• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.5
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• pp.591-597
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• 2012

This study was conducted to investigate the changes in chemical components and antioxidant activities of dried jujube ($Zizyphus$ $jujuba$ Miller) with different aging temperatures ($60^{\circ}C$, $70^{\circ}C$, and $80^{\circ}C$) and durations (5 days, 10 days, 15 days, 30 days, and 50 days). The browning index increased from 0.124 to 1.998 with increased aging temperature and duration. As aging duration increased, fructose, glucose, and sucrose content decreased from 24.96% to 4.96%, from 22.23% to 4.41%, and from 18.41% to 0%, respectively. Reducing sugar content decreased from 351.52 mg/g to 155.96 mg/g as aging temperature and duration increased. Total acidity slightly increased from 1.61 to 3.13%. 5-Hydroxymethyl-2-furaldehyde increased from 0.002 mg/g to 38.84 mg/g, respectively. As aging temperature and duration increased, total polyphenol content increased from 15.98 mg/g to 38.61 mg/g. DPPH and ABTS radical scavenging activities increased from 4.03 mg trolox eq/g to 22.22 mg trolox eq/g, and from 2.11 mg ascorbic acid eq/g to 13.39 mg ascorbic acid eq/g, respectively. Reducing power increased rapidly in the first stage and then slowly increased afterward.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.10
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• pp.1231-1237
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• 2008

This study was conducted to investigate the functional biological effects of hot water and ethanol extracts from Taraxacum mongolicum (TM). Then, the hot water and ethanol extracts of TM were measured for total flavonoids content, total phenolics content, electron donating ability, nitrite-scavenging ability, SOD-like activity, tyrosinase inhibitory effect, and elastase inhibitory effect. Total flavonoids contents of hot water and ethanol extracts from TM were 7.80$\pm$0.97 mg/g and 9.12$\pm$0.51 mg/g, respectively, and total phenolics contents were estimated as 54.20$\pm$1.95 mg/g for water extract and 79.43$\pm$4.44 mg/g for ethanol extract. The $RC_{50}$ values for electron donating ability of hot water and ethanol extracts were 943.98 $\mu$g/mL and 309.41 $\mu$g/mL. SOD-like activity and nitrite-scavenging ability were dependent on concentration of hot water and ethanol extracts, and the activity of ethanol extract was higher than that of hot water extract. However, hot water and ethanol extracts from TM showed no inhibitory activities on the elastase and tyrosinase inhibitory activities. Based on the above results, the ethanol extract of TM seems to be the most pertinent for use as functional food and cosmetic.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.9
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• pp.1357-1362
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• 2013

The objective of this study was to evaluate the effects of far-infrared (FIR) irradiation on the antioxidant and tyrosinase inhibitory activities of Schizonepeta (S.) tenuifolia. After FIR irradiation of S. tenuifolia for 30 min at 70, 90, or $110^{\circ}C$, water extracts (2 g/100 mL) were prepared at $60^{\circ}C$ for 1, 3, or 5 h. Total phenol content (TPC), 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activities (RSAs), and tyrosinase inhibitory activity of the extracts were determined. TPC, antioxidant and tyrosinase inhibitory activities of the extracts increased significantly with increasing FIR irradiation temperature of S. tenuifolia. For example, irradiation at $110^{\circ}C$ for 5 h increased TPC, DPPH RSA, ABTS RSA, and tyrosinase inhibitory activity of the extract from 204.64 to $618.67{\mu}g$ gallic acid equivalents/mL, from 30.15 to 80.84%, from 24.43 to 55.33%, and from 7.05 to 33.65%, respectively, compared to the extract of untreated S. tenuifolia. These results indicate that FIR irradiation may be useful as a processing method for enhancing the quality of S. tenuifolia.

• 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.

• Korean Journal of Food Science and Technology
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• v.46 no.6
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• pp.757-761
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• 2014

The objective of this study was to investigate the content of phenolic compounds and their contribution to antioxidant activity in the seed coats, dehulled and whole black and yellow soybeans. The total phenolic and total anthocyanin contents were analyzed. FRAP, DPPH and ABTS assays were carried out to determine the antioxidant activities. The 100-seed weight and color values were also analyzed. Black seed coats had significantly greater total phenolic and total anthocyanin contents as compared to whole beans, dehulled beans, and yellow seed coats. Moreover, black seed coats exhibited the highest antioxidant activity among the samples, regardless of the utilized method. The antioxidant activities determined in all assays positively correlated with the total phenolic ($0.980{\leq}r{\leq}0.991$) and anthocyanin contents ($0.990{\leq}r{\leq}0.997$) as well as among themselves ($0.992{\leq}r{\leq}0.996$). It is anticipated that the information generated from this study will help support the development of soybean products for improving health.

• Food Science and Preservation
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• v.21 no.2
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• pp.181-186
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• 2014

This study was conducted to that investigate the quality characteristics of wet-ground whole-grain buckwheat powder for the buckwheat husk. The particle size of buckwheat rice was 74.84 ${\mu}m$, which was approximately four to five times larger than wet-ground whole buckwheat by wet grinding. The particle size showed that there was no significant difference after 90 min on wet grinding. The total phenolics and total flavonoids contents of the whole buckwheat powder were higher than those of buckwheat rice, and they gradually increased wet grinding progressed. The rutin contents of the buckwheat increased after wet grinding and was 152.90 ppm at 90 min. There was no significant difference in the quercetin contents after wet grinding at different times. The mineral contents (Ca, K and Mg) of the whole buckwheat powder were greater than those of the buckwheat rice. Further, Zn and Mn were detected in the whole buckwheat powder. The total amino acid content of the whole buckwheat powder increased to 22.27 mg%, and the important glutamic acid increased from 14.58 to 30.45 mg%. These study results were based on 90 min wet-grinding time for whole-buckwheat-powder manufacture. Whole buckwheat powder manufactured through wet grinding can be used as an active ingredient of buckwheat husk.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.4
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• pp.512-520
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• 2008

In order to examine the effective components and antioxidative characteristics of Acanthopanacis cortex, response surface methodology was used to optimize the hot water extraction process by analyzing and monitoring the extraction condition characteristics. The total extraction yield was optimized using the extraction temperature of $84.28^{\circ}C$, extraction time of 3.59 hr and 18.37 mL/g as the amount of solvent per sample. For the effective component of eleutheroside E, the optimal extraction temperature, time and amount of solvent per sample were $81.16^{\circ}C$, 3.56 hr, and 19.06 mL/g, respectively; also, for total phenolics, the optimal conditions were $88.45^{\circ}C$, 4.33 hr, and 21.12 mL/g, respectively. Regression equations were deduced for each variable and then eleutheroside E, chlorogenic acid, and antioxidative characteristics were superimposed with the optimal conditions to obtain values for each extraction process factor. The predicted results were $81{\sim}88^{\circ}C$, $3.5{\sim}4.3hr$, and $18{\sim}21mL/g$, respectively. The estimated values for the optimal extraction conditions of Acanthopanacis cortex's effective components and antioxidative characteristics were similar to the experimental results.

• Food Science and Preservation
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• v.31 no.4
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• pp.673-681
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• 2024

This study was conducted to develop kombucha with better functionality. The developed kombucha (CK) was prepared using the sugar extracts from fruits of Cudrania tricuspidata (Carrière) Bureau ex Lavallée instead of the sugar, which is used as a substrate for SCOBY in conventional kombucha (K). During fermentation, the soluble solids content significantly decreased in CK compared to K, and the pH change decreased rapidly in CK compared to K. On the 14^th day of fermentation, the weight of the SCOBY in CK was higher than that in K. Immediately after preparation, K contained only sucrose, but CK contained sucrose, glucose, and fructose. SCOBY appears to use glucose and fructose preferentially during fermentation. K contained acetic acid and citric acid right after preparation. However, as fermentation progressed, the composition changed to acetic acid, citric acid, and lactic acid. At the same time, CK initially consisted of citric acid, lactic acid, and acetic acid. However, acetic acid and citric acid increased but lactic acid decreased significantly on the 14^th day of fermentation. In the cytotoxicity studies, the CK showed a proliferation-promoting effect on normal lung cells (MRC-5) and strong cytotoxicity against human lung cancer cells (A549). These results suggest that the kombucha made from sugar extracts of C. tricuspidata fruits can be used as a more functional beverage than regular kombucha.

• Korean Journal of Food Science and Technology
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• v.38 no.5
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• pp.699-706
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• 2006

The antioxidative and antimicrobial activities of Euphorbia jolkini extracts were investigated. Total polyphenohc compounds extracted were approximately as follows: 162.08 mg/g from ethanol, 12.64 mg/g from n-hexane, 48.11 mg/g from dichloromethane, 544.08 mg/g from ethyl acetate, 176.42 mg/g from butanol, and 30.00 mg/g from water. The ethylacetate fraction of this extraction showed the highest antioxidative activity $(IC_{50})$: DPPH radical scavenging capacity was measured at $8.38\;{\mu}g/mL$, xanthine oxidase inhibitory activity was $466.01\;{\mu}g/mL$, superoxide radical scavenging capacity was $11.39\;{\mu}g/mL$, and nitric oxide scavenging capacity was $332.11\;{\mu}g/mL$. Antimicrobial activities were determined by paper disc method and minimum inhibitory concentration of E. jolkini extracts against food-borne pathogens and spoilage bacteria. The growth inhibition curves of E. jolkini extracts against Bacillus cereus, Listeria monocytogenes, and Escherichia coli were also determined. These results suggest that the ethylacetate fraction of E. jolkini has strong antimicrobial activity against the all species of microorganisms as well as strong antioxidant activity.

• Korean Journal of Food Science and Technology
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• v.37 no.1
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• pp.67-72
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• 2005

Antioxidative activity of crude saponin fraction (CSF) prepared from Basidiomycota cultured with fresh ginseng (Panax ginseng C.A. Meyer) as substrate was investigated by analyzing CSFs for ginsenoside and phenolic compounds. On TLC chromatogram, ginsenosides such as $Rg_{2},\;Rg_{3}$, and $Rh_{1}$ which were rare in fresh ginseng, were identified. CSF of Phellinus linteus culture product showed the highest total phenolic content and electron donating ability (EDA), suggesting phenolic compounds contribute to EDA. In vitro lipid peroxidation was inhibited most by CSF of Ganoderma lucidum, indicating that the highest EDA does not imply highest inhibition against lipid peroxidation. Tyrosinase was also inhibited mostly by CSF of G. lucidum. These results suggest culture of Basidiomycota with fresh ginseng has more active substances than fresh ginseng alone.