• Korean Journal of Food Science and Technology
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• v.47 no.2
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• pp.158-163
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• 2015

Fustin comprised >98 and 73.0-86.7% of the total flavonoid content in the bark, and the stems and lignum of Rhus verniciflua, respectively. The butein, fisetin, and sulfuretin content varied between 0.31-2.17, 0.27-3.32, and 0.15-0.80 mg/g on a dry weight basis, respectively, in different parts of Rhus verniciflua. The urushiol content was 5.09-6.29, 55.05-56.30, and 0.38-0.39 mg/100 g on a dry weight basis in the stems, bark, and lignum, respectively. This showed that the bark of the tree had the highest urushiol content. C15:3 (pentadecatrienyl catechol), C15:1 (pentadecenyl catechol), and C15:2 (pentadecadienyl catechol) comprised 63, 33-35, and 2-3% of urushiol congeners in the tree bark, respectively.

• Korean Journal of Agricultural Science
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• v.43 no.5
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• pp.723-733
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• 2016

Soybeans [Glycine max (L.) Merill] are a rich source of antioxidants and other phytonutrients. Soybean sprouts contain many biologically active secondary metabolites and are rich in polyphenols, flavonoids, and phenolic compounds. In the present study, two soybean cultivars, Hosim, with high oleic acid (- 80% in total seed oil), and Pungsannamul, with normal oleic acid (- 23%) in seed, were examined for changes in the content of crude protein, crude oil, total flavonoids, total phenolics, and DPPH (1,1-diphenyl-2-picryl-hydrazyl) during the sprouting duration of 5 days. The protein content in both the varieties was found to increase by the days of sprouting. The crude oil content of Pungsannamul sprouts was found to be maximum on day 1 (16.9%, w/w) and decreased thereafter to reach to the level of 14.8% on day 5. No significant differences in the crude oil content of Hosim sprouts from day 1 to 5 were observed. Flavonoid content was found to increase up to day 4 and then dropped on day 5, in both the cultivars. Total polyphenol content showed a tendency to increase up to day 3 and started to decrease significantly from day 4. DPPH activity was found to increase up to day 5 in both the varieties. All the components studied in the high oleic acid soybean sprouts showed a change in content during the sprouting process similar to the change that would occur in normal oleic acid soybeans. The study showed that the contents of antioxidant, flavonoid, and polyphenol significantly increase during the sprouting.

• Journal of Environmental Science International
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• v.26 no.8
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• pp.903-911
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• 2017

The purpose of this study was to measure the bioactivity and antioxidant activity of peel from Gardenia jasminoides fructus Ellis (GJE) in Namhae, Korea, following some established methods. CM (Chloroform:Methanol, 2:1, v/v), 70% ethanol, and n-butanol extracts were collected. Flavonoid content and value as a functional food ingredient of GJE peel was investigated through assessing antioxidant [DPPH (1,1'-diphenyl-2-picrylhydrazyl), ABTS (2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid)], and hydroxyl radical scavenging activities; superoxide dismutase like ability; ferrous ion-chelating capacity; and tannin content by solvent extraction. Solvent extract antioxidant activities significantly increased (p<0.05) at increasing concentrations (0.2, 0.4, 0.6 mg/mL). GJE peel extracts were less active than the positive control [ascorbic acid, BHA (butylated hydroxyanisole), and EDTA (ethylenediaminetetraacetic acid disodium salt dihydrate)]. Based on the results of this study, GJE peel could be used as a natural antioxidant source due to its high antioxidant activity and bioactive compound content.

• Preventive Nutrition and Food Science
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• v.21 no.2
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• pp.110-116
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• 2016

This study was performed to evaluate and compare the antioxidant substance content and antioxidant activities of white (Superior) and colored (Hongyoung, Jayoung, Jasim, Seohong, and Jaseo) potatoes. The potatoes were extracted with 80% ethanol and were evaluated for the total polyphenol, flavonoid, and anthocyanin contents and for 1,1-diphenyl-2-picrylhydrazyl (DPPH)/2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity, reducing power, and ferrous metal ion chelating effect. The total polyphenol, flavonoid, and anthocyanin contents of Hongyoung and Jayoung were higher than white and other colored potatoes. All colored potato extracts, except for Jaseo and Seohong, showed higher ABTS radical scavenging activities than the general white potato extract. Hongyoung and Jayoung had the highest ABTS and DPPH radical scavenging activities. Optical density values for the reducing power of Jayoung and Jaseo at concentration of 2 mg/mL were 0.148 and 0.090, respectively. All colored potato extracts had lower ferrous metal ion chelating effect than the white potato. A significant (P<0.05) positive correlation was observed between total polyphenol content and total flavonoid content (r=0.919), anthocyanin content (r=0.992), and ABTS radical scavenging activity (r=0.897). Based on these results, this research may be useful in developing the Hongyoung and Jayoung cultivars with high antioxidant activities.

• Journal of Nutrition and Health
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• v.51 no.6
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• pp.599-606
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• 2018

Purpose: Various plants, herbal medicines, and marine foodstuffs have been used in kimchi preparation to improve its overall quality. Teff, which is rich in minerals and starches, facilitates stable blood glucose levels and is well-suited for use in gluten-free products; hence, it can be used to reinforce the mineral composition of kimchi. In this study, we probed the antioxidant activities of hydrolysates prepared by treatment of brown teff with three proteases under different conditions. Methods: The mineral composition of brown teff was determined by inductively coupled plasma spectrophotometry-mass spectrometry, and we established optimal hydrolysis conditions by determining the total phenol and flavonoid contents of teff hydrolysates obtained using three different proteases (protamax, flavourzyme, and alcalase), two different protease concentrations (1 and 3 wt%), and three different incubation times (1, 2, and 4 h). The antioxidant activity of the hydrolysates was further investigated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, total antioxidant capacity (TAC), and ferrous reducing antioxidant power (FRAP) assays. Results: Brown teff was rich in I, K, Mg, and Ca, and the highest total phenol content ($24.16{\mu}g/mL$), total flavonoid content ($69.08{\mu}g/mL$), and TAC were obtained for 1 wt% protamax treatment. However, the highest DPPH scavenging activity and FRAP values were observed for hydrolysates produced by alcalase and flavourzyme treatments, respectively. Conclusion: Treatment of brown teff with proteases affords hydrolysates with significantly increased antioxidant activities and high total phenol and flavonoid contents, and these antioxidant activities of teff hydrolysates have the potential to enhance the quality and functionality of kimchi in future applications.

• Korean Journal of Medicinal Crop Science
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• v.14 no.5
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• pp.307-310
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• 2006

This study purposed to look for its uses by analyzing useful substances in kenaf (Hibiscus cannabin us L.) leaves based on the total polyphenol and flavonoid contents in the leaves, DPPH radical scavenging activity of leaf extract, SOD activity, etc. by different growth stage and variety. According to the results of experiment, the total polyphenol content was highest in Everglade-41 (27.9 mg/g dw.), the total flavonoid content was highest in Tainung-2 (42.3 mg/g dw.), and SOD activity was highest in Dowling (96.1 %). However, DPPH radical scavenging activity was similar among the three varieties.

• Food Science and Biotechnology
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• v.16 no.5
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• pp.828-831
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• 2007

We evaluated the effects of heat treatment on various properties of onion extracts (Allium cepa). Onion was heated at various temperatures ($110-150^{\circ}C$) for various times (1-5 hr), and the total polyphenol, flavonoid, and free sugar contents, and antioxidant activity were investigated. With increased heating temperatures and exposure times, the total contents of polyphenols and flavonoids, as well as antioxidant activity increased. The highest total polyphenol content (189.80 mg/100g) occurred after heating for 2 hr at $140^{\circ}C$. The highest total flavonoid content (252.51 mg/100g) occurred after heating for 3 hr at $150^{\circ}C$. The antioxidant activity assessed using the DPPH method was highest, at 2.1 mg/mL ($IC_{50}$ value), after heating for 2 hr at $150^{\circ}C$. Correlations between antioxidant activity and the total polyphenol, total flavonoid, and fructose contents were highly significant (all p<0.01). The optimal heating time and temperature were 2 hr and $130^{\circ}C$.

• Nutritional Sciences
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• v.3 no.2
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• pp.98-102
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• 2000

The purpose of this study was to evaluate the antioxidative potential of Korean wild leaf vegetables. Antixoidative activity of chamchwi (Aster scaber), nurucchwi (Pleurospermum kamtschaticum) sumssukbujengee (Aster glheni), moshidae (Adenophora remotiflora), spinach (Spinacia oleracea)k was evaluated as a reference for commonly used synthetic antioxidant, BHA. We compared the content of $\beta$-carotene, vitamin C and vitamin E as antioxidant vitamins, and total phenolic compound including flavonoid as non-vitamin compounds in Korean wild leaf vegetables and spinach. Thiobarbituric acid (TBA) value of Pleurospermum kamtschaticum, Aster scaber and Adenophora remotiflor was only 18-20% of control. TBA value of Aster glheni was 40% of control. On the basis of moles, the high level of vitamin C is the major contributor to the total antioxidant vitamin contents of Pleurospermum kamschaticum and Adenophora remotiflor. The amounts of flavonoid as well as total phenolic compound in Pleurospermum kamtschaticum and Adenophora remotiflor were also much higher than those of spinach. The amounts of flavonoid as well as total phenolic compound in Aster glheni were much higher than those of spinach while total amount of antioxidant vitamins was significantly lower than that of spinach. These results suggest that Pleurospermum kamtschaticum and Adenophora remotiflor could have antioxidative potency in food. Because of the higher content of antioxidant vitamins in Pleurospermum kamtschaticum and Adenophora remotiflor, these Korean wild leaf vegetables may have preventive effects on degenerative diseases, which have been associated with free radical mediated events.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.4
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• pp.578-581
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• 1995

The seasonal variation of two flavonoid, quercitrin and afzelin, in the leaves of Cedrela sinensis A. Juss. from May until November was investigated by high performance liquid chromatography. Separation by reversed phase chromatography on ${\mu}-Bondapak\;C_{18}$ column was achieved by isocratic elution. The concentration of quercitrin was 5.81% (w/w) in May and high in July(8.89%, w/w), August(7.94%, w/w), and decreased from September to November. The content of another flavonoid, afzelin was 0.06% (w/w) in May and highest in June (0.12%, w/w), and was reduced from July.

• Korean Journal of Food Science and Technology
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• v.53 no.1
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• pp.63-71
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• 2021

In this study, a comparative analysis was carried out between the 'Beta Tiny' and 'TY Nonari' cherry tomato cultivars harvested at the pink and red stages. Samples of the red stage were stored at room temperature for 9 days, during which physicochemical qualities, antioxidant compounds, and activities were measured. As cherry tomato ripening and storage progressed, firmness was reduced, whereas the lycopene content increased. Total phenolic content and antioxidant activity showed no significant changes as ripening and storage progressed; however, total flavonoid content of 'Beta Tiny' showed a significant increase (p<0.05). The main polyphenols in the two cultivars were identified as chlorogenic acid, rutin, and (-)-epigallocatechin gallate, among which chlorogenic acid showed a significant decrease (p<0.05) as ripening and storage progressed. A strong correlation was found between total phenolic and flavonoid content (R=0.744), and ABTS radical scavenging activity (R=0.975). Additionally, a negative correlation was shown by lycopene and chlorogenic acid (R= -0.934).