• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.578-583
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• 2000

To use onion pomace produced from concentrated onion juice processing, dried onion pomace or dried onions were mixed with com grits at levels of 10, 20, and 30% and were extruded in a twin-screw extruder. Quality properties of extruded onion snack were investigated. Low-lignin dietary fiber of dried onion pomace was approximately 2 times higher than that of dried onion. Browning increased with increasing onion content. Reducing sugar and free sugar in onion snack showed high content by increasing onion concentration and the majority of free sugar consisted of glucose and fructose. Flavonoid in control snack was not detected and the flavonoid content containing quercetin and quercetin glycosides was about 50% less in onion pomace snack than in onion snack. Sensory evaluation of onion snack containing 10% concentration of dried onion pomace or dried onion indicated the products were acceptable in overall eating-quality.

• Journal of The Korean Society of Grassland and Forage Science
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• v.43 no.3
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• pp.138-147
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• 2023

Buckwheat (Fagopyrum esculentum), which is a traditional Korean crop, has been known as a health food due to its rich nutrition. This study was conducted to evaluate the change in flavonoid content of flowers and seeds during post-flowering growth of Korean tartary buckwheat variety 'Hwanggeummiso', with the aim of providing basic data for the development of functional food and feed additive. Tartary buckwheat took 69 and 99 days from the sowing date to reach the flowering and maturity stages, respectively. As a result of examining the flavonoid components of each part of tartary buckwheat, chlorogenic acid, rutin, and isoquercitrin of flowers increased from the flowering period on 22 May (0 days after flowering) to 42 days after flowering, while quercetin increased until 21 days after flowering and then decreased thereafter. In seeds, chlorogenic acid, rutin, and isoquercitrin were most abundant at the time of seed-bearing on 14 days after flowering, and showed a decreasing tendency thereafter. On the other hand, quercetin showed a tendency to increase until 21 days after flowering and then decrease. Overall, the flavonoid content was higher in flowers than in seeds, with rutin being particularly prominent. Based on this, the possibility as food materials and feed additives was confirmed using buckwheat produced in Korea.

• Journal of the Korean Dietetic Association
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• v.19 no.4
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• pp.389-399
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• 2013

This study compared the nutritional composition and antioxidative activity of different parts of Taraxacum coreanum (aerial parts and roots) according to different drying methods (natural drying and freeze-drying). There were no significant differences in vitamin C content in roots depending on the drying methods. However, vitamin A (P<0.01), E (P<0.001) and C (P<0.001) content of aerial parts, and vitamin A (P<0.001) and E (P<0.05) content of roots were significantly higher after freeze-drying compared to natural drying. For organic acids, the oxalic acid content of the aerial parts and roots were the highest. The total polyphenol and total flavonoid content in extracts from the aerial parts (P<0.01) and roots (P<0.05) were significantly higher after freeze-drying compared to natural drying. In addition, the total polyphenol and flavonoid content, DPPH radical scavenging activity, and antioxidative index from the natural drying and freeze-drying of Taraxacum coreanum extracts were significantly higher in the aerial parts compared to the roots (P<0.05). These results suggest that the nutritional composition and antioxidative activity of Taraxacum coreanum are higher in the aerial parts compared to the roots, and higher after freeze-drying compared to natural drying. Therefore, the aerial parts of Taraxacum coreanum could be suggested as an antioxidative functional food source.

• Journal of Digital Convergence
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• v.13 no.7
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• pp.431-436
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• 2015

To determine fusion-complex activity of Camellia extract extracted hot water, this study was conducted. Special catechin was identified at this extract by analysis of catechin. In analysis of antioxidant activity, the extract was contained antioxidant material and flower among the other parts showed high antioxidant activity. flavonoid showed most high content of Camellia. Flavonoid content was found to be $223.29{\pm}0.005mg/g$ to measured most high to stem, a control group was measured Green tea new leaves $126.14{\pm}0.005mg/g$. Total polyphenol content exhibited most high content at new leaves and flavonoid showed most high content at stem. ${\gamma}$-Amino butyric acid (GAVA) among the free amino acid showed highly at all parts.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.290-290
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• 2017

Rice (Oryza sativa L.) is one of the most consumed staple food crop which is energy source as carbohydrate and also is considered as the important antioxidant sources including various phenolic compounds. According to the increasing demand of healthy life, the concern to antioxidant also is increasing because of its health-promoting effect. Phenolic compounds are one of the plant secondary metabolites class, which shows various benefits to preventing or treating chronic diseases. In this study, we have measured the total phenol content from total 647 rice samples using the Floin-Ciocalteau method, and then were selected 30 rice genetic resources classified with high, middle, and low group on the basis of total phenol content. The average of the total phenol content of each group was high-group ($6892.9{\pm}488.5{\mu}g\;GAE/g$) > middle-group ($1428.1{\pm}76.0{\mu}g\;GAE/g$) > low-group ($97.6{\pm}11.4{\mu}g\;GAE/g$). The selected rice samples were analyzed with LC-MS/MS to find the composition and concentration of individual phenolic in rice grain. High-group and middle-group contained large amounts of protocatechuic acid and (+)-catechin whereas low-group showed limited amount. Among high-group samples, rice samples with black pericarp color (IT 174089, IT 220079, and IT 259958) had high content of peonidin-3-O-glucoside. Further, these black rice samples were special since polydatin, rarely found stilbenoid in rice grain, was detected. Overall, both the sum of phenolic acid and the sum of flavonoid were high-group > middle-group > low-group. Also, each group exhibited different phenolic compositions; high-group consisted of flavonoid more than phenolic acid, middle-group and low-group was comprised of phenolic acid rather than flavonoid, and non-pigmented rice was composed by fully phenolic acid. The total phenol content had positive relationships with the sum of phenolic compound (r = 0.64), the sum of flavonoid (r = 0.74) at the significance level of p < 0.0001. In addition, protocatechuic acid and quercetin showed positive correlation with above phenolic composition parameters; in order, r = 0.98, 0.65 for protocatechuic acid and r = 0.73, 0.78 for quercetin (p < 0.0001). In conclusion, the total phenol content assay showed the possibility of utilization as a phenolic composition indicator in rice grain. Also, this result was suggested study pigment on other material.

• Journal of Applied Biological Chemistry
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• v.63 no.1
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• pp.111-116
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• 2020

Total polyphenol contents, flavonoid contents, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activities of ethanol extracts of 20 herbal plants (sage, turmeric, mace, bayleaf, fenugreek, oregano, blackpepper, whitepepper, clove, marjoram, cinnamon, coriander, basil, dillseed, mustard, cadamon, thyme, celery, rosemary, cumin) were analyzed for the screening of high flavonoid-containing plant resource. Thyme extract, showing the highest flavonoid content and a high degree of antioxidant activity, was selected as a bioactive cosmetic material. The total polyphenols and flavonoids contents of thyme extracts were measured as 6.90 mg chlorogenic acid equivalent (CAE)/100 g and 1.71 mg naringin equivalent (NE)/100 g, respectively, and DPPH radical scavenging activities was 90%. Among the tested organic solvents, hexane gave the highest extraction yield. Thus hexane was selected as the most suitable solvent for the extraction of thyme. Response surface method was used to obtain optimized extraction conditions for thyme: reaction temperature of 35.9 ℃, raw material to hexane ratio of 1.63:25 (w/v), and reaction time of 192 min. These predicted extraction conditions was validated by a total flavonoid extraction experiment showing a value equivalent to 96.3% of the predicted total flavonoid content. It is expected that the optimized solvent extraction conditions could be used for the production of flavonoid using thyme.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.1
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• pp.15-21
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• 2003

Quantification of functional components, such as ［l -deoxynojirimycin (DNJ), ${\gamma}$-aminobutyric acid (GABA) and flavonoids］ of four different cultivars (YK-209, Cheongil, Yongchon and Kaeryang) and parts (upper, middle and lower) of mulberry leaves harvested in different areas and periods was performed by HPLC to select the best Quality of mulberry leaf suitable for manufacture of functional foods. Among four mulberry cultivars, YK-209 mulberry leaf had the highest DNJ, GABA and flavonoids levels. YK-209 mulberry leaf harvested in "Yeongcheon" area had greater DNJ, GABA and flavonoid contents than those harvested in "Sangju" area. Four major flavonoids of mulberry leaf were rutin, isoquercitrin, kaempferol-3-Ο-rutinoside, astragalin, and their levels varied greatly with cultivars. YK-BO9 mulberry leaf had the highest flavonoids content among four cultivars. DNJ, GABA and flavonoid contents of young YK-209 mulberry leaf were relatively higher in the upper part than those in the middle and lower parts. Additionally, levels of DNJ, GABA and flavonoids were higher in mulberry leaves harvested in the eariler growing season (May) than in the late growing seasons (June and August) . Particularly, among four flavonoids, rutin content had the highest in the mulberry leaf harvested in May, while isoquercitrin content did the highest in the mulberry leaf harvested in June and August. These results suggest that YK-209 mulberry leaf having high amount of functional components, such as DNJ, GABA and flavonoids, may be useful as potential source of beverages and tablets.verages and tablets.

• Archives of Pharmacal Research
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• v.27 no.11
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• pp.1114-1119
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• 2004

This paper describes the quantitative determination of flavonoids, tannins and ellagic acid in the leaves from wild and cultivated variations of Rubus L. species (Rosaceae): raspberry (2 wild and 13 cultivars) and blackberry (3 wild and 3 cultivars). The content of flavonoids was analyzed using spectrophotometric (the Christ-M llers method) and HPLC analysis after acid hydrolysis. The content of tannins was determined by the weight method, with hide powder, described by German Pharmacopoeia 10 (DAB 10). Ellagic acid content was examined using the HPLC method after acid hydrolysis. Flavonoid content, determined using the Christ-Muller's method was higher for the blackberry leaves than for the raspberry leaves and varied between 0.46% and 1.05%. Quercetin and kaempferol were predominant in all samples analyzed using the HPLC method. The highest flavonoid content was found in the leaves of R. nessensis (1.06%); with results in all of the examined samples varying between 0.27% and 1.06%. The concentration of ellagic acid in all species was determined after acid hydrolysis and ranged from 2.06% to 6.89%. The leaves of raspberries are characterized by greater amounts of tannins (varying between 2.62% and 6.87%) than the leaves of other species. The results from this study indicate that the analyzed species are a rich source of flavonoids, ellagic acid and tannins, which may be used for the quality assessment of Rubus L. species leaves.

• Journal of Environmental Science International
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• v.25 no.5
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• pp.695-703
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• 2016

The purpose of this study was to measure the bioactivity and antioxidant activity of Orostachys japonicus A. Berger. Orostachys japonicus A. Berger have been known to contain functional materials such as kaempferol, hydroquinone, methyl gallate, quercetin, gallic acid etc. To identify the main functional materials of Orostachys japonicus A. Berger, the contents of flavonoid and phenol were measured. We extracted Orostachys japonicus A. Berger powder from four solvents such as chloroform:methanol (CM, 2:1, v/v), distilled water (DW), 70% methanol, 70% ethanol. After that, this study determined tannin, total phenol, flavonoid content, DPPH radical scavenging activity, ABTS radical scavenging activity, ferric reducing antioxidant power and reducing power of Orostachys japonicus A. Berger extracts and as results of comparing each extract. respectively. From the above results shows that antioxidant activity and bioactivity of Orostachys japonicus A. Berger extracts was higher in the order of 70% ethanol, 70% methanol, DW and CM (p<0.05). The results showed that antioxidant activity of Orostachys japonicus A. Berger extracts supposed to affect by the total phenol and flavonoid contents.

• Journal of agriculture & life science
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• v.51 no.2
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• pp.47-59
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• 2017

The objectives of this study were to select the seeds of Cucurbitaceae and Solanaceae genotypes in terms of superior with bioactive compounds content and to inform sophisticated data for developing the high value-added products. We evaluated to aspects of the antioxidant activity, polyphenol content, and flavonoid contents in seeds from two vegetable family. We used in the Cucurbitaceae(watermelon, squash, bitter gourd, and sponge gourd) and Solanaceae(hot pepper, sweet pepper, and egg plant) the total 408 genotypes. In Cucurbitaceae, polyphenol content of watermelon and squash genotypes were ranged 19.9-343.8 and $6.1-81.2mg{\cdot}100g^{-1}\;DW$, respectively. The polyphenol content of watermelon genotypes was 12% among all genotypes over $160mg{\cdot}100g^{-1}\;DW$. The mean of flavonoid content in watermelon and squash genotypes represented 80 and $41.3mg{\cdot}100g^{-1}\;DW$, respectively. In Solanaceae, flavonoid content of hot pepper genotypes was ranged $64.4-472.5mg{\cdot}100g^{-1}\;DW$, with an average of $165.0mg{\cdot}100g^{-1}$. The 23 hot pepper genotypes were classified over 90% antioxidant activity. The antioxidant activity of sweet pepper was ranged 35.9-90.3%, and 23% of all genotypes represented 82% antioxidant activity. The polyphenol and flavonoid content of egg plant was ranged $38.1-642.0mg{\cdot}100g^{-1}\;DW$ and $14.2-1217.0mg{\cdot}100g^{-1}\;DW$, respectively. In addition, we selected that 8 egg plant with the superior genotypes for antioxidant activity, polyphenol, and flavonoid content. Results revealed that there was significant variation of antioxidant activity and bioactive compounds contents in both vegetable famaily. In addition, we suggested that selected genotypes seeds with high contain bioactive compounds will be more efficiency to develop natural value-added products.