• Journal of Food Hygiene and Safety
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• v.38 no.4
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• pp.264-272
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• 2023

The aim of this study was to compare the antioxidant activities and functional contents of Korean conventional and Chinese seed gingers from the Jeollabuk-do Wanju and Chungcheongnam-do Seosan regions. Ginger samples were subjected to steaming treatments for different durations (2-8 h) at 121℃ using an autoclave. The antioxidant activity was evaluated by measuring total polyphenol and flavonoid contents and ABTS and DPPH radical scavenging activities, while functional ingredient contents were analyzed for gingerols and shogaols. The results showed that Wanju conventional seed ginger (WO-2) had the highest total polyphenol (85.24 mg GAE/g) and flavonoid (98.14 RE/100 g) contents, surpassing that of the control in all steamed groups at 6 h. ABTS radical scavenging activity showed a strong correlation with total polyphenol and flavonoid contents. The control groups indicated that Korean conventional seed ginger had 1.0-1.3 times higher gingerol contents compared to Chinese seed ginger. Furthermore, the content of shogaols, considered major functional ingredients, increased significantly with longer steaming durations, reaching the highest content (1,793 mg/kg) at 8 h, which was 1.0-1.8 times higher in Korean conventional seed ginger than that in Chinese seed ginger. These experiments provide valuable data supporting the excellence of Korean conventional seed ginger in the future.

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

• Horticultural Science & Technology
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• v.30 no.3
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• pp.301-307
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• 2012

To develop high value added healthy functional resource from Korean mulberry, the bioactive compounds and antioxidant activities of three different mulberry cultivars were investigated and compared with blueberry and strawberry. Total phenolics, total flavonoids, and trans-resveratrol of 'Daesungppong' were the highest than the 'Suwonppong', whereas those of the strawberries were the lowest. In case of total anthocyanins, 'Daesungppong' was also the highest and followed by blueberry. The antioxidant activities of 'Daesungppong' using DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2'-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid), and FRAP (Ferric reducing antioxidant power) assays were the highest followed by 'Suwonppong'. Meanwhile, there were no significant differences in the antioxidant activities between 'Cheongilppong' and blueberry, and the activities of strawberry were the lowest. Furthermore, there was a strong correlation (r = 0.764-0.897) between DPPH, ABTS, and FRAP assays with the bioactive compounds such as total phenolics, total flavonoids, and total anthocyanins. Therefore, Korean mulberry, especially 'Daesungppong' demonstrated interesting biological properties that suggest its use as a potential source and high value added of natural antioxidant compounds and antioxidant activity.

• Food Engineering Progress
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• v.14 no.2
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• pp.166-172
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• 2010

The extraction of polyphenol and flavonoid from citrus peel was performed by the ethanol, sugar, hot water (80$^{\circ}C$), and subcritical water extraction methods. The maximum yields of total polyphenolic compounds (27.25${\pm}$1.33 mg QE/g DCP, QE and DCP indicate quercetin equivalent and dried citrus peel, respectively) and flavonoids (7.31${\pm}$0.41 mg QE/g DCP) were obtained by subcritical water extraction (SWE) with operating conditions of 190$^{\circ}C$, 1300 psi, and 10 min. The yields by SWE were over 7.2-, and 8.5-fold higher than those of total polyphenols (3.79${\pm}$0.73 mg QE/g DCP) and flavonoids (0.86${\pm}$0.27 mg QE/g DCP) obtained using the ethanol extraction, which showed the highest extraction efficiency among tested conventional methods, respectively. Antioxidant activities of extracts obtained by different methods showed no significant differences. However, the relative antioxidant yield per 1 g dried citrus peel by SWE (190$^{\circ}C$, 10 min) was over 9.5-fold higher than that by the ethanol extraction.

• Korean Journal of Food Science and Technology
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• v.46 no.1
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• pp.33-38
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• 2014

In this study, we investigated the effect of the amount of water added prior to fermentation on the quality of bokbunja (Rubus coreanus Miq.) wine produced. Water was added at 0-fold (A), 1-fold (B), 2-fold (C), 3-fold (D), and 4-fold (E) of the fresh bokbunja weight (w/w), prior to fermentation. Although the amount of bokbunja wine obtained after fermentation increased in proportion to the amount of water added prior to fermentation, the total acidity of the bokbunja wine, adjusted for the weight of bokbunja used in the fermentation process, increased. Moreover, the total phenol and flavonoid content (mg) per weight (g) of bokbunja, in (B), (C), (D), and (E) were 2.86-4.42 and 2.58-3.01 times higher, respectively, than those in (A). These data suggest that different types of bokbunja wines can be produced and different contents of total phenol can be obtained by simply changing the amount of water added prior to fermentation.

• Food Science and Preservation
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• v.17 no.6
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• pp.867-873
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• 2010

The total phenolic contents and the antioxidant activities of methanolic extracts of different parts (fruit, calyx, leaf, stem, and root) of Physalis alkekengi var. francheti were investigated using established in vitro systems including DPPH radical-scavenging, nitrite-scavenging, superoxide anion radical-scavenging activity, measurement of reducing power, and assessment of the metal-chelating effect. The highest extraction yield was from fruit (52.55%), whereas the lowest levels were obtained from root (10.49%) and stem (12.88%).The leaf extract had the highest total phenolic (58.47 mg/g) and total flavonoid (4.83 mg/g) contents, plus the greatest antioxidant activity, as shown by the DPPH radical-scavenging assay, and the highest levels of reducing power at concentrations of 1 and 5 mg/mL. In addition, the calyx also showed good antioxidant activity.These findings indicate that methanolic extracts of leaf and calyx may be useful in the food manufacturing and nutraceutical industries.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.5
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• pp.675-681
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• 2014

This study was conducted to determine the optimal roasting temperature (90, 100, 110, and 120; fixed time of 20 minutes) of small black coffee beans under various roasting conditions. The roasting temperature range and fixed time were the same as our preceding study. After roasting, the general composition, isoflavone contents, and antioxidant activities were measured. As the results of the proximate composition analysis of small black beans according to roasting conditions, only moisture decreased among them, whereas other general compositions were not affected. The DPPH and ABTS radical scavenging activities were the highest at a roasting temperature of $120^{\circ}C$. Total polyphenol and total flavonoid contents were also highest at $120^{\circ}C$. Isoflavone contents showed a positive correlation with DPPH and ABTS radical scavenging activities, as well as total phenol and flavonoid contents. These results suggest that the optimal roasting conditions of small black beans were determined to be $120^{\circ}C$ for 20 minutes.

• FLOWER RESEARCH JOURNAL
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• v.26 no.4
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• pp.202-208
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• 2018

This experiment was conducted to determine optimal hot-air drying time for producing antioxidative calendula tea. The edible calendula was dried in hot air at $60^{\circ}C$ for 5, 10, 15 hours and Hunter's color value was measured and extracted with 95% ethanol as a solvent. The contents of total polyphenol, total flavonoid, total carotenoid and DPPH (2,2 Dipheny-1-picrylhydrazyl) radical scavenging activity were investigated. The correlation between the amount of antioxidant and antioxidant activity was analyzed. As the treatment time increased, the Hunter values of L, a, and b tended to decrease, and the L value and b value decreased significantly at 15 hours. The color change was occurred in all treatments compared with the control, and the total color difference (${\Delta}E$) was the largest at 15 hours treatment. The contents of total flavonoids, total carotenoids and DPPH scavenging activity increased in the 5 hours, but decreased in the 15 hours compared to the 10 hours. The content of total polyphenol was not changed with different treatment time. A positive correlation ($p{\leq}0.01$, r = 0.610) between carotenoids and DPPH radical scavenging activity was demonstrated. The DPPH radical scavenging activity was increased at 5 and 10 hours compared to the control and decreased at 15 hours. Therefore, 5 hours or 10 hours of treatment is appropriate and further studies are needed to determine the specific treatment time.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.12
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• pp.1679-1684
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• 2009

Opuntia humifusa, widely distributed in the southern regions of the Korean peninsula, is known to have bioactive functions and medicinal benefits for treating various diseases such as arteriosclerosis, diabetes mellitus, gastritis, and hyperglycemia. In this study total polyphenol and flavonoid contents of fruit and its anticarcinogenic effects on human breast cancer were investigated. As expected, O. humifusa showed high concentrations of total polyphenol as well as flavonoid as compared to other kinds of cactus. Effects of the water extracts of O. humifusa on the proliferation, G1 arrest and apoptosis of the MCF-7 human breast cancer cells were also examined using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays, and G1 cycle arrest and apoptotic effect of O. humifusa were analyzed by flow cytometry. When MCF-7 cells were treated with different concentrations of hexane, ethyl acetate and water extracts of O. humifusa, water extracts of the fruit significantly decreased viable cell numbers in a concentration dependent manner. A G1 arrest in MCF-7 cells was induced as well. The overall results indicate that water extracts of fruit of O. humifusa would inhibit MCF-7 human breast cancer cell proliferation and induce G1 arrest.

• Korean Journal of Food Science and Technology
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• v.38 no.4
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• pp.521-525
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• 2006

Korean ginseng was heat treated at various temperatures (110, 120, 130, 140 and $150^{\circ}C$) and times (1, 2, 3, 4, and 5 hr). The heat treated ginseng extract was analyzed for the total polyphenol content, total flavonoid content, DPPH free-radical scavenging, 5-HMF and ginsenoside. The total phenolics and flavonoid content increased with increasing treatment temperature and time. The highest total phenolics content was 29.46 mg/g (d.b) in $150^{\circ}C$ for 1hr (control: 2.68 mg/g). The highest total flavonoid content was 4.75mg/g (d.b) in $150^{\circ}C$ for 2hr (control: 0.39 mg/g). The antioxidant activity increased until $140^{\circ}C$ for 3 hours. An extension of the treatment time did not have any effect, and the antioxidant activity decreased at temperatures higher than $150^{\circ}C$ for more than 2 hours. The content of ginsenoside $Rg_1$, Re, $Rb_2$ and Rb3 rapidly decreased with increasing treatment temperature and time. Ginsenoside $Rg_3$ and $Rh_2$ were newly produced, or their contents increased with increasing treatment temperature and time.