• Korean journal of food and cookery science
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• v.32 no.5
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• pp.575-584
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• 2016

Purpose: Nurungji is a traditional Korean food made by yellowish scorched rice. After getting gelatinization of rice, a thin crust of scorched rice will usually be left in the bottom of the traditional cooking pot. In this study, physicochemical characteristics and antioxidant properties of five commercial nurungji products (CNP1, CNP2, CNP3, CNP4, and CNP5) were evaluated. Methods: Physicochemical properties of the five commercial nurungji products were evaluated with AOAC method. The antioxidant activities were assessed using the 1,1-diphenyl-2-picryl hydrazyl (DPPH), 2,2-azinobis-(3-ethyl-benozothia zoline-6-sulfonic acid)(ABTS), ferric reducing antioxidant power (FRAP), and reducing power assays. Results: Water content was the highest in CNP3, followed by CNP1, CNP2, CNP5, and CNP4. Crude ash content of all nurungji was less than 1%. In Hunter color parameter, the significantly highest a value (redness) and b value (yellowness) were measured in the CNP4 product, meanwhile the lowest in CNP3 (p<0.05). The nurungji products of CNP4 and CNP5 had the significantly higher content in total polyphenols and total flavonoids, compared to those of other products. CNP3 and CNP2 had the lowest in total polyphenols and total flavonoids, respectively. CNP4 and CNP5 products showed the significantly higher values in antioxidant activities, whereas CNP3 had the lowest activity. Conclusion: The high value of antioxidant activities in CNP4 and CNP5 might have been affected primarily by the total polyphenols with increasing browning color during the heat treatment.

• Journal of the Korean Applied Science and Technology
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• v.33 no.2
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• pp.324-332
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• 2016

The objective of this study was to investigate the antioxidant activity of Korean yam (Dioscorea batatas $D_{ECNE.}$) by different extraction solvents including 70% methanol, 70% ethanol and chloroform-methanol mixture (CM, 2:1, v/v). Raw yam was analyzed for its color property, total phenol content and antioxidant activity. Yam possessed high $L^*$ value and $H^{\circ}$ value, which were $81.64{\pm}2.59$ and $83.36{\pm}0.15$, respectively. Raw yam was found to have great antioxidant activity evaluated through ABTS [2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] radical scavenging activity, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, reducing power, and ferric reducing antioxidant power. Total phenol contents of various extracts from raw yam increased in the following order: 70% methanol extract ($37.62{\pm}0.88mg\;CAE/g$), 70% ethanol extract ($43.38{\pm}0.66mg\;CAE/g$) and CM extract ($67.17{\pm}0.12mg\;CAE/g$), respectively. The same trend was also could be found in the ABTS radical scavenging activity, DPPH radical scavenging activity and ferric reducing antioxidant power assays. These results implied that Korean yam might play an important role in antioxidation and serve as the bio-health functional food to take a good part in prevention of human diseases and aging.

• Journal of the Korean Applied Science and Technology
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• v.32 no.1
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• pp.127-135
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• 2015

The aim of this study was to investigate the antioxidant activity of thermal treatment yam (Dioscorea batatas DECNE.) in Korea. Thermal treatment yam was extracted by different solvents including 70% methanol, 70% ethanol and chloroform-methanol mixture (CM, 2:1, v/v). Then color property, total phenol content and antioxidant activity were analyzed. Yam possessed high $L^*$ value and $H\limits^{\circ}$ value, which were $54.92{\pm}2.18$ and $73.20{\pm}0.77$, respectively. Thermal treatment yam exhibited great antioxidant activity evaluated by ABTS [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] radical scavenging activity, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, reducing power, and ferric reducing antioxidant power. Total phenol contents of various extracts from thermal treatment yam increased in the following order: 70% methanol extract ($63.53{\pm}0.33mg\;CAE/g$), 70% ethanol extract ($69.47{\pm}1.00mg\;CAE/g$) and CM extract ($97.49{\pm}0.66mg\;CAE/g$), respectively. The same trend was also could be found in antioxidant activity assays except for reducing power assay. These results implied that these extracts from thermal treatment yam might be useful to take a good part in prevention of human diseases and aging.

• Journal of Plant Biotechnology
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• v.48 no.4
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• pp.271-277
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• 2021

The present study aimed to assess and compare the quality characteristics and antioxidant activities of apple juice and blueberry juice at hourly intervals over a period of time based on the presence or absence of vacuum blending (0 and 800 hPa) using a household blender. Measurement of the dissolved oxygen content revealed that the removal rates of dissolved oxygen were approximately 83% and 86% in the apple and blueberry juice samples, respectively, after vacuum blending. Moreover, compared with general blending, there was little change in the antioxidant property and degree of browning over time with vacuum blending. Furthermore, hourly assessments revealed that the decrease in the polyphenol and flavonoid contents in the apple and blueberry juice samples was significantly lesser with vacuum blending for 3, 6, and 12 h than with general blending. Assessment of the change in ferric reducing antioxidant power (FRAP) activity over time revealed that the rate of decrease in FRAP activity over time was lower with vacuum blending than with general blending for both juice samples. ABTS and DPPH radical scavenging assays performed to determine the change in free radical scavenging activity revealed inhibitory activity at 0, 3, 6, and 12 h and confirmed that vacuum blending resulted in long-lasting antioxidant activities in both apple and blueberry juice samples. Taken together, the present results confirmed that vacuum blending is associated with superior quality maintenance and antioxidant properties in comparison with general blending.

• Journal of Environmental Science International
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• v.18 no.11
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• pp.1207-1214
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• 2009

Functional properties of Solanium nigrum-ethanol extract were investigated, nitrite scavenging ability(NSA) and antioxidant activities based on thiobarbituric acid(TBA) value were measured. The contents of potassium in fruit and root, calcium in leaf were the highest mineral components in each parts of Solanium nigrum. Total aromatics contents(TAC) was order of fruit>root>leaf, total flavonoid contents(TFC) in leaf was 6 and 10 times, total phenolic compounds contents(TPC) in leaf was 15 and 30 times of those in fruit and root, respectively, and TFC was high with TPC increase. NSA of leaf-ethanol extract was 61.9% on pH 1.2, 53.5% on pH 3.0, 54.8% on pH 4.0 and 14.3% on pH 6.0, where as NSA of root and fruit-ethanol were considerably low to 3.5~7.9% over pH 1.2~6.0. TBA value of soybean oil with the dosage of leaf-extract showed few differences from control within 3 days, but it fairly decreased with considerable antioxidant effect to 47.6% of the control in 8 days.

• Journal of Applied Biological Chemistry
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• v.60 no.3
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• pp.241-244
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• 2017

The antioxidant activity of various solvent extracts from Jeju camellia mistletoe (Korthalsella japonica (Thunb.) Engl.) was investigated using various in vitro assays as the 1,1-diphenyl-2-picrylhydrazyl radical scavenging, ferrous ion chelating and reducing power assays. Methanol and ethanol extracts showed the most potent antioxidant activity in all assays tested followed by water extract. The inhibitory effect of the Jeju camellia mistletoe extracts on pancreatic lipase and $\acute{a}$-glucosidase was also evaluated and the results showed that methanol and ethanol extracts markedly reduced both enzyme activities. Therefore, the methanol and ethanol extracts of Jeju camellia mistletoe is definitely worthy of further investigation for these beneficial effects on nutraceutical medicine.

• Journal of Microbiology and Biotechnology
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• v.30 no.11
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• pp.1706-1719
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• 2020

The objective of this study was to optimize the conditions for enhancing the antioxidant properties of sword bean (Canavalia gladiata) as a coffee substitute in two processing methods, roasting and grinding. The optimum conditions for removing off-flavor of the bean and maximizing functionality and efficiency were light roasting and cryogenic grinding (< 53 ㎛). In these conditions, extraction yield was 16.75%, total phenolic content (TPC) was 69.82 ± 0.35 mg gallic acid equivalents/g, and total flavonoid content (TFC) was 168.81 ± 1.64 mg quercetin equivalents/100 g. The antioxidant properties were 77.58 ± 0.27% for DPPH radical scavenging activity and 58.02 ± 0.76 mg Trolox equivalents/g for ABTS radical scavenging activity. The values for TFC and ABTS radical scavenging activity were significantly higher (p < 0.05) than in other conditions, and TPC and DPPH radical scavenging activity were second highest in lightly roasted beans, following raw beans. HS-SPME/GC-MS analysis confirmed that the amino acids and carbohydrates, which are the main components of sword bean, were condensed into other volatile flavor compounds, such as derivatives of furan, pyrazine, and pyrrole during roasting. Roasted and cryogenically ground (cryo-ground) sword beans showed higher functionality in terms of TFC, DPPH, and ABTS radical scavenging activities compared to those of coffee. Overall results showed that light roasting and cryogenic grinding are the most suitable processing conditions for enhancing the bioactivity of sword beans.

• Korean journal of food and cookery science
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• v.19 no.5
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• pp.624-630
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• 2003

The physicochemical properties and antioxidant activities of commonly consumed espresso and regular coffees, at coffee shops in downtown Seoul, were investigated. Moreover, the characteristics between chain type coffee shops and owner shops were compared using t-tests. The serving temperature and volume of espresso were lower than those for regular coffees. Whereas, the pH and total acidity of espresso were higher than those for regular coffees. Coffees from chain shops, in particular, had a significantly higher pH and lower total acidity than those from owner shops. The L, a and b values of the regular coffees were higher than those of the espresso coffees. With the exception of the a value of regular coffees, all the color values of the coffees from owner shops were higher than those from the chain shops. The intensity of the brownness, soluble solid contents and total phenolic contents of the espresso coffees were about 7∼8, 8∼9 and 4 times higher, respectively, than those of regular coffees. In addition, the free radical scavenging capacities and antioxidant activities of the espresso coffees, using a chemiluminescence assay, were higher than those of regular coffees. Espresso coffees from chain shops, especially, had higher activities of free radical scavenging than those from owner shops. In conclusion, the characteristics of coffees from chain shops were significantly different from those from owner coffee shops.

• Natural Product Sciences
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• v.28 no.3
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• pp.130-137
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• 2022

This study was conducted to characterise phytochemicals and to explore the biological activities of Vitex negundo leaves. The washed, course powder of V. negundo leaves were extracted with different solvents of increasing polarity. All the extracts were characterized and biological activities were compared. The results revealed that the ethanolic and cold water extracts showed the presence of all phytochemicals studied except protein compared to other extracts. Further, the quantitative estimation of phytochemicals showed that the ethanolic extract had highest yield and maximum amount of total polyphenols, flavonoids, and alkaloids with the least amount of tannins compared to other extracts studied. Furthermore, the highest total polyphenol content corresponds with the potent biological activities. Indeed, in vitro antioxidant and antisteroidogenic activities were highest in the ethanolic extract than others. To conclude, the present study is the first to report the characterization and antiandrogenic property of V. negundo leaf extracts. The ethanolic extract of V. negundo leaves can be used as an antioxidant and antiandrogenic agent. Hence, it can be considered for the treatment of hyperandrogenic conditions like polycystic ovary syndrome, etc.

• Journal of the Korean Society of Food Culture
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• v.23 no.6
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• pp.755-760
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• 2008

This study was carried out to investigate the quality characteristics and antioxidant activity of the black sesame Dasikadded spirulina (0, 10, 20, 30%). Black sesame Dasik with 30% spirulina showed a higher moisture content compared to control. L, a and b values of Hunter color system were decreased significantly according to the addition of spirulina (p<0.05). Hardness and gumminess analyzed by TPA (Texture profile analyzer) were increased significantly according to the addition of spirulina (p<0.05). The antioxidant property of black sesame Dasik increased according to the addition of spirulina: IC50 values of DPPH (1,1-diphenyl-2-picrylhydrazyl) and hydroxyl radical scavenging activity of the control was 112.3 g/mL and 56.2 mg/mL, respectively, whereas those of Dasik with 30% addition of spirulina was 58.2 mg/mL and 45.7 mg/mL, respectively. Sensory evaluation results showed that the overall acceptability was not significantly different up to 20% addition of spirulina, compared to that of the control. Based on these results, it was suggested that the addition of spirulina to black sesame Dasik was appropriated up to 20% for quality improvement with antioxidant activity.