• Food Engineering Progress
• /
• v.21 no.3
• /
• pp.256-266
• /
• 2017

This study was designed to optimize ethanol extraction process of unfertilized corn silk (UCS) to maximize phytochemical contents and bioactivities. The response surface methodology (RSM) with central composite design (CCD) was employed to obtain the optimal extraction conditions. The influence of ethanol concentration, extraction temperature and extraction time on total polyphenol contents, total flavonoid contents, maysin contents, 2,2-diphenyl-1-picrylhydrazyl(DPPH) radical scavenging activities and tyrosinase inhibition were analyzed. For all dependable variables, the most significant factor was ethanol concentration followed by extraction temperature and extraction time. The following optimum conditions were determined by simultaneous optimization of several responses with the Derringer's desirability function using the numerical optimization function of the Design-Expert program: ethanol concentration 80.45%, extraction temperature $53.49^{\circ}C$, and extraction time 4.95 h. Under these conditions, the predicted values of total polyphenol contents, total flavonoid contents, maysin contents, DPPH radical scavenging activity and tyrosinase inhibition were $2758.74{\mu}g\;GAE/g$ dried sample, $1520.81{\mu}g\;QUE/g$ dried sample, 810.26 mg/100g dried sample, 56.86% and 43.49%, respectively, and the overall desirability (D) was 0.74.

• Korean Journal of Plant Resources
• /
• v.9 no.3
• /
• pp.224-229
• /
• 1996

Floral flavonoids of Hibiscus syriacus L. six complex with 68 formac all in all were examined. Thirteen flavonoids appeared on the two dimensional chromatogtams. Spot 5, however, occupied more than 50% in total flavonoid contents, and other spots were invariably minor pigments in all samples examined. Ten spots among 13 spots showed the characteristics of flavones, having color of purple to dark purple under UV light and yellow under ammonia gas, while spots reagents suggests that 10 purple spots are 4', 5-OH aglycone type. Four spots out of 10 purple spots were possible to be identified: spot 5, saponarin, spot 7, vitexin, spot 9, xylovitexin, and spot 11, rhamnosylvitexin, respectively. It was suggested that spot 13 might be apigenin-7-O-diglycoside.

• Korean Journal of Environmental Agriculture
• /
• v.36 no.1
• /
• pp.7-16
• /
• 2017

BACKGROUND: Increased value added by rapeseed (Brassica napus) by-product and the development of a usable rapeseed functional tea. METHODS AND RESULTS: To develop a usable rapeseed functional tea, the total flavonoid content in the varieties Youngsan, Tammi, Tamra, Naehan, Hanra, Mokpo No. 68, and Mokpo No. 111 was investigated. Effect of three treatments, i.e., drying, leaching, and roasting, on flavonoid contents or flower was tested using multiple processing methods per treatment. Total flavonoid content decreased under the various drying methods, confirming that flavonoid content is heat-dependent. This finding was more pronounced for freezing and oven-drying (15.3 and 13.8 mg/g DW, respectively), with a 10% difference in the total flavonoid content between the two methods. Under leaching conditions, the flavonoid content decreased with increasing treatment time. Notably, roasting methods did not result in loss of flavonoid content. The total flavonoid content in the rapeseed varieties decreased in the following order: Youngsan, Tammi, Tamra, Naehan, Hanra, Mokpo No. 68, and Mokpo No. 111. CONCLUSION: The flavonoid content in rapeseed flower was higher in Youngsan than in the other varieties, under processing conditions such as freeze-drying, leaching at $90^{\circ}C$ for 5 min, and roasting.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.41 no.6
• /
• pp.739-744
• /
• 2012

Cirsium japonicum (Gyonggido (GG), Gangwondo (GW), Jeollanamdo (JN) and Jejudo (JJ)) were investigated for their antioxidative components (total polyphenol and flavonoid contents) and their antioxidant activities (2,2-diphenyl-1-picrylhydrazyl) (DPPH), 2,2'-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS), ferric reducing antioxidant power (FRAP) and reducing power). Analysis of antioxidative components and activities showed significant (p<0.05) differences across samples from various regions (GG, GW, JN, JJ). Amounts of total polyphenol and flavonoid contents were in the order of GG${\geq}$GW>JJ>JN (p<0.05). The results of the antioxidative activity test of Cirsium japonicum showed that GG and GW had higher activities compared to others (p<0.05). Therefore, the results of the antioxidative activity test (DPPH, ABTS, FRAP and reducing power) were correlated with total polyphenol and flavonoid contents values.

• Preventive Nutrition and Food Science
• /
• v.21 no.2
• /
• pp.110-116
• /
• 2016

This study was performed to evaluate and compare the antioxidant substance content and antioxidant activities of white (Superior) and colored (Hongyoung, Jayoung, Jasim, Seohong, and Jaseo) potatoes. The potatoes were extracted with 80% ethanol and were evaluated for the total polyphenol, flavonoid, and anthocyanin contents and for 1,1-diphenyl-2-picrylhydrazyl (DPPH)/2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity, reducing power, and ferrous metal ion chelating effect. The total polyphenol, flavonoid, and anthocyanin contents of Hongyoung and Jayoung were higher than white and other colored potatoes. All colored potato extracts, except for Jaseo and Seohong, showed higher ABTS radical scavenging activities than the general white potato extract. Hongyoung and Jayoung had the highest ABTS and DPPH radical scavenging activities. Optical density values for the reducing power of Jayoung and Jaseo at concentration of 2 mg/mL were 0.148 and 0.090, respectively. All colored potato extracts had lower ferrous metal ion chelating effect than the white potato. A significant (P<0.05) positive correlation was observed between total polyphenol content and total flavonoid content (r=0.919), anthocyanin content (r=0.992), and ABTS radical scavenging activity (r=0.897). Based on these results, this research may be useful in developing the Hongyoung and Jayoung cultivars with high antioxidant activities.

• Korean Journal of Medicinal Crop Science
• /
• v.9 no.4
• /
• pp.290-294
• /
• 2001

Sambaekcho wines were fermented with 5% improved Nuruk, 120% brewing water, and powdered leaf or root as an additive, then the contents of several important phenolics were examined. As the fermentation progressed, the contents of total and flavonoid phenolics, and quercetin-related substances of the Sambaekcho wines increased continuously. The contents of the functional components of the Sambaekcho wines with powdered leaf were much higher than those of the Sambaekcho wines with powdered root, indicating leaf was more adequate than root in making Sambaekcho wine.

• Journal of the Korean Society of Food Culture
• /
• v.27 no.5
• /
• pp.505-511
• /
• 2012

This study was conducted to investigate the antioxidant activity of Jeolpyeon containing lotus seed powder. Original Jeolpyeon and Jeolpyeon with BHT (butyl hydroxy toluene) werecompared. Antioxidant activities were measured based ontotal polyphenolic contents, total flavonoid contents, DPPH radicalscavenging activity, reducing power, and SOD-like activity. Total polyphenolic and total flavonoid contents of Jeolpyeon containing lotus seed powder were estimated at $37.81{\pm}0.45$ mg GAE/g and $26.35{\pm}0.13$ mg QE/g respectively. DPPH radical scavenging activity increased upon addition of lotus seed powder. Further, reducing power was higher in Jeolpyeon containing lotus seed powder than original Jeolpyeon or Jeolpyeon with BHT. The antioxidative effect of Jeolpyeon significantly increased uponaddition of lotus seed powder.

• The Korean Journal of Food And Nutrition
• /
• v.34 no.2
• /
• pp.181-186
• /
• 2021

Antioxidant properties and antioxidant activities were analyzed for water extracts and 50% and 70% ethanol extracts of the leaf of Angelica gigas Nakai. The polyphenol and flavonoid contents in water, 50%, and 70% ethanol extract of the leaf of Angelica gigas Nakai, it was found that the polyphenol contents were 18.75 mg GAE/g, 28.95 mg GAE/g, and 34.73 mg GAE/g, respectively, and flavonoid contents were respectively. The DPPH IC50 scavenging activity was 45.84 mg/mL, 36.44 mg/mL, 19.11 mg/mL, respectively, and theABTS+ radical scavenging ability (1 mg/mL) was 28.73%, 22.79%, and 12.70%, respectively. Tyrosinase inhibitory activity, 70% ethanol extract, 50% ethanol extract, and water extract 33.14%, and 4.53%, respectively. Nitrite scavenging activity, 70% ethanol extract, 50% ethanol extract, and water extract were in the order of 1 mg/mL scavenging activity, 36.43%, 34.80%, and 18.85%, respectively.

• Korean journal of food and cookery science
• /
• v.29 no.6
• /
• pp.777-784
• /
• 2013

With the development of economy and culture, Korean traditional rice wine, Makgeolli, has been widely consumed with increasing popularity in Korea, China and other Asian countries. In this study, we examined the quality characteristics of red bean Makgeolli: pH, total acidity, alcohol contents, sugar contents, reducing sugar, color, total flavonoid contents, DPPH, microbial properties, sensory evaluation of Makgeolli added with red bean (0, 5, 10 and 15% by rice weight) during fermentation for 7 days. There were no significant differences between samples in acidity, alcohol contents, reducing sugars and yeat cell counts, but total flavonoid contents increased with increasing ratio of red bean(p<0.05). Makgeolli added with 10% red bean showed the highest antioxidation activity, and was not significantly different with Makgeolli without red bean in flavor, sweetness, sourness, bitterness and overall acceptance in sensory evaluation. Therefore, Makgeolli added with 10% red bean was considered to be the most suitable for the manufacturing.

• Korean Journal of Microbiology
• /
• v.48 no.1
• /
• pp.29-36
• /
• 2012

This study was conducted to investigate antioxidative and physiological activities of two stage fermented Chinese Yam (TSFCY) by Monascus sp. MK2 and Lactobacillus brevis HLJ59. The extracts from TSFCY were measured to examine pigments, monacolin K contents, total polyphenol and flavonoid contents, DPPH radical scavenging activity, reducing power, ACE inhibitory activity and GABA contents. In this study, the results show that Monascus sp. MK2 and Lactobacillus brevis HLJ59, with Dioscorea batatas Dence. As the substrate can produce pigments (yellow, orange and red), monacolin K contents, total polyphenol and flavonoid contents, DPPH radical scavenging activity, reducing power, ACE inhibitory activity, and GABA contents at 14.03 (yellow), 13.88 (orange), 15.71 (red), 487.9 (MK, mg/kg), 723.8 (TP, mg/kg), 326.4 (TF, mg/kg), 81.7 (DPPH, %), and 1.5 (RP, O.D), respectively. In addition, the showed ACE inhibitory activity and GABA contents was 86.9% and 977.4 mg/kg in EtOH extract, respectively.