• Korean Journal of Food Science and Technology
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• v.48 no.1
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• pp.15-19
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• 2016

Drying process was applied to increase the antioxidant activity of onion powder: freeze-drying or air-drying at 50, 70, and $90^{\circ}C$ and onion extracts were obtained from each powder using water or aqueous ethanol (50%) at $25^{\circ}C$ and $60^{\circ}C$. In the color analysis, the freeze-dried powders showed higher $L^*$ and lower $a^*$ and $b^*$ values than did the air-dried ones. The browning index of powders air-dried at $90^{\circ}C$ was significantly higher than that of freeze-dried powders or those air-dried at temperatures below $90^{\circ}C$. Phenolic content in the extracts was 4.02-23.12 mg gallic acid equivalent/g sample, and was the highest in the extract from the sample air-dried at $90^{\circ}C$, regardless of the extraction condition. The highest antioxidant activity, measured by 2,2-azinobis-3-ethylbenzothiazoline-6-sulfonic acid and 1,1-diphenyl-2-picrylhydrazyl methods, was found in the powder air-dried at $90^{\circ}C$, which induced browning. These findings indicate that antioxidant activity depends more on browning during drying than on extraction conditions.

• The Korean Journal of Food And Nutrition
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• v.24 no.3
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• pp.442-450
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• 2011

Numerous studies have suggested that dietary flavonoids contribute to prevent cardiovascular disease. Onion contains many functional phytochemicals such as quercetin. The aim of this study was to examine whether onion peel extracts supplementation affect blood lipid profiles and blood coagulation in animal model. Total 48 Sprague-Dawley male rats at 5 weeks old were divided into 6 groups with different diets(C: control, HF: high fat diet, HFOE 0.01%: high fat+onion peel extract 0.01% diet, HFOE 0.02%, HFOE 0.05%, HFOE 0.1%) for 8 weeks. Onion peel extract supplementation significantly decreased serum levels of LDL-cholesterol and increased HDL-cholesterol, while total cholesterol and triglyceride levels were not affected. Hematological parameters(hematocrit, white blood cell, red blood cell, and platelet count) and blood coagulation parameters(prothrombin time, activated partial thromboplastin time, thrombin time, and fibrinogen) were not significantly different among 6 groups. However, activated partial thromboplastin time of HFOE 0.05% group was significantly longer than that of HF group. These results indicate that onion peel extract supplementation displays hypocholestrolemic effects but does not seem to have anti-coagulation effects in high fat fed SD rats.

• Korean journal of food and cookery science
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• v.25 no.4
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• pp.395-405
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• 2009

In this study, a survey was conducted to determine consumer perceptions and satisfaction for onion hot-water extracts. Among the study subjects, females (53.3%) were in greater number than males, and individuals in their 40s (35.1%) made up the largest group. Cocerning the detailed efficacy of onion hot-water extracts, most respondents (84.5%) were aware of their efficacy and females recognized this more than males (p<0.001). Most consumers (67.3%) purchased onion hot-water extracts from 'health food stores prepared using a double boiler', and many consumers (47.4%) received information on the extracts from families and relatives. Of the respondents, 51.8% said they purchased 'quantities for $1{\sim}3$ months' at one time, and 33.1% stated that the price of onion hot-water extracts was expensive. They considered 'health' the most important aspect when purchasing, and preferred 'pouch packs' (60.3%) and considered 'easiness to open convenience to drink, and safety' (42.0%) the most important product features. Also, 62.8% of the respondents consumed onion hot-water extracts, and many drank them $1{\sim}3$ times a week, with '70 mL' as one dose, and drank them 'regardless of time'. The consumers were satisfied with the listing of health effects, but were not satisfied with the 'taste', 'smell', or 'color' of products. Concerning advertisements for the efficacy of onion hot-water extracts, 72.5% replied 'I trust them a little'. And concerning the expanding onion hot-water extract market, many respondents said it is difficult to choose an onion hot-water extract due to many similar products at the market. They also requested improvements of taste and flavor.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.4
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• pp.426-434
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• 2017

Physiological activities, including antioxidant activity, were examined in water and 80% ethanol extracts of leaf, stem, and root parts of Welsh onion. Total phenol and flavonoid contents were highest in both extracts of leaf and lowest in those of stem among parts of Welsh onion. 2,2-Diphenyl-1-picrylhydrazyl radical scavenging activity was highest in root among 80% ethanol extracts and in leaf among water extracts. 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging activity and reducing power were the highest in both extracts of Welsh onion leaf. Inhibitory activities against lipase in both extracts and ${\alpha}$-glucosidase in water extract were also highest in Welsh onion leaf. Alcohol dehydrogenase promoting activity was also highest in extracts of Welsh onion leaf. Both leaf and water extracts of stem only exhibited antimicrobial effects on Gram (-) Pseudomonas aeruginosa. This result implies that leaf is the most optimal part of Welsh onion as functional material, although stem and root parts of Welsh onion also exhibited physiological activity, including antioxidant activity.

• Journal of Life Science
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• v.18 no.7
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• pp.980-985
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• 2008

This study was carried out to develope an alcoholic drink by fermentation of onion extract using Saccharomyces cerevisiae. The optimal conditions for ethanol production were obtained by standing culture at $25^{\circ}C$ for 5 days with 5% inoculum volume. At the results by flask culture, the growth curve of used S. cerevisiae reached to the stantionary phase at 48 hr and the death phase at 90 hr, whereas ethanol production reached maximum at 114 hr. Under the above conditions, a large scale production was carried out. A standing culture in 5 l fermenter showed the similar results to its flask culture, but progressed 24 hr rapidly more than that of the flask culture. A fed-batch culture was performed by addition of the onionic medium supplemented with 10% (v/v) sucrose after 72 hr from the fermenting start. The fed-batch culture could prevent S. cerevisiae from entering into the death phase and maintain constant level of alcohol production. A continuous culture was able to carry out by adding per every 24 hr the onionic medium supplemented with 10% (v/v) sucrose after 72 hr from the fermenting start. Although S. cerevisiae used showed a little decreased growth, alcohol production maintained roughly the constant level at the maximum yield. To enhance the quality of this alcoholic drink, $2-O-{\alpha}-D-glucopyranosyl$ L-ascorbic acid (AA-2G) was supplemented into the onion extract of the substrate for fermentation. As resulted at this study, this alcoholic drink containing AA-2G should be used as a functional fermented alcohol drink strengthened with vitamin C.

• Nutrition Research and Practice
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• v.10 no.3
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• pp.364-364
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• 2016

• Horticultural Science & Technology
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• v.17 no.2
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• pp.123-126
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• 1999

Effects of garlic juice (GJ), ethanol- (GJAE) and ethyl ether extract of garlic juice (GJEE), onion juice (OJ) and ethanol extract of onion juice (OJAE), garlic juice+Merit Blue (GJ+MB), ethanol extract of garlic juice+Merit Blue (GJAE+MB), onion juice+Merit Blue (OJ+MB), ethanol extract of onion juice+Merit Blue (OJAE+MB), and Merit Blue (MB) on budbreak, flowering, and maturity of plastic house-grown 'Daebong' grapes (Vitis labruscana B.) were studied. MB alone and in combination with other formulae hastened the budbreak, and double application was more effective than single one. Most of the buds sprouted in early forcing, but percent budbreak in late forcing was very poor except for MB application. In early forcing, single application of MB in combination with other formulae was most effective for hastening flowering while the response to double application was not consistent, and even delayed the flowering except for OJAE, MB, and OJ+MB. In late forcing, single application of all dormancy-breaking agents, especially MB in combination with other formulae, hastened the flowering while flowering response to double application was inconsistent, and even delayed the flowering except for OJAE+MB and OJ. Although there were no significant differences in harvest date among treatments and the number of application in early forcing, single and double application of MB alone and in combination with other formulae, especially double application of OJAE+MB hastened the harvest date for 12 days in late forcing culture.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.4
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• pp.467-473
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• 2016

This study was designed to investigate whether consumption of onion wine can reduce serum biomarkers of ethanol-induced fatty liver in rats. Male Sprague-Dawley rats were initially trained for meal feeding to prevent reduction of food intake. After the training period, rats were weight-matched and assigned to the following three groups: 1) a control group fed a control liquid diet containing maltose-dextrin, 2) an ethanol group fed an ethanol liquid diet with 95% ethanol, and 3) an onion wine group fed the same ethanol liquid diet but containing onion wine extract at 1 mL/d/group. All three groups were fed daily for 6 weeks. At 0, 3, and 6 weeks, blood was collected via the orbital sinus following overnight food deprivation and terminally organs collected. Blood lipids and transaminase activities significantly increased in the ethanol-fed group but significantly reversed in the onion wine-fed group. The hepatic levels of fat and cholesterol at 6 weeks were significantly elevated by ethanol administration but significantly reduced by onion wine. These findings indicate that onion wine may ameliorate ethanol-induced fatty liver by lowering hepatic and blood lipid levels.

• Korean Journal of Food Science and Technology
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• v.50 no.4
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• pp.391-399
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• 2018

Bioconversion and fermentation of onion extract by lactic acid bacteria were carried out to enhance the bioavailability of quercetin through the increase of quercetin recovery and aglycone formation. Lactobacillus casei, L. plantarum, and Kluyveromyces lactis were selected as the optimum strains for bioconversion. The environmental conditions to maximize the conversion ratio between glycoconjugate and quercetin aglycone have been evaluated. The concentrations of quercetin after fermentation of onion slurry by K. lactis and L. casei increased to 260% and 318%, respectively; however, the quercetin concentrations decreased after 48 hours of fermentation. Additionally, the quercetin hexose concentration increased to almost 141%. Controlling the initial pH of the onion juice increased the lactic acid production by L. casei and L. plantarum by more than two-fold. Meanwhile, the concentration of quercetin hexose decreased rapidly with the increased production of aglycones. The scale-up experiments showed the same fermentation efficiency; however, thermal sterilization reduced the quercetin glycone concentrations drastically.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.4
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• pp.565-569
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• 2011

Validation of quercetin as a marker compound in the standardization of Changnyeong onion extract developed for functional health food was attempted by analytical method. The specificity was satisfied with retention time and photo diode array (PDA) spectrum by analysis of quercetin using HPLC and comparison with standard compound. It showed a high linearity in the calibration curve as coefficient of correlation ($R^2$) of 0.9986, and the limit of detection (LOD) and limit of quantitation (LOQ) were 0.2 mg/L and 0.5 mg/L, respectively. Recovery rate test with quercetin concentration of 0.05, 0.075 and 0.1 mg/mL was revealed in the high range of 82.36~95.26%, 82.70~98.24% and 87.91~95.11%, respectively. The intra-day and inter-day precision in quercetin for Changnyeong onion extracts was 0.10~3.28% and 0.96~5.79%, respectively. Therefore, application of quercetin was validated in analytical method as a marker compound in Changnyeong onion extracts.