• Proceedings of the SOHE Conference
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• 1998.11a
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• pp.123-126
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• 1998

• Proceedings of KHEA Conference
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• 2005.10a
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• pp.114-114
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• 2005

• Food Science and Preservation
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• v.18 no.3
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• pp.310-318
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• 2011

The main objective of this study was to manufacture black onions using different methods, and to analyze the color and physiological and antioxidant activities of their water extracts. Black onions were produced via high-temperature aging (70, 80, and $90^{\circ}C$). At $90^{\circ}C$, onions with different weights (large, 90-L; medium, 90-M; and small, 90-S) and small onions with different appearances (whole, 90-S-W; cut, 90-S-C; and peeled, 90-S-P) were also produced. The colorimetry measurements showed that the extract from the 90-S-C black onion had the highest ${\Delta}E$ value among all the extracts from all the black onion groups. The extract from the 90-S-C black onion had a 3.3 times higher total phenol content than that from the $70^{\circ}C$ black onion extract (11.62 and 3.51 mg/g, respectively). The DPPH radical scavenging activities of the extracts from 90-S-W, 90-S-C, and 90-S-P were higher than those of the other black onion extracts, and the 90-S-C black onion extract had the highest level of 48.3% (at the concentration of 10 mg/ml). The 90-S-C black onion extract also had the highest level of antioxidant activities (ABTS radical scavenging activity, 0.84 mg AA eq/100 g, and nitrite scavenging ability, 49.8%). These results clearly demonstrated that 90-S-C was the best among the conditions used and that the water extract of the 90-S-C black onions had a significantly higher level of antioxidant activities than the extracts from the other black onions.

• Journal of Life Science
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• v.22 no.11
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• pp.1477-1486
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• 2012

This study was performed to determine the effect of onion peel extract using 70% ethanol and 95% ethanol on its anti-oxidation activity, small intestine length, and intestinal villi of high-fat fed mice. Five percent of each onion peel extract using 70% and 95% ethanol showed significant decrease of E. coli and Listeria monocytogenes. Total phenolic contents of onion peel extracts using 70% and 95% ethanol were $166.89{\pm}0.03$ mg/g and $160.89{\pm}0.13$ mg/g, respectively. In anti-oxidation activity, DPPH radical scavenging activity and SOD-like activity of onion peel extracts were higher at 100 ug/ml concentration. The obese mice were fed high-fat diets supplemented by 1, 3, and 5% of the onion peel extracts using 70% and 95% ethanol for 4 weeks. Body weight, feed intake, feed efficiency, small intestine weight, length, villi's length, and number of bacteria in intestine were determined. Body weight of mice fed 5% of onion extracts using both 70% and 95% ethanol was significantly lower than that of control (p<0.05). However, feed intake was increased in mice fed 5% of onion extracts at both fermented ethanol levels. Small intestine weight and length of mice showed no significant change with supplementation of the onion peel extracts. However, length of small intestine villi was significantly longer than that of control. Total bacteria counts of Cl. Perfringenes and E. coli in small intestine of the mice were significantly reduced by supplementation of 5% of onion extract using ethanol, while lactic acid bacteria were increased. These results suggest that 5% of onion peel extracts using ethanol at either 70% or 95% concentration have potential to be used as an additive for body weight control and enhanced gut health; however, more research on its effectiveness is needed.

• The Inventors News
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• no.23
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• pp.12-12
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• 2004

• 베이커리
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• no.2 s.439
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• pp.166-169
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• 2005

• Food Science of Animal Resources
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• v.20 no.2
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• pp.93-100
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• 2000

Effects of onion peel (OP) components (quercetin and rutin) in press ham on TBARS, pH, redness (a*) and flavor (panel test) were investigated during cold storage. TBARS in OP samples of high concentration was significantly (P〈0.05) lower than control during cold storage. This result suggests that OP components have an antioxidant activity in press ham. Also, redness of OP samples was significantly (P〈0.05) higher than control after three weeks of cold storage. Cured ham redness could be improved through lower pH of OP samples compared to that of control. However, flavor score of OP samples was not significantly (P〉0.05) different with control during cold storage. It could be possible that OP components plays role as an antioxidant without any negative effects on plavor of press ham.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.6
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• pp.854-858
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• 2014

Extracts of Styela clava (Korean name: miduduk) tunic, mulberry, and onion were selected by pre-screening to develop low-salt soy sauce (12% salt content) with anti-hypertensive activity. After choosing the formula for low-salt soy sauce, extracts were added separately or by mixture in combination. In the case of anti-hypertensive activity, low-salt soy sauce containing extracts of miduduk tunic and onion showed 30% increased inhibitory activity towards angiotensin I converting enzyme, compared to normal salt soy sauce (15% salt content). Addition of extracts also significantly increased DPPH radical scavenging activities of the soy sauces. These results suggest that natural resources such as miduduk tunic, mulberry, and/or onion might be potential candidates for development of low-salt soy sauce with anti-hypertensive activity.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.595-600
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• 1997

The antioxidant activity of the solvent fractions extracted from onion skin was examined. The antioxidant activity of methanol extract at the cencentration of 0.02% and 0.03% was stronger than that of mixed tocopherol. The antioxidant activity of the fractions of methanol extract increased in the order of butanol> ethyl acetate> ethyl ether> water fraction. The antioxidant activity of each fractions was strongly related with total phenol content and HDA. Further separation of butanol fraction by TLC yielded 6 fluorescent bands with Rf values of 0.20, 0.33, 0.49, 0.60 and 0.94. The total phenol content and HDA of fluorescent band, Rf 0.96, were remarkable higher than those of the other band and exhibited a strong UV absorption at 255 nm and 317 nm, which would be specifically produced by flavonol. Spectral analyses indicated that the major antioxidant component was quercetin aglycone (3,3',4',5,7-pentahydroxyflavone).

• 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.