• Korean Journal of Agricultural Science
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• v.45 no.1
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• pp.19-27
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• 2018

To study the effect of natural anti-microbial chemicals on the growth and quality of chili peppers, chitosan ($100mg/L^{-1}$), stevia ($250mg/L^{-1}$), and the mixture of both chemicals at the same concentration were sprayed after planting at 1-week interval throughout the experimental period. Plant height was measured twice after the $3^{rd}$ and $4^{th}$ applications. Plant height was numerically reduced in all chemical treatments compared to that of untreated control; however, there was no statistical difference between treatments. The fruit quality was examined at commercial maturity, and only minor differences were found in fruit color, length, and dry matter content between the treatments. Although a statistical difference was not present for soluble sugars levels, total phenolics, and capsaicin contents, yield in all chemical treatments significantly increased compared to untreated control. The effect on yield increase was greater at the late harvest season regardless of treatments. Total yield of 4 harvests was higher for the chitosan treatment than other treatments. During the experiment, the entire experimental field was waterlogged for 1 day due to sudden heavy rainfall, which resulted in the occurrence of bacterial browning disease in all treatments. The rate of disease occurrence and the degree of severity, however, were much lower in the chitosan treatment. In conclusion, the potential of chitosan as an alternative antimicrobial agent was confirmed in chili peppers in this study. Further research is required on stevia as an alternative chemical for disease control in chili peppers.

• Korean Journal of Food Science and Technology
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• v.49 no.1
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• pp.44-49
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• 2017

Subcritical water extraction can be used to selectively extraction compounds by varying the temperature-dependent dielectric constant of water. This study investigated subcritical water extraction of decursin and nodakenin yields from Angelica gigas Nakai (AN) quantitatively and qualitatively by HPLC, and HPLC-ESI/MS. Total phenolics, total flavonoid contents, and antioxidant activity were determined by DPPH and ABTS radical scavenging activity, including the effects of varying the extraction conditions of temperature ($110-200^{\circ}C$) and time (1-20 min) under high pressure (10 MPa). By subcritical water extraction under operating conditions of $120-130^{\circ}C$, the maximum yields of decursin ($6.64{\pm}0.42%$ in the dried material) and nodakenin ($3.71{\pm}0.28%$ in the dried material) were obtained. From $190-200^{\circ}C$ the maximum yields of total phenolics ($75.97{\pm}1.64mg$ gallic acid equivalent/g AN), flavonoids ($8.56{\pm}1.10mg$ quercetin equivalent/g AN), DPPH ($63.07{\pm}1.71%$), and ABTS ($72.32{\pm}2.82%$) were obtained.

• Food Science and Preservation
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• v.23 no.4
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• pp.553-559
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• 2016

The purpose of this study was to determine the content of phenolics and various anthocyanin compounds, and antioxidant and anticancer activities of the extracts from pomergranates, which were produced in two different regions including Goheung, Korea and California, USA. These pomergrantes were divided into juice, pericarp, and seed parts and each part was extracted with 95% methanol. Content of total phenolics [mg chlorogenic acid equivalents/kg DW] was highest in pericarp, followed by juice and seeds from pomergrantes in both regions. The anthocyanins identified in pomegranate fruit were cyanidin-3,5-diglucoside chloride (Cy3,5G), cyanidin-3-O-glucoside chloride (Cy3G), delphini din-3,5-di-O-glucoside chloride (Dp3,5G), delphinidin-3-O-glucoside chloride (Dp3G), pelargonidin-3,5-di-glucoside chloride (Pg3,5G), and pelargonidin-3-glucoside chloride (Pg3G). Among these, cyanidin-3,5-diglucoside chloride (Cy3,5G) was the major anthocyanin in California pomegranate fruit juice and Goheung pomegranate fruit pericarp. DPPH (1,1-diphenyl-2-picryl hydrazyl radical) free radical scavenging activity was dose-dependently increased, and was higher in pericarp part than juice or seed parts from pomergrantes in both regions. By MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay, pericarp extracts from pomergrantes in both regions showed the highest anticancer activity, which was higher on Calu-6 for human pulmonary carcinoma than SNU-601 for human gastric carcinoma. Correlation between polyphenols and anticancer activity on Calu-6 was determined to be in the range of $r^2=0.8904$ to 0.9706.

• Food Science and Preservation
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• v.17 no.1
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• pp.100-106
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• 2010

The contents and antioxidant activities of various polyphenolic fractions from commercial cocoa powder were investigated. Total phenolics extracted by 0.01 M HCl, ethyl acetate, and acidic methanol, from an 80% (v/v) methanolic extract of cocoa, were 19.25, 202.24, and 295.83 mg/g, respectively. Each fraction was capable of scavenging DPPH radicals in a concentration-dependent manner. Among the various fractions, the acidic methanol fraction had the highest ABTS radical scavenging ability. The reducing power of the 0.01 M HCl, ethyl acetate, and acidic methanol fractions were 0.44, 3.15, and 3.87, respectively, at 1,000 ${\mu}g/mL$. Antioxidant activities, as assessed by $\beta$-carotene bleaching and linoleic acid autoxidation, of the various phenolic fractions from cocoa decreased in the order acidic methanol > ethyl acetate > 0.01 M HCl. Inhibition of $\beta$-carotene bleaching mediated by the acidic methanol fraction was similar to that of the ethyl acetate fraction. The values were 60.18% and 58.97%, respectively, at 1,000 ${\mu}g/mL$. Therefore, cocoa and cocoa-containing products may contain natural antioxidants useful in prevention of diseases associated with aging.

• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.5
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• pp.661-667
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• 2014

To investigate the anti-diabetic and antioxidant effects of Opuntia humifusa cladodes, O. humifusa cladodes powder was extracted with 75% ethanol and fractionated with various solvents. Among the extracts fractionated with various solvents, ${\alpha}$-amylase and ${\alpha}$-glucosidase inhibitory activities of O. humifusa cladodes were highest ($89.94{\pm}1.15%$ and $29.01{\pm}3.03%$, respectively) in the ethyl acetate fraction. Further, total phenolic and flavonoid contents of the ethyl acetate fraction were the highest ($196.02{\pm}5.26$ and $114.00{\pm}10.03{\mu}g/mg$, respectively). DPPH and ABTS radical scavenging activities increased according to the concentration of O. humifusa cladodes extract, and those of the ethyl acetate fraction were the highest. Ferric reducing antioxidant powers of chloroform and the ethyl acetate fraction were higher than those of other fractions. Overall, the ethyl acetate fraction of O. humifusa cladodes showed the highest anti-diabetic and antioxidant effects. Results indicate that O. humifusa cladodes powder has potential as a useful ingredient with anti-diabetic and antioxidant effects.

• Food Science and Preservation
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• v.12 no.1
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• pp.62-67
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• 2005

Microwave-assisted extraction (50 W, 2,450 MHz, MAE) with properties of selective heating and subsequent extraction for certain phytochemicals from natural materials was applied to pre-establish the extraction conditions for total yield total phenolics, and electron donating ability (EDA) from Brossica oleacea. The experiments with $50\%$ EtOH solvent showed that 20 mesh in particle size of cabbage flake $(moisture\;4.5\%)$ and 1:10 (g/mL) in the sample to solvent ratio for both raw $(moisture\;90.2\%)$ and flake cabbages were optimal for MAE efficiency. Under these conditions, total yield increased with extraction tim, which was highest for raw cabbage extract in $50\%\;EtOH$ solvent followed by $100\%\;EtOH$ and water. While that of flake cabbage extracts was highest in $50\%\;EtOH$ followed by water and $100\%\;EtOH$. The contents of total phenolics and EDA in extracts gradually increased after 3 min of MAE, which were highest when using $100\%\;EtOH$ solvent followed by $50\%\;EtOH$ and water in raw cabbage and $50\%\;EtOH$ followed by water and $100\%\;EtOH$ in flake cabbage, respectively.

• Korean Journal of Plant Resources
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• v.27 no.4
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• pp.279-285
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• 2014

Nutritional composition, including total phenolics, tannins and nutrient components, of acorns of Q. actissima, Q. serrata, Q. variabilis and Q. mongolica were analyzed. Acorns were collected from each tree species, which were grown in a seed orchard. Contents of both total phenolics and tannins in acorns of Q. serrata were higher than those of Q. actissima (p<0.05). Interestingly, Q. serrata contained the highest amount of water soluble tannins (71 mg/g dw) and the lowest levels of water insoluble tannins (8.1 mg/g dw) among 4 oak species, resulting that acorns of Q. serrata had the lowest proportion of insoluble tannins. Among 4 oak species tested, Q. mongolicav acorns contained the highest levels of both total dietary fiber (TDF) and ascorbic acid, while the content of beta-carotene in Q. mongolicav was 52-fold lower than that in Q. variabilis ($520{\mu}g/100g$). Our result showed that nutritional composition of acoms was significantly different between oak species, indicating that tastes or nutritional values might be different as well among major oak species in Korea.

• Food Science and Preservation
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• v.17 no.5
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• pp.644-651
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• 2010

We prepared sikhe (CSE/BR-SH) using corn silk extract and black rice. The pH decreased during saccharification, from pH $5.88{\pm}0.03$ to pH $5.67{\pm}0.02$ after 6 h. However, the brix and reducing sugar contents increased during saccharification of CSE/BR-SH, with the highest levels ($7.6{\pm}0.05$ brix and $4.012{\pm}0.05$ g/l, respectively) being attained at 6 h. Amylase activity increased to 116.12% of control values 1 h after saccharification of CSE/BR-SH, and decreased thereafter. CSE/BR-SH was light purple in color. Soluble phenolic concentration increased markedly from an initial 8.43 g/l to 23.09 g/l at the end of saccharification (6 h), as did DPPH radical-scavenging activity (from an initial 17.3% to 70.98%), Increases were noted in all of ABTS radical-scavenging activity (from 40.25% to 75.32%), reducing power (from 0.241 to 0.682), and ferric reducing antioxidant power (FRAP) (from 0.288 to 1.071).

• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.880-886
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• 1999

The present study was attempted to investigate the contents of antioxidant nutrients in green juice of Angelica keiskei, kale, carrot, celery, cucumber. All 5 green juice were found to contain antioxidant nutrients such as ${\beta}-carotene$, vitamin E, vitamin C, Se, Cu, Mn, Zn and phenols. ${\beta}-carotene$ contents of carrot, kale, Angelica keiskei, celery and cucumber juice were 5909.0, 3285.3, 1398.4, 176.7 and 61.4 mg/l00 g, respectively. ${\alpha}-tocopherol$ contents of 5 green juices were $0.04{\sim}1.41$ mg/l00 g. Kale juice had highest ${\alpha}-tocopherol$ and celery juice contained lowest, kale juice also contained highest vitamin C (105.1 mg/l00 g) and Angelica keiskei, cucumber, celery and carrot had vitamin C contents of 31.4, 9.3, 7.5 and 5.2 mg/l00 g, respectively. Angelica keiskei had highest amount of antioxidant minerals among the sample such as Cu (0.40 mg/l00 g), Mn (0.5 mg/l00 g), Zn (0.24 mg/l00 g), Se $(0.61\;{\mu}g/kg)$. Kale was the second best source of antioxidant minerals which were Cu (0.45 mg/l00 g), Mn (0.22 mg/l00 g), Zn (0.24 mg/l00 g), Se $(0.33\;{\mu}g/kg)$. However, celery and cucumber were poor in antioxidant minerals. Total phenolic contents of 5 green juices were $0.01\;{\sim}0.05%$, kale juice also had highest total phenolics among the samples.