol showed an $RC_{50}$ value of $4.71{\pm}0.36{\sim}8.46{\pm}0.05{\mu}g/mL$ from the DPPH, ABTS, and FRAP assays. This could be partly due to the significant increase in trans-resveratrol according to fermentation periods. However, changes in functional oligosaccharides (stachyose and raffinose) during fermentation appear to not be related to the antioxidant effects of Cheonggukjang.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.3
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• pp.315-320
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• 2006

For the purpose of developing natural antioxidant, the antioxidative and antimicrobial activities of phenolics isolated from spices were determined. The total phenolics contents of spices were more than 20 mg/g in water and 60% ethanol extracts of all spice, oregano and sage. Electron donating ability assay showed high inhibition rate in water extracts of all spice, nutmeg, white pepper, oregano and sage and 60% ethanol extracts of oregano and nutmeg. Antioxidant protection factor (PF) was higher than 1.2 in 60% ethanol extracts of sage, all spice and oregano and water extracts of sage. The 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid radical decolorization (ABTS) was inhibited by more than 90% by water and 60% ethanol extracts of all spice and oregano. TBARS (thiobarbituric acid reactive substances) were $0.7{\mu}M$ in the control and $0.2{\mu}M$ in water and 60% ethanol extracts the each spices. The water extracts of each spices did not have antimicrobial activity against H. pylori; however, the 60% ethanol extracts from oregano revealed the high antimicrobial activity as clear zone of 10 mm and inhibition rate of 77.2% with $200{\mu}g/mL$ of phenolics content. The result suggests that spices extract may be useful as potential sources of anti-Helicobacter pylori, antioxidant.

• Food Science and Preservation
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• v.21 no.1
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• pp.97-106
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• 2014

This study was performed in order to investigate the anti-obesity effect of Polygala tenuifolia on lipid mechanism in 3T3-L1 adipocytes. The chemical composition of the P. tenuifolia was analyzed in order to assess its nutritional value. Total dietary fiber was the highest among the proximate component of the P. tenuifolia. These results showed that the P. tenuifolia may be used as a potential functional ingredient for anti-obesity effect. Intracellular lipid droplets in the adipocyte were stained with oil-red O dye and quantified. In comparison to the control, lipid accumulation was significantly decreased by 40.1% and 22.4% when treated with the water extract and 70% EtOH extract of the P. tenuifolia at the concentration of $10{\mu}g/mL$, respectively. The anti-adipogenic effect of the water extract was stronger than that of the 70% EtOH extract. The gene expression levels were measured via Western blot and real-time PCR. As a result, the water extract was found to have decrease the gene expression of SREBP-1c, PPAR, $C/EBP{\alpha}$, FAS, ACC in a dose-dependent manner. These indicate that the water extract inhibits pre-adipocyte differentiation and adipogenesis by blocking the SREBP-1c gene expression in 3T3-L1 cells. Therefore, P. tenuifolia can be used as an effective anti-obesity agent.

• Applied Biological Chemistry
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• v.49 no.3
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• pp.243-247
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• 2006

The biological activity of functional food source with thyme extracts were examined. Total phenol contents in the 60% ethanol extracts $(26.8{\pm}0.35\;mg/g)$ with thyme leaf was higher than water extracts $(25.7{\pm}0.20\;mg/g)$. This HPLC analysis is significant in that physiological activity is related with phenolic compound content such as rosemarinic acid, quercetin and chlorogenic acid. Electron donating ability was shown as 90.1% in the water extracts and 77.7% in the 60% ethanol extracts. Antioxidant protection factor of 60% ethanol extracts was higher than water extracts. Helicobacter pylori of the water extracts from thyme leaves did not have antimicrobial activity, but the 60% ethanol extracts revealed the high antimicrobial activity as 9 mm of clear zone in $50\;{\mu}g/ml$ of phenol content, 10 mm in $100\;{\mu}g/ml$, 13 mm in $150\;{\mu}g/ml$ and 16 mm in $200\;{\mu}g/ml$, respectively. Angiotensin converting enzyme inhibition activity showed no inhibition activity in 60% ethanol extracts but 39.9% inhibition activity in water extracts. Xanthine oxidase inhibition activity showed high inhibition activity at 73.5% in water extracts and 100% in 60% ethanol extracts. The result suggests the development of phenol compound in thyme as anti Helicobacter pylori, antioxidant and anti-gout agents.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.11
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• pp.1525-1531
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• 2011

Antioxidant activity and protective effects of extracts from Helianthus tuberosus L. leaves (HTL) on t-BHP-induced oxidative stress in human liver Chang cells were investigated. The total polyphenol and flavonoid content of the water and ethanolic extracts from HTL were 89.6${\pm}$1.96, 94${\pm}$2.03 mg gallic acid equivalent/g extract, and 65.1${\pm}$2.84, 54.6${\pm}$1.87 mg catechin equivalent/g extract, respectively. In addition, $IC_{50}$ values for 1,1-diphenyl-2-picrydrazyl (DPPH), alkyl, and hydroxyl radical scavenging activity of the water extracts were 0.010${\pm}$0.003 mg/mL, 0.014${\pm}$0.002 mg/mL, and 0.989${\pm}$0.003 mg/mL, respectively. Antioxidant activities of the extracts were also determined by ferric reducing antioxidant power (FRAP), 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity and reducing power. The HTL extracts showed a strongly inhibitory effect on lipid peroxidation by measuring ferric thiocyanate (FTC) and thiobarbituric acid (TBA) values. In an MTT assay on the Chang cells, the extracts showed a protective effect by increasing cell viability and decreasing ROS on t-BHP-induced oxidative stress in Chang cells. These results indicate that the HTL extracts possess an antioxidant activity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.12
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• pp.1826-1831
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• 2010

This study was carried out to examine the changes of the quality feature and antioxidant activity of grape by-products. This experiment was to arrange the basic data for developing a functional material using grape by-products which were useless resources. Hot-air and freeze drying were followed by the gamma irradiation of 1~20 kGy. Hunter's color value, in case of hot-air drying, showed the highest L and a value in the 3 kGy, and it decreased according to the increase of the exposure dose. In the case of fre ze drying it showed the highest L and b value at the highest exposure, 20 kGy. It was considered that the breakdown of the pigment through high temperature processing was launched and the influence according to the gamma irradiation was not shown. The gamma irradiation of 3 kGy appeared to have a good influence on the color of the grape by-products which went through hot-air drying. The contents of the total phenolic compounds, in case of hot-air drying, showed the highest total polyphenol contents in the 3 kGy irradiation and it decreased according to the increase of the exposure dose; in contrast, the higher phenolic contents showed in the irradiated group than in the control. In case of freeze drying, the highest phenolic contents appeared in the control but 3 kGy showed the highest one in the irradiated group. Results of radical scavenging activity using DPPH and ABTS indicated that 3 kGy showed the highest radical scavenging activity in hot-air and freeze drying. Therefore, it was found that gamma irradiation of 3 kGy could improve the color and antioxidant activity of grape by-products, but an antioxidant activity of grape by-product due to the gamma irradiation was a little affected in the aspects of by-product utilization.

• Korean Journal of Food Science and Technology
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• v.50 no.1
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• pp.76-82
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• 2018

This study evaluated the physicochemical properties of a novel black bean milk yogurt made by lactic acid producing bacteria isolated from vinegar (Bacillus acidiproducens, BA) and kimchi (Lactobacillus plantarum, LP). Commercially available Lactobacilli mixture for yogurt (YF) were regarded as control bacteria. To investigate optimal conditions to make black bean yogurt, different types of bacteria (BA and LP) and dilution ratios of black bean milk and water (1:1, 1:1.5, and 1:2) were used. Titratable acidity and pH were affected by these dilution ratios, but not by the different types of Lactobacilli used. Titratable acidity and pH were lowest in the 1:1 diluted sample. The visible cell count, sugar content, and viscosity were significantly higher in the sample containing the black bean milk: water ratio of 1:1 than the rest of the samples. In the sensory test, black bean yogurt made with BA showed a higher overall acceptability score, similar to yogurt made with YF. In conclusion, black bean yogurt made by fermentation with BA and with 1:1 black bean milk:water dilution ratio was better than ones made with LP and at other dilution ratios.