• 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.

• Korean Journal of Breeding Science
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• v.43 no.2
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• pp.126-132
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• 2011

The bulb storability of eight red and ten yellow onion (Allium cepa L.) cultivars grown primarily in Korea was evaluated. During storage, sprouting occurred earlier in red cultivars than in yellow cultivars. In addition, the ratio of sprouted to unsprouted bulbs increased more rapidly in red cultivars than in yellow cultivars. However, not all yellow cultivars had strong storabilities. Bulb storability of three yellow cultivars was as poor as that of red cultivars, suggesting only a slight possibility of a pleiotropic effect of color and bulb storability. Meanwhile, $F_3$ lines of a red cultivar selected based on stronger storabilities showed intermediate storabilities between those of the red and yellow cultivars, implying that strong storability could be obtained by successive selection. In contrast, $F_1$ hybrids from crosses between yellow and red breeding lines showed poor storability compared with the yellow cultivars, indicating that poor storability may be dominant over strong storability. The relationships between color and other traits that potentially affect storability, such as fresh and dry weight, water content, and firmness of bulbs, were evaluated. No significant differences in these traits were observed between the two colors, although the water content of yellow cultivars and the dry weight of red cultivars were slightly higher than their counterparts. Correlation analyses between bulb storability and other traits, including weight, water content, and firmness, also showed no significant correlations. In this study, no correlations were identified between bulb color, storability, and other traits. However, based on these results, red cultivars with stronger storabilities could be developed through successive selection of bulbs with stronger storabilities.

• Horticultural Science & Technology
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• v.31 no.1
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• pp.72-79
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• 2013

Inactivation of the gene coding for dihydroflavonol 4-reductase (DFR) is responsible for the color difference between red and yellow onions (Allium cepa L.). Two inactive DFR-A alleles, DFR-$A^{PS}$ and DFR-$A^{DEL}$, were identified in our previous study. A functional marker was developed on the basis of the premature stop codon that inactivated the DFR-$A^{PS}$ allele. A derived cleaved amplified polymorphic sequences (dCAPS) primer was designed to detect the single nucleotide polymorphism, an A/T transition, which produced the premature stop codon. Digested PCR products clearly distinguished the homozygous and heterozygous red $F_2$ individuals. Meanwhile, to develop a molecular marker for detection of the DFR-$A^{DEL}$ allele in which entire DFR-A gene was deleted, genome walking was performed and approximately 3 kb 5' and 3' flanking sequences of the DFR-$A^R$ coding region were obtained. PCR amplification using multiple primers binding to the extended flanking regions showed that more of the extended region of the DFR-A gene was deleted in the DFR-$A^{DEL}$ allele. A dominant simple PCR marker was developed to identify the DFR-$A^{DEL}$ allele using the dissimilar 3' flanking sequences of the DFR-A gene and homologous DFR-B pseudogene. Distribution of the DFR-$A^{PS}$ and DFR-$A^{DEL}$ alleles in yellow onion cultivars bred in Korea and Japan was surveyed using molecular makers developed in this study. Results showed predominant existence of the DFR-$A^{PS}$ allele in yellow onion cultivars.

• Korean Journal of Food Science and Technology
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• v.53 no.4
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• pp.434-445
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• 2021

The content of major constituents and antioxidant activities of nine onion cultivars, namely yellow domestic cultivars Meapsihwang, Sinsunhwang, Yeonsinhwang, Yeongbohwang, and Yeongpoonghwang, red domestic cultivar Eumjinara, green domestic cultivar Sweetgreen, yellow-introduced cultivar Sunpower, and red-introduced cultivar Cheonjujeok, were compared. Yeongbohwang and Cheonjujeok had the highest total phenolic and total flavonoid contents among the six yellow and two red cultivars, respectively. The red cultivars displayed the highest DPPH and ABTS⁺ radical scavenging activities (DRSAs and ARSAs, respectively) and reducing power (RP). Among all cultivars, Cheonjujeok and Eumjinara had the highest DRSA, while both red cultivars had similar ARSAs. Among the yellow cultivars, Sinsunhwang and Yeongbohwang showed excellent DRSAs. The RP of the domestic cultivars was slightly higher than that of the introduced cultivars. Thus, the domestic cultivar Yeongbohwang exhibited excellent characteristics among the yellow cultivars, while the red cultivars Eumjinara and Cheonjujeok were similar.

• 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.

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.5
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• pp.657-664
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• 2012

The aim of this study is to investigate the effects of onion vinegar on the cerebral blood flow by measuring the changes of regional cerebral blood flow (rCBF) and mean arterial blood pressure (MABP) and by observing the recovery of focal ischemic brain injury in rats. Rats are divided into thee groups depending on the medication; control group (no medication), 8.8-OV group (vinegar using 8.8 brix onion medication), 14.6-OV group (vinegar using 14.6 brix onion medication). The medication of onion vinegar significantly increased rCBF but decreased MABP. This result suggests that onion vinegar significantly increased rCBF by dilating arterial diameter. In addition, focal ischemic brain injury is induced in rats by middle cerebral arterial occlusion. The recovery from focal ischemic brain injury is more significantly improved in the groups using onion vinegar compared to the control group. The amount of recovery is measured by the GAP-43 and the medication of onion vinegar significantly increased GAP-43. This result suggests that onion vinegar is effective on the nerve regeneration. After the medication, the change of body weight, outcomes of renal and liver function test, and outcomes of CBC are analysed for safety examination. There are no statistical differences among control group and all experimental groups in the body weight, renal and liver function test, and CBC. In conclusion, these results suggest that onion vinegar can increase rCBF in normal state, and improve the stability of rCBF in ischemic state.

• 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)

• Horticultural Science & Technology
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• v.28 no.6
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• pp.921-927
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• 2010

The objective of this study was to improve the breeding efficiency and consumption of red onion by analysis of chemical components. The red cultivar S&P5294 ($52.9mg{\cdot}g^{-1}$ F.W.) resulted in the highest sugar content, and sweetness whereas 'Redprime' had the lowest. For the pyruvic acid content the cultivar 'Redsun' showed the highest value, followed by 'Sunpower' (yellow onion) and S&P7270. Breeding lines had higher sugar content and sweetness than 'Redprime' and 'Sunpower', while they had less pyruvic acid value than 'Redsun' and 'Sunpower'. The the same trend was verified for the total phenol and total flavonoid, of which breeding lines were found to have more content than 'Redprime' or 'Sunpower'. Three major flavonoids, rutin (quercetin glycoside), myricetin, and quercetin, were identified and quantified whereas kaempferol was not detected in all cultivars. Rutin was the major flavonoid present in all cultivars (136.9 to $169.9{\mu}g{\cdot}g^{-1}$ F.W.), followed by quercetin (62.5 to $135.7{\mu}g{\cdot}g^{-1}$ F.W.). Relatively smaller amount of myricetin (11.2 to $16.1{\mu}g{\cdot}g^{-1}$ F.W.) was also detected. Among nine cultivars, 'Redsun' exhibited significantly ($p$ < 0.05) higher content of quercetin and rutin (135.7 and $169.9{\mu}g{\cdot}g^{-1}$ F.W., respectively), and S&P5296 had the highest content of myricetin($16.1{\mu}g{\cdot}g^{-1}$ F.W.). Breeding lines had more quercetin, rutin and myricetin contents than the cultivars 'Redprime' and 'Sunpower'. Hampyeong had the highest content for total phenol and total flavonoid, followed by Andong and Changyeong whereas Changyeong had the highest value for rutin, myricetin and quercetin followed by Hampyeong and Andong. Among red onion cultivars, 'Redsun' showed the highest value for anthocyanin, followed by S&P5295 and S&P5296, which the cultivar 'Redprime' had significantly (p<0.05) lower content(35.5 mg%).