• Food Science and Biotechnology
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• v.16 no.3
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• pp.421-425
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• 2007

The inhibitory effect of onion extract on polyphenol oxidase (PPO) and browning of peach juice was investigated. Various reducing agents such as L-ascorbic acid, L-cysteine, dithiothreitol, glutathione, and sodium pyrosulfite strongly inhibited polyphenol oxidase extracted from peach. The enzyme was also inhibited by addition of water extract of onion. Regardless of substrates used, the addition of heated onion extract exhibited stronger inhibitory effect on peach polyphenol oxidase activity than that of the fresh one. The inhibitory effect of onion extract was dependent on heating temperature and time. The onion extract inhibited the peach polyphenol oxidase non-competitively. The heating of onion extract in the presence of glucose, glycine stimulated the inhibitory effect of the onion extract, which suggests non-enzymatic browning products produced during heating might be responsible for the stronger inhibitory action of the heated onion extract. The retardation of peach juice browning by onion extract seems to be caused by inhibition of peach PPO.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.5
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• pp.870-874
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• 2000

This study was designed to investigate the cytotoxic effect of methanol extract of garlic, onion and those mixture on two kinds of human lung cancer cell lines (NCI-H522, NCI-H596) using MTT assay. MeOH extract of garlic, onion and those mixture showed cytotoxic effect on both NCI_H522 and NCI-H596. The growth of the cancer cells exposed to medium containing garlic, onion extracts and those mixture was inhibited dose-dependently. The growth of NCI-H522 was inhibited more in the garlic extract than in the onion extract, but that of HCI-H596 was inhibited highese in the onion extract. IC50 values of garlic extract on NCI-H522 and NCI-H596 were 0.84 mg/mL, 0.88 mg/mL and those of onion extract were 1.04 and 0.79, respectively. and the mixture of garlic and onion extracts also inhibited the growth of both NCI-H522 and NCI-H596 cells.

• Journal of the Korean Applied Science and Technology
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• v.16 no.2
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• pp.143-146
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• 1999

In order to study for Onion ethanolic extract on the Heavy Metal Elimination and antioxidation, the peroxide values of oil and eliminated metal were analyzed. The results are follows: It was very effective as a retardant for autoxidation processing of the soybean and olive oil by the Onion ethanolic extract. Quercetin in the Onion ethanolic extract was affected as a ligand for chelating with some metals. Through out this study, Quercetin in the Onion ethanolic extract was affected as eliminator of the Mercury, Lead, and Cadmium.Abstracts In order to study for Onion ethanolic extract on the Heavy Metal Elimination and antioxidation, the peroxide values of oil and eliminated metal were analyzed. The results are follows: It was very effective as a retardant for autoxidation processing of the soybean and olive oil by the Onion ethanolic extract. Quercetin in the Onion ethanolic extract was affected as a ligand for chelating with some metals. Through out this study, quercetin in the Onion ethanolic extract was affected as eliminator of the mercury, lead, and cadmium.

• Preventive Nutrition and Food Science
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• v.6 no.1
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• pp.16-18
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• 2001

The inhibitory effect of onion extract on mushroon tyrosinase activity was investigated. The enzyme activity was inhibited by 96.3% with th addition of onion extract. The inhibitor action of onion extract toward mushroom tyrosinase activity slightly increased after heat treatment at 10$0^{\circ}C$ for 10 mn (97.5%) and decreased after incubation of the extract at pH 2.3 for 3hrs (79.9%). However, the inhibitor action of the extract after dialysis decreased to18.8%. The onion extract showed drastic inhibition of the browning in mushroom.

• Nutrition Research and Practice
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• v.7 no.5
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• pp.373-379
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• 2013

The consumption of fruits and vegetables that have high polyphenol content has been previously associated with a reduced risk for cardiovascular disease. We investigated the effects of onion peel extract on plasma total antioxidant capacity, lipid peroxidation, and leukocyte DNA damage. This study was a randomized, double-blind, placebo-controlled, crossover trial. Healthy female subjects received either onion peel extract or placebo (dextrin) for two weeks, underwent a 1-week washout period, and then received the other treatment for an additional two weeks. After two weeks of onion peel extract supplementation, the total cholesterol level, low-density lipoprotein cholesterol level, and atherogenic index significantly decreased (P < 0.05). No changes were observed in activities of erythrocyte antioxidant enzymes or levels of lipid peroxidation markers following onion peel extract supplementation. Additionally, no significant difference was found in plasma antioxidant vitamin (retinol, tocopherols, carotenoids, and coenzyme Q10) levels or ex vivo $H_2O_2$-provoked oxidative DNA damage after onion peel extract supplementation. The present interventional study provides evidence of the health benefits of onion peel extract and demonstrates its effects in modulating lipid profiles in healthy young Korean women.

• Textile Coloration and Finishing
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• v.29 no.2
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• pp.62-68
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• 2017

Coffee sludge and onion shells are known typically as waste resources as well as simultaneously being the raw material for dye having a golden brown color. This research studies the dyeability, functionality, and colors of woolen fabric after being dyed by different dyeing method using coffee sludge and onion shells extract. The woolen fabric was refined and pre-mordanted with tannin. The dyeing process conducted was single-dye, using coffee sludge and onion shells extract, sequential multi-dye, consecutively dyeing with coffee sludge and onion shells, and mixed-dye, blending coffee sludge extract and onion shells extract to dye. The dyeing was measured on the surface color, color fastness, and UV-protection ability. As a result, the expression of various hues of tan using coffee sludge and onion shells extract were shown to be possible. Additionally, single-dye, sequential multi-dye, mixed-dye had generally superiority in color fastness to light, all rating 3 and color fastness to washing, rating 3 or 4, showing relatively stable color fastness to washing. The UV protection ability was shown to be better, especially appearing satisfactory in the UV-B protection, all measured to be over 90%.

• Korean Journal of Pharmacognosy
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• v.44 no.4
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• pp.391-396
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• 2013

In this study, we investigated the effects of onion(Allium cepa L.) peel extraction aplication on UVB-induced damage of mouse skin. The male C57BL/6 weeks mice were divided into three groups; the control group(Con), the UVB irradiated group(UVB) and the group treated with onion peel extract after UVB irradiation(UVB+Onion peel). Onion peel extraction were topically treated after UVB irradiation(800 $mJ/cm^2$) to dorsal skin. We were measured TEWL, melanin value, erythema index and histological of mouse skin. In the TEWL, melanin value and erythema index observation, UVB+onion peel group were decreased then in the UVB group and 120 and 168 hr groups were similar to the control group. In the histological observation, UVB+onion peel group were indicated hyperkeratosis then in the UVB. These results showed that onion peel extract as a topical application may have preventive effect against UVB-induced skin damage. Therefore onion peel extract might be good material for UVB-damage skin care.

• Korean Journal of Pharmacognosy
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• v.18 no.1
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• pp.34-40
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• 1987

Onion extracts were tested for effects on the growth and lactic acid production of Lactobacillus bulgaricus in the medium containing mercury. The media containing mercury were added with onion extracts and inoculated with the bacterium and then incubated at $39^{\circ}$ for four days. All of the onion extracts examined increased the growth and lactic acid production of the bacterium in the medium containing mercury. At the addition of the edible portion extract of onion to the medium containing 5 ppm, 10 ppm and 20 ppm mercury, the higher the concentration of the onion extract was added, the greater the increasing effect on the growth and lactic acid production. The brown peel extract of onion increased the growth and lactic acid production of the bacterium in the medium containing mercury at all concentrations. The higher the concentration of the extract added, the more effective the increasing effect. The onion solutions of edible portion and brown peel extracted at $90^{\circ}\;to\;100^{\circ}$ showed more desirable effects than those extracted at the room temperature. Among four kinds of the onion extracts, the brown peel solution extracted at $90^{\circ}\;to\;100^{\circ}$ was the most effective in increase of the growth and lactic acid production in the medium containing mercury.

• Food Science of Animal Resources
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• v.35 no.3
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• pp.277-285
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• 2015

This study was conducted to investigate the effects of kimchi powder and onion peel extract on the quality characteristics of emulsion sausage manufactured with irradiated pork. The emulsion sausages were formulated with 2% kimchi powder and/or 0.05% onion peel extract. The changes in pH value of all treatments were similar, depending on storage periods. The addition of kimchi powder increased the redness and yellowness of the emulsion sausage. The addition of onion peel extract decreased the thiobarbituric acid reactive substances value of the emulsion sausages prepared with irradiated pork. The volatile basic nitrogen value of the emulsion sausage prepared with kimchi powder was the highest, whereas that of the emulsion sausage prepared with onion peel extract was the lowest. The treatment without kimchi powder or onion peel extract and the treatments prepared with onion peel extract showed lower microbial populations than the other treatment. Sensory evaluations indicated that a higher acceptability was attained when kimchi powder was added to the emulsion sausages manufactured with irradiated pork. In conclusion, our results suggest that combined use of kimchi powder and onion peel extract could improve quality characteristics and shelf stability of the emulsion sausage formulated with irradiated pork during chilled storage.

• Korean Journal of Medicinal Crop Science
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• v.22 no.3
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• pp.203-209
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• 2014

Onion (Allium cepa L.) is one of the richest sources of flavonoids in human diet. Onion peel contains over 20 times more quercetin than onion flesh. In this study, we studied the effects of onion peel water extract (OPE) on the blood lipid profiles in mice. The onion peel extracts was extracted with hot water. The experimental groups were divided with 3 groups (n = 6) of ICR male mice: normal diet + distilled water (NC), high-fat diet + distilled water (HF), high-fat diet + onion peel water extract 20 mg/kg (OPE-20). The oral administration was conducted daily. The experimental period was 7 weeks. Onion peel water extract showed higher concentration of polyphenol gallic acid and anti-oxidant trolox equivalent than the ethanol extract. The body weight gain and food efficiency ratio was significantly lower in the OPE-20 group as compared with HF group (p < 0.05). The epididymal fat and retroperitoneal fat showed significantly lower weights and sizes in the OPE-20 group as compared with HF group (p < 0.05). The serum levels of total cholesterol, LDL cholesterol and triglyceride were significantly lower in the OPE-20 group as compared with HF group (p < 0.05). The OPE-20 group showed higher HDL cholesterol concentration than HF group (p < 0.05). Atherogenic index was ignificantly lower in as compared with HF group (p < 0.05). The serum levels of glucose, GOT and GPT were significantly lower in the OPE-20 group as compared with HF group (p < 0.05). In these results, we suggests that onion peel water extracts supplementation can reduces the serum lipid components and improves the lipid metabolism in hyperlipidemic mice induced with a high-fat diet.