• Journal of the Korea Convergence Society
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• v.13 no.3
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• pp.345-352
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• 2022

To increase the added value of peaches and utilize overproduced peaches, it is necessary to develop peach raw materials in various forms. In this study, usefulness of juice as raw material for vinegar was investigated by comparing and analyzing the characteristics of the traditional fermented vinegar prepared with 4 types of juice (fresh, refrigerated, boiled and frozen puree). Sugar content (6.20~6.50°Brix), total acidity (5.25~5.61%), pH (3.42~3.74), and acetic acid content (48.81~54.29 mg/mL) of the vinegar were all similar to existing traditional fermented vinegar. However, contents of total phenol and flavonoid were higher in vinegar prepared from refrigerated and boiled juice. Therefore, it was confirmed that boiled and refrigerated juice are very suitable as raw materials for traditional fermented peach vinegar, in particular, it was confirmed that boiled juice with a high content of total phenol and flavonoid can be used as a high value-added functional material. These results are considered to be important guidelines for developing high value-added raw materials for peaches.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.6
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• pp.804-808
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• 2011

We studied the antioxidant activity of Suaedajaponica, found in Korean mud flats. A 70% ethanol extraction yielded 9.74%. The 70% ethanol extract was further fractionated with hexane, chloroform, ethyl acetate, butanol, and water. The water fraction resulted in the highest extraction yields, but the ethyl acetate fraction resulted in the highest total phenol content and also total flavonoid content. The antioxidative activity of the fractions was evaluated using several methods and compared to commercial antioxidants. The scavenging activities of the hydroxyl radical, hydrogen radical, hydrogen peroxide, and xanthine oxidase of the ethyl acetate fraction were equivalent to that of BHA. The scavenging activities of the hydroxyl radical, hydrogen peroxide, and xanthine oxidase of the ethanol extracts were approximately 80~90% of that of BHA.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.6
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• pp.1009-1015
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• 2000

Fermentative and antioxidative characteristics of red mustard leaf (RML) kimchi, a traditional, fermented Korean vegetable food, were investigated. For the study, RML kimchi was made of RML, with green onion, red pepper, garlic, ginger, and sugar, and fermented at 15$^{\circ}C$. The pH was decreased and total acidity was increased during fermentation. The contents of reducing sugar, total vitamin C, and total Phenol content were 2.36%, 65 mg%, and 59 mg% at the initial stage. Although the content of reducing sugar decreased gradually during fermentation, however, the quantity of ascorbic acid decreased with the tendency of slightly increased at 6 days, and the amount of total phenol was increased. CIE L*, a*, b＊values were increased until 6 days of the fermentation. In order to determine the antioxidative activity of RML kimchi itself, the model systems of RML kimchi were made with cooked beef. TBA values of RML kimchi which was fermented for 6 days showed the lowest level in model systems. Water, n-hexane, methanol extracts of RML kimchi had a considerable antioxidative activity with the inhibition of formation of peroxide during the autoxidation of linoleic acid mixtures in aqueous model systems.

• Food Science and Preservation
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• v.15 no.4
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• pp.593-597
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• 2008

This study was performed for obtaining optimal extraction conditions to produce peach liqueur containing chitosan. Alcohol content of unsliced fruits was the largest recording 30% after extracting for 8 weeks and those of fruits sliced into four pieces were high recording around 28% after extracting for $6{\sim}8$ weeks. Sugar content was $11{\sim}13^{\circ}Brix$, total acidity was around 0.2% and pH was about 4.8. While soluble solids content was around 2.8% in unsliced fruits with a little change of the content, those of fruits sliced into four pieces were ranged from 2.8% to 3.1% and showing a tendency that longer extraction time increased the content. Brownness of unsliced fruits and fruits sliced into four pieces were $0.33{\sim}0.54$ and $0.56{\sim}0.73$ respectively. Total phenol content showed a similar tendency with brownness and the total phenol content of sliced fruits was higher than that of unsliced fruits by only around 0.2 mg%. When peach liqueur was made by extracting unsliced fruits massively by following conditions set above, methanol content grew with longer extraction time but the difference was not significant and the content was detected to be extremely small recording about 50 ppb. Among organic acids, oxalic, malic and citric acids were found, and fructose, glucose, sucrose and maltose were detected as free sugars. In conclusion, extracting unsliced fruits for 8 weeks as extraction conditions showed an excellent quality in overall for peach liqueur containing chitosan.

• Food Science and Preservation
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• v.11 no.1
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• pp.88-93
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• 2004

This study was conducted in order to compare reflux extraction(RE) and microwave-assisted extraction(MAE) in extraction efficiency and establish optimum microwave extraction conditions in obtaining Aster scaber Thunb extracts. Extraction time was reduced considerably in MAE. When 70％ methanol, 50％ methanol, 70％ ethanol, or 50％ ethanol was used, no difference was found in the amount of soluble solid and total phenol between MAE and RE. The optimum microwave-assisted extraction conditions for Aster scaber Thunb were achieved by 120-150 watts of microwave energy and 4∼8 minutes of extraction time. No significant changes were found in antioxidant activity using DPPH scavenging method over the variation of microwave power or extraction time. The use of diluted methanol or ethanol improved soluble solid content(30.8％), total polyphenol content(2.9％) and antioxidant activity(69％ ).

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1038-1040
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• 2001

This study was conducted to investigate the constituents of pumpkin, to develop of health food using pumpkin. Crude protein contents of skin (19.82%) and fiber (16.43%) were higher than that of flesh. Crude lipids contents of skin (2.84% ) was higher than those of flesh and fiber. Major free sugars in pumpkin were sucrose, fructose and glucose. Total sugar contents in the flesh was higher than that of fiber. This tendency was opposite to reducing sugar contents. Also, free sugar contents in pumpkin were flesh (30.19 mg/100 g), fiber (22.99 mg/100 g) and skin (15.67 mg/100 g), respectively. The total Phenol and carotenoid contents in 100 g of fiber revealed 379.8$\pm$9.76 mg and 43.71$\pm$1.46 mg, corresponding to 47% and 62% of the total phenol and carotenoid contents of pumpkin. Total flavonoid content in 100 g of skin revealed 81.5$\pm$3.56 mg.

• 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 Nutrition and Health
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• v.37 no.1
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• pp.38-44
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• 2004

Food irradiation has been steadily increased in many countries concomitantly with increasing international trades and concerns about naturally occurring harmful contaminants of food. Although, irradiation provides an excellent safeguard for the consumer by destroying harmful bacteria, it would be necessary to investigate nutritional adequacy of irradiated foods with a special emphasis on such foods as red pepper powders, cold-water fishes (mackerel), sesame seeds that are widely consumed in Korea. These food items are of special concern due to the fact that most of them are imported and that several nutrients contained in them are sensitively reacting to irradiation. We observed changes in the antioxidant nutrients contents, such as vitamin A, $\beta$-carotene, vitamin C and total phenol, and also vitamin B$_1$ in the foods that were irradiated at different dose levels. The nutrients contents in red pepper were respectively 98.6% and 92.3％ for total phenol, and 97.8% and 94.5% for $\beta$-carotene, right after irradiation at the dose of 10 and 20 kGy. The vitamin C contents decreased with irradiation doses up to 76.4% (10 kGy) and 68.5% (20 kGy) and B$_1$ contents decreased to 54.9% and 80.7% of non irradiated red pepper. When the mackerel was irradiated at the applied dose of 3 and 7 kGy, total phenol concentration of the irradiated fish was respectively 91.3% and 94.2% of non irradiated fish. The amounts of vitamin A were 82.6% (3 kGy) and 78.0% (7 kGy) of unirradiated sample and vitamin B$_1$ contents reduced to 30.5% and 51.5%. $\alpha$-Tocopherol content was 33.9% of the non-irradiated one when it was irradiated at 7 kGy. Vitamin A and ${\gamma}$-tocopherol contents in sesame seeds linearly decreased with the applied doses (5 and 10 kGy) Vitamin A contents decreased up to 87.8% (5 kGy) and 82.9% (10 kGy) and that of ${\gamma}$-tocopherol were 72.4% and 66.5% of the unirradiated sample.

• 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.

• Korean journal of food and cookery science
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• v.21 no.4 s.88
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• pp.433-439
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• 2005

Soybean is an important plant as it is the source of protein and oil as well as various phytochemicals that are related with biological activity. Over the past decades, scientists have conducted considerable research on the physiological properties of soybeans, especially isoflavones, which are the characteristic components in soybeans. However, there is no research on the properties or the bio-functionality of soybean leaf. Jangachi and kimchi are two of the traditional special dishes of Gyungsang Province in Korea which we made from soybean leaves. Depending on the recipe, green or yellow soybean leaves are used for the preparation of these two side dishes. We compared the antioxidative activity and measured the contents of isoflavones, total phenol, chlorophylls, carotenoids, and vitamin C in the ingredients (green and yellow soybean leaf) and the final side dishes (jangachi and kimchi). We Int report that isoflavones were contained in soybean leaf and that jangachi had the highest isoflavone contents among the samples. Yellow soybean leaf contained higher isoflavones than green soybean lear and kimchi. From the TEAC assay results, the sequence or antioxidative activities was yellow soybean leaf > soybean leaf jangachi > green soybean leaf > soybean leaf kimchi. The sequence was the same with total phenol contents, indicating that antioxidative activity is highly related with total phenol level. Chlorophylls, carotenoids and vitamin C existed abundantly in green soybean leaf. In conclusion, soybean leaf could be a good material for health due to the presence of isoflavones and the other useful antioxidants mentioned above.