• Korean Journal of Food Science and Technology
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• v.54 no.2
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• pp.115-125
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• 2022

Flavonoids are bioactive plant metabolites that have a range of beneficial effects on human health. Quercetin 4'-glycoside (Q4'G), quercetin 3,4'-diglycoside (Q3,4'G), and quercetin aglycone (QA) are the main flavonoids found in onions. QA, in particular, is likely to have a greater biological effect than glycosides. To develop an onion extract with high quercetin content, the optimal extraction conditions for red onion powder containing the outer layer of the onion were determined. The effects of acid treatment on the concentration of quercetin glycosides and QA were evaluated. The flavonoids of red onion powder were optimally extracted under 60-70% ethanol at 70℃ for 2 h. The deglycosylation of Q3,4'G and an increase in Q4'G content occurred within 6 h of 0.2% acetic acid treatment. The QA content and deglycosylation of Q4'G eventually peaked at 24 h. In addition, QA content and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity were highly correlated, with a correlation coefficient of 0.90.

• Applied Biological Chemistry
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• v.38 no.5
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• pp.408-413
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• 1995

Investigations of the effects of pickle product ingredients on lipoxygenase (LOX) and methemoglobin (MHG, a nonenzymatic oxidant) catalyzing oxidation of linolenic acid were conducted. In addition, activities of LOX, peroxidase (POD) and catalase (CAT) in dry spices used in pickle products were determined. Some commercial pickle brines were observed to inhibit oxidation of linolenic acid by LOX and MHG. The ingredients in pickle products, such as dill oil emulsion, onion concentrate, oil cassia, polysorbate 80 and turmeric acid, reduced LOX and MHG catalyzed oxidation. Lipoxygenase activity was present in garlic, mustard seed and red pepper. Only in mustard seed, peroxidase activity was observed. Catalase activity was observed in garlic, black pepper, allspice and red pepper.

• Journal of Nutrition and Health
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• v.34 no.5
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• pp.513-524
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• 2001

This study was performed to investigate the effects of dry powders, ethanol extracts and juices of radish and onion on lipid metabolism, lipid peroxidation and antioxidative enzyme activity in rats. Forty-nine male Sprague-Dawley rats weighing 157$\pm$6g were blocked into seven groups according to body weight and raised for four weeks with diets containing 5%(w/w) dry powders of two different vegetables consumed frequently by Korean-radish(Raphanus sativus L.) and onion(Allium cepa L.), ethanol extracts and juices from equal amount of each dry powder. All the powders, ethanol extracts and juices of radish and onion decreased total lipids, triglycerides and total cholesterol concentrations in plasma and liver. Above all, onion ethanol extract decreased them most remarkably. It was thought that organosulfur compounds and flavonoids extracted from onion by ethanol inhibited biosynthesis and absorption of lipid and promoted degradation of lipid. Radish powder also decreased them by increasing fecal excretions of total lipids, triglycerides and total cholesterol most effectively. Catalase and glutathine peroxidase(GSH-px) activities in red blood cell(RBC) were most remarkably increased by radish powder and onion powder respectively. Superoxide dismutase(SOD), catalase and GSH-px activities in liver were most remarkably increased by onion ethanol extract, radish powder and onion ethanol extract respectively. Xanthine oxidase(XOD) activities in liver were most effectively decreased by ethanol extracts of radish and onion. Thiobarbituric acid reactive substance (TBARS) levels in plasma and liver of experimental groups were significantly lower than those of controls. Above all, onion powder decreased them most effectively. It was thought that vitamin E and high flavonoids in onion powder inhibited lipid peroxidation, promoting liver and RBC SOD, catalase and GSH-px activities and inhibiting XOD activities effectively. Flavonoids in onion ethanol extract inhibited lipid peroxidation, promoting three antioxident enzyme activities and inhibiting XOD activities most remarkably. Also flavonoids and high vitamin C in radish powder inhibited lipid peroxidation, promoting liver and RBC catalase most remarkably and inhibiting XOD activities. In conclusion, radish and onion were effective in lowering lipid levels and inhibiting of lipid peroxidation in animal tissue. From these data, radish and onion can be recommended in the treatment and prevention of diseases such as cardiovascular disease and cancer and in delaying aging. As ethanol from onion were most effective in lowering lipid level and promoting three antioxident enzymes, and inhibited lipid peroxidation as did we should try to utilize onion skin which is discarded though reported to have abundant flavonoids. (Korean J Nutrition 34(5) : 513~524, 2001)

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.4
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• pp.596-602
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• 2011

The aim of this study is to investigate the effects of onion and acanthopanax senticosus on body weight change, serum total cholesterol, HDL cholesterol, LDL cholesterol, triglyceride, free fatty acid, total lipid, phospholipid level, renal and liver function test, and CBC in obese rats and mice. Obese rats induced by high-fat fed are medicated for 7 weeks. Rats are divided into four groups depending on the medication; normal group (general-fat fed and no-medication), control group (high-fat fed and no medication), sample A group (high-fat fed and onion 100% extracted medication), sample B group (high-fat fed and onion 50% & acanthopanax senticosus 50% extracted medication), sample C group (high-fat fed and red onion 50% & acanthopanax senticosus 50% extracted medication). After medication, obesity related index, renal and liver function test, and CBC are analysed. There are significant statistical differences among control group and all experimental groups for the body weight change. There are significant statistical differences among control groups and all experimental groups for the total cholesterol, HDL cholesterol, LDL cholesterol, triglyceride level, free fatty acid, and phospholipid level. These results suggest that medications of onion and acanthopanax senticosus extracted products are effective for the treatment of obesity. Especially, onion 100% extracted product is more effective than the others.

• Korean Journal of Organic Agriculture
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• v.20 no.2
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• pp.201-209
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• 2012

This study was conducted to evaluate the effects of crop rotation on the weed occurrence in green onion and red pepper cultivation. Rye and hairy vetch were annually seeded for winter season. The reduction of weed germination was pronounced by about 50% in green onion field, but was not significant in red pepper field through rye cropping. Among weed species, the germination of Abutilon theophrasti, Cyperus iria and Digitaria ciliaris was distinctly inhibited by exudate of rye root, but not by that of hairy vetch in vitro experiment. The return of rye biomass into onion field decreased amount of weed biomass but increased index of weed diversity.

• Korean journal of food and cookery science
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• v.10 no.1
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• pp.35-38
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• 1994

The growth extent of Leu. mesenteroides and Lac. plantarum in the medium which contain sterilized extract of each of garlic, red pepper powder, and onion was examined. Garlic and onion decreased the growth of Leu. mesenteroides and Lac. Plantarum, and garlic represented more negative effect on the growth of Lac. plantarum than that of onion. Red pepper powder had negative effect on the growth of Lac. plantarum, and positive effect on the growth of Leu. mesenteroides in accordance with incubation processing.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.3
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• pp.393-400
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• 2010

This study examines the mordanting effect and multi functional properties of silk fabrics dyed with onion shell extracts that were mordanted with gallnut. The contents of this study are as follows. First, the optimum dyeing conditions were investigated by measuring the K/S value that depended the on dyeing conditions when silk fabrics were dyed with onion shell extracts. Second, the color, brightness, and chroma differences that appear after mordanting with gallnut were investigated by measuring the K/S and Munsell value. Third, the color fastness and antimicrobial activity were measured. When silk fabrics were dyed with onion shell extracts, the optimum dyeing conditions were a dyeing temperature of $70^{\circ}C$, a dyeing concentration of 160%, and a dyeing of time 30min. After mordanting with gallnut extracts, the K/S value increased remarkably and was larger in pre-mordanting than post-mordanting. The H value displayed yellow-red in all cases of pre and post mordanting. However, the H value was more reddish in the order of non-mordanting

• Journal of Environmental Health Sciences
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• v.31 no.1
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• pp.79-85
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• 2005

This study was undertaken to investigate the changes of index microorganisms and lactic acid bacteria of traditional Korean fermented vegetables (kimchi) during the ripening and fermentation period. A type of kimchi, baechoo-kimchi, was prepared and stored at $10^{\circ}C$ for 8 days. The numbers of the total aerobic bacteria, psychrotrophilic bacteria, coliform bacteria, and Escherichia coli in the kimchi and also in raw materials of the kimchi (Chinese cabbage, green onion, ginger, garlic, and red pepper) were counted using appropriate media. The highest number of aerobic bacteria was detected from ginger, then red pepper, then garlic, then Chinese cabbage, and lowest number from green onion. The highest number of psychrotrophilic bacteria was detected from red pepper, then Chinese cabbage, then garlic, then ginger, and the lowest number from green onion. Coliforms and E. coli were not detected from all of the raw materials of kimchi. Total aerobic bacteria and lactic acid bacteria of the kimchi showed gradually increasing during ripening and fermentation. The number of psychrotrophilic bacteria showed a similar level in the kimchi. Coliform bacteria were detected at the 3rd, 4th, and 5th day of the kimchi fermentation period, although they were not detected from the raw materials of the kimchi. However, the bacteria were not detected in the kimchi after 6 days. E. coli was not detected in all kimchi samples. The pH value of the kimchi gradually decreased, and acidity increased over fermentation period. This study indicates that there was contamination of coliform bacteria during the process of kimchi preparation, and lactic acid bacteria proliferated in the kimchi during fermentation inhibited the growth of coliforms. More research is needed to evaluate the inhibitory effects of each raw materials of kimchi.

• Korean Journal of Plant Resources
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• v.17 no.3
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• pp.219-226
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• 2004

Transplantings of onion (Allium cepa L.) seedlings are required for higher germinability and uniformity. This study was done to determine effects of various seed treatments (seed cleaning, priming, GA$_3$, prechilling, drying, and light quality during seed drying) on germination and seedling emergence. Nongwoodaego and Changnyungdaego were used as cultivars for checking seed germination, and two cultivars and Cheonjuguhyeonghwang were investigated with seedling production rate. Seed cleaning using water prior to the other treatments greatly increased germination rate. Priming with 200mM Ca(NO$_3$)$_2$ solution somewhat alleviated the germination rate while GA$_3$ did not. Prechilling had the highest rate among the treatments. Seed drying after prechilling enhanced the rate compared to non drying, and during drying the prechilled seeds red light illumination showed the greatest rate in comparison with dark, blue, and far-red ones. Seedling production rate was enhanced in sequential treatments of seed cleaning, prechilling for 3 to 5 days, and red light treatment during 6 hour seed drying.

• Horticulture, Environment, and Biotechnology : HEB
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• v.59 no.6
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• pp.919-927
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• 2018

To compare the antioxidant properties and flavonols in various parts; dry skin (DS) and edible portion (EP), of 8 red onions (Allium cepa L, ROs), total content of phenolics (TPC), flavonoids (TFC), and anthocyanins (TAC) and DPPH radical scavenging properties were estimated and the content of six flavonols were quantified by HPLC-PDA analysis. The major component of DS and EP of RO was quercetin and quercetin-4'-glucoside, respectively. Score plots of the PCA and PLS-DA were segregated by flavonols content and antioxidant properties according to the EP and DS of ROs. Loading plot of the PCA showed that the quercetin and sum of flavonol content were highly correlated with antioxidant activity of ROs. Therefore, flavonol content and antioxidant activity can be used as markers for distinct parts of ROs.