• Korean Journal of Food Science and Technology
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• v.46 no.6
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• pp.671-676
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• 2014

This study was designed to evaluate the changes in the physicochemical properties and antioxidant activity of Dutch coffee (cold brew) under different conditions of extraction and storage. Dutch coffee was extracted from ground coffee soaked in water at 4 or $20^{\circ}C$ and stored for 8 weeks at 4 or $20^{\circ}C$. The storage temperature affected the decline in pH and increase in acidity compared to the extraction temperature. The total phenol content partly decreased during the storage period. As the extraction temperature increased, the ABTS [2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)] and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical-scavenging activities also increased; in fact, DPPH radical-scavenging activity showed a general increase. As the storage time prolonged, the caffeine content decreased, but the contents of caffeic acid and chlorogenic acid increased. The results for all kinds of samples indicated that the general bacterial count was <1 CFU/mL, which indicated that the coffee can be stored for and consumed within 8 weeks.

• 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.

• Korean Journal of Food Science and Technology
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• v.47 no.4
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• pp.539-543
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• 2015

A hardy kiwifruit is a good source of phenolics and antioxidants. This study was aimed at investigating the effects of hot air drying at three different temperatures (35, 50, and $70^{\circ}C$) for 24 h on the total phenolic and flavonoid contents and the antioxidant capacity of hardy kiwifruits of Actinidia arguta ${\times}$ A. deliciosa cv. Mansoo. Dried kiwifruit extracts were produced using 80% (v/v) aqueous ethanol under homogenization. Hot air drying lowered the total phenolic and flavonoid contents and decreased the antioxidant capacity in the dried kiwifruits compared with their fresh counterparts. The results also revealed high positive linear correlations of antioxidant capacity with total phenolic and flavonoid contents, indicating that phenolics are the major contributors to antioxidant capacity. Our results suggested that an optimal drying process must be determined for industrial application in order to obtain dried kiwifruits with increased antioxidant capacity for consumers.

• Korean Journal of Food Science and Technology
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• v.49 no.5
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• pp.474-479
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• 2017

Five types of coffee bean, which are usually imported and consumed in Korea, were roasted at $250^{\circ}C$ for 15 min and extracted by using a filter coffee machine. The physicochemical properties, functional components, and radical scavenging activity of coffee bean extracts were investigated. The pH of extract was the highest among the extracts and the soluble solid contents of extracts were $0.9-1.0^{\circ}Bx$. The acidity of the extracts was in the range from 0.46-0.55%, which was not significantly different from the control. Indonesian coffee bean extract showed the highest brown color intensity and contained the highest amounts of caffeine and chlorogenic acid. The highest total polyphenol content was found in Kenyan coffee bean extract. Coffee bean extracts from Indonesia and Kenya showed significantly higher radical scavenging activities than the other extracts. This study showed that coffee bean extracts from Indonesia and Kenya contained a large number of bioactive compounds and high antioxidant activity.

• Korean Journal of Food Science and Technology
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• v.49 no.5
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• pp.480-485
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• 2017

This study was conducted to examine the antioxidant activity of 80% ethanol extract of celery seeds and to verify the effectiveness of extracts as a natural antioxidant to improve the stability of oil-in-water emulsions. The radical scavenging activity of 80% ethanol extract of celery seeds was significantly increased at 0.125, 0.25, and 0.5 mg/mL (p<0.05). Additionally, the total phenolic content and FRAP value were equal to $8.2{\pm}2.3mol$ tannic acid equivalent/g extract and $195.0{\pm}12.6mol$ ascorbic acid equivalent/g extract, respectively. The headspace oxygen content was significantly higher in the group treated with 80% ethanol extract of celery seeds than in the control group (p<0.05). The amounts of lipid hydroperoxide and conjugated diene were significantly reduced compared to the control group (p<0.05). The results showed that the extract of celery seeds had excellent antioxidant ability and it could be used as a natural antioxidant owing to the increased oxidative stability of the emulsified product.

• The Korean Journal of Food And Nutrition
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• v.31 no.1
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• pp.149-159
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• 2018

The change of quality and physicochemical characteristics of mung-bean flours after germination and roasting treatment were evaluated. The moisture content of the roasted mung-bean flours decreased significantly according to the roasting temperatures and times, and the crude ash, protein and fat contents increased. The lightness of the roasted mung-bean flours significantly decreased, and the redness and yellowness increased. The water binding capacity of the roasted mung-bean flours without and with germination were 151.71 and 192.77% at $240^{\circ}C$ for 20 min, respectively. The water solubility index and swelling power decreased with an increase in roasting temperatures and times. The phenolic compounds and radical scavenging activity of the roasted mung-bean flours increased with an increase in the roasting temperatures and times. The total polyphenol contents of the roasted mung-bean flours without and with germination were 4.81~7.71 and 4.22~5.63 mg GAE/g, and the total flavonoid contents were 2.46~3.05 and 2.45~2.87 mg CE/g, respectively. The DPPH radical scavenging activity of the roasted mung-bean flours, without and with germination, were 106.83~376.08 and 174.41~346.70 mg TE/100 g, and the ABTS radical scavenging activity was 251.67~534.31 and 274.39~430.02 mg TE/100 g, respectively. As a result, it is necessary to set quality standards for each application considering the quality and antioxidant properties of the roasted mung-bean flours.

• The Korean Journal of Food And Nutrition
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• v.31 no.1
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• pp.135-142
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• 2018

We investigated the influence of germination and high hydrostatic pressure (HHP) treatment conditions on the conversion of functional compounds and antioxidant activity in adzuki bean. The adzuki bean germinated at $25^{\circ}C$ for three- or six-days, and was later subjected to HHP at 0.1, 50, 100, or 150 MPa for 24 h. The highest polyphenol content (5.36 mg gallic acid equivalents (GAE)/g) and flavonoid content (0.91 mg catechin equivalents (CE)/g) were observed after germination for six days and HHP treatment at 100 MPa for 24 h, respectively. The total phenolic acid contents increased with increasing applied pressure from 88.86 to $208.26{\mu}g/g$ (100MPa, 24h). Phenolic acids are divided into two categories; those that exhibit increased content upon HHP treatment, and those that exhibit decreased content. The increasing phenolic acids were gallic acid, chlorogenic acid, (+)-catechin, ${\rho}-coumaric$ acid, ferulic acid, heperidin, salicylic acid, protocatechuic acid, cinnamic acid, naringenin. The total anthocyanin content decreased with increasing applied pressure from 22.42 mg/100 g to 6.28 mg/100 g (150 MPa, 24 h). The highest ABTS radical scavenging activity (8.02 mg eq AA/g) and DPPH radical scavenging activity (1.22 eq Trolox/g) were observed after germination for six days and HHP treatment at 100MPa for 24h, respectively. These results suggested that the combination of HHP and germination can lead to improved functionality in adzuki bean.

• Journal of Life Science
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• v.30 no.7
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• pp.581-591
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• 2020

This study investigated the probiotic properties and physiological activities of Korean fermented foods such as sikhae, young radish kimchi, and bean-curd dregs. Among the isolated lactic acid bacteria, Pediococcus inopinatus BZ4, Lactobacillus plantarum SH1, Lactobacillus brevis SH14, Pediococcus pentosaceus YMT1, and Leuconostoc mesenteroides YMT6 demonstrated a greater than 60% survival rate at pH 2.5, along with an excellent survival rate even at 0.3% bile acid. These five bacteria showed strong flocculation ability in autoaggregation and coaggregation tests, indirectly clustering useful micro-organisms and inhibiting the attachment of pathogenic bacteria. In a cell surface hydrophobicity test, these bacteria showed adhesion to three solvents (ethyl acetate, chloroform, and xylene) and high hydrophobicity, thereby indicating excellent indirect cell adhesion to intestinal cells. The cell-free supernatants and intracellular extracts of the five lactic acid bacteria showed antioxidative activity in the form of 2,2-Diphenyl-1-picrylhydrazyl and 2,2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging ability and lipid peroxidation inhibition. Antimicrobial activities were also observed in four pathogenic bacteria, namely E. coli KCTC 2571, H. pylori HPKCTC B0150, L. monocytogenes KCTC 13064, and S. aureus KCTC 1916. These results demonstrate that these five lactic acid bacteria could be used as probiotics with antioxidant and antimicrobial properties.

• KSBB Journal
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• v.32 no.1
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• pp.63-70
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• 2017

Bamboo leaf has many nutritional and bioactive compounds such as polyphenols, and it can be used for various foods application. Fermentation is one of appropriate processes that can affect the nutrition, taste and flavor, and antioxidant activities of foods. In this study, a representative domestic bamboo tree (Sasa coreana Nakai) leaves were fermented by Bacillus subtilis KCCM 11315 and the changes of carbohydrates, minerals, amino acids, and phenolic compounds and antioxidant activities were investigated before and after fermentation. During the fermentation period, firstly, the leaf was softened and turned to brown. The constituent carbohydrates were slightly increased from $432.09{\pm}5.38mg/g$ to $458.42{\pm}7.39mg/g$, and free sugars decreased by 95% from $28.12{\pm}2.03mg/g$ to $1.4{\pm}0.14mg/g$. Mineral was $20987.5{\pm}345.1{\mu}g/mL$, which was slightly increased after the fermentation compared to $20804.1{\pm}364.6{\mu}g/mL$ before that. The total amino acids were increased to $73881.94{\pm}137.59mg/100g$ compared to $58464.51{\pm}109.12mg/100g$ before fermentation, and free amino acids decreased by more than 85% from $32782.67{\pm}92.49mg/100g$ to $4827.83{\pm}19.76mg/100g$. Total polyphenols content (TPC) increased from $25.51{\pm}1.04GAE^*mg/g$ to $35.34{\pm}0.91GAE^*mg/g$, and the total flavonoid content (TFC) increased to $80.57{\pm}0.22QE^*mg/g$ compared to $69.64{\pm}0.26QE^*mg/g$. The total catechin content (TCC) of TFC was decreased from $69.64{\pm}0.94mg/L$ to $58.23{\pm}0.76mg/L$. The DPPH radical $IC_{50}$ of bamboo leaves decreased to $2624.85{\pm}37.03{\mu}g/mL$ and the ABTS radical $IC_{50}$ of $187.26{\pm}4.78{\mu}g/mL$ was increased after the fermentation. These results could be used as essential nutritional data before developing processed food products using the bamboo leaf.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.6
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• pp.677-683
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• 2008

The antioxidant activities of Wisteria floribunda flowers (WFF) were evaluated. The samples were prepared by extracting separately two different colored flowers (purple and white) with four different solvents (methanol, ethanol, acetone, and water). The antioxidant properties were evaluated by determining total phenolic contents (TPC), radical scavenging activity (RSA), and reducing power (RP). Water extract from purple WFF and ethanol extract of white WFF showed the highest total phenol contents (491 and 787 ${\mu}M$ gallic acid equivalents), respectively. Water extracts of purple and white WFF also showed higher RSA. In the case of RP, ethanol extract of purple WFF, methanol and water extracts of white WFF showed relatively higher values. The 200 ${\mu}M$ $H_2O_2$ induced oxidative DNA damage in human leukocytes was significantly inhibited with WFF extracts excluding ethanol and acetone extracts of purple flowers. These results suggest that W. floribunda flowers have significant antioxidative activity and protective effect against oxidative DNA damage.