• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.11
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• pp.1343-1349
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• 2017

This study was carried out to determine the simultaneous extraction conditions of functional components (lutein, ${\beta}$-carotene, total polyphenol, flavonoids, and phenolic compounds) from sweet potato leaves and to evaluate the antioxidant activities. Extraction conditions included different ethanol concentrations (1st extraction: 99.9% ethanol; 2nd extraction: 50~90% ethanol) and times (30, 60, and 90 min). The highest values of lutein and ${\beta}$-carotene content were obtained by the 2nd extraction at an ethanol concentration of 90%. The extraction yields of lutein and ${\beta}$-carotene decreased with increasing extraction time. The maximum polyphenol, flavonoid, and total phenolic acid contents and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and 1,1-diphenyl-2-picrylhydrazyl radical scavenging activities were 32.3 mg gallic acid equivalent/g, 17.0 mg catechin equivalent/g, 2,842.6 mg/100 g, 17.0 mg ascorbic acid equivalent/g, and 1.94 mg/mL ($IC_{50}$) at the 2nd extraction with an ethanol concentration of 60%. The optimum extraction conditions were as follows; ethanol concentrations of the extraction solvent were 99.9% (1st extraction) and 60% (2nd extraction), and extraction time was 30 min.

• Korean Journal of Food Science and Technology
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• v.47 no.6
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• pp.765-771
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• 2015

This study was performed to examine the quality characteristics and antioxidant activity of the curd yogurt with different contents (0.5-2%, w/w) of acanthopanax powder (AP). The pH decreased with increasing AP content until 16 h, whereas the treated groups showed higher pH levels than the control group after 20 h. The viscosity and the viable cell counts of the yogurt with 2% AP were lower than those of the control group during fermentation, significantly. Color values of AP yogurt were lower in terms of brightness, whereas redness and yellowness values were higher compared to the control group. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and soluble content significantly increased with increasing AP content. Consumer acceptability score of yogurt with 0.5% AP was ranked higher than other yogurts. Yogurt added with 0.5% AP showed no differences in pH, titrable acidity, and viable cell counts compared to the control group after storage at $4^{\circ}C$ for 14 days.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.5
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• pp.506-519
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• 2017

This study evaluated the protein recovery and functional properties and biological activity of boiled and steamed process water (BPW and SPW, respectively) generated from the preparation of concentrated roe of bastard halibut (BH; Paralichthys olivaceus), skipjack tuna (ST; Katsuwonus pelamis), and yellowfin tuna (YT; Thunnus albacares) using the cook-dry process. The protein loss from the water extracts (EXT) of 100 g of roe protein was 15.05-19.71% and was significantly (P<0.05) higher than that of BPW (5.47-10.34%) and SPW (3.88-8.18%). The foam capacity of BPW (166-203%) and SPW (15-194%) was better than that of EXT. The emulsifying activity index of the original samples was lower than those ($15.40-107.86m^2/g$) of diluted protein samples. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and the reducing power of BPW and SPW were stronger than those of EXT. The 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid ($ABTS^+$) radical scavenging activity of EXT (0.028-0.045mg/mL) was significantly higher those of BPW and SPW. The angiotensin I-converting enzyme (ACE) inhibitory activity of SPW was the highest for BH (1.04 mg/mL), followed by YT and ST. The predominant amino acids in SPW were Glu, Ala, Leu, and His. These results demonstrate that processing water containing diluted organic components, including protein, can be consumed directly by humans as a functional reinforcing material after appropriate concentration processes.

• Korean Journal of Plant Resources
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• v.27 no.5
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• pp.401-414
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• 2014

In an attempt to evaluate licorice quality based on its biological activity, we grafted an on-line high-performance liquid chromatography (HPLC) bioassay method into the previously established HPLC analysis method. The common antioxidant peaks in licorices of various origin were observed through an on-line HPLC/DPPH system leading to a decrease in absorbance at 517 nm for 2,2-diphenyl-1-picrylhydrazyl (DPPH). Among them, the licorice from Youngju possessed the highest activity. Therefore, three active standard compounds from the dehydroglyasperin C, dehydroglyasperin D, and isoangustone A, were isolated and elucidated by medium pressure liquid chromatography (MPLC) and instrumental analysis such as nuclear magnetic resonance (NMR), respectively. On-line HPLC/ABTS analysis method with the simultaneous determination of three standard compounds and their radical scavenging activity was established for the quality evaluation of licorices. 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid radicals (ABTS) which is stable and effective was used in replace of DPPH. The radical scavenging activity of three standards is compared with that of Trolox, known as antioxidant, showing a negative peak with a decrease in absorbance at 734 nm for ABTS. This on-line HPLC/ABTS analysis method was validated for specificity, linearity, precision and accuracy in compliance with international conference on harmonization (ICH) guideline.

• Journal of Food Hygiene and Safety
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• v.28 no.4
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• pp.367-375
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• 2013

Kalopanax pictus has pharmacologically anti-inflammatory and analgesic effect and is known to respond to treatment of backache, knee pain and etc. In this study, we investigated the effects on gastric lesions of Kalopanax pictus both from Korea (KPK) and China (KPC) compared with their related origin, Znthoxylum ailanthoide both from Korea (ZAK) and China (ZAC), and Korean Bombax malabaricum (BMK). In preliminary screening, KPK and KPC shown effective inhibition of HCI EtOH-induced gastritis in rats. To elucidate their protective effects on gastric lesions, we assessed inhibition of H. pylori colonization, 2,2-diphenyl-1-picrylhydrazyl(DPPH) radical scavenging activities, reducing power test, and inhibition of lipid peroxidation. KPK was the most effective from antioxidant assays. KPK also shown the inhibition of indomethacin-induced gastric ulcer in rats. Gastric secretion in rats, KPK reduced the secretion of gastric juice and total acidity and raised pH. Therefore, it is possible that KPK can be developed as health functional food and natural medicine. In addition, it can contribute to the standardization with objectivity and reliability for KPK through the criteria establishment of the precise origin of medicine, the prevention of indiscriminate distribution of imitation, and the rising rate of dependence on imports of medicinal herbs, and mixing prevention of low-quality goods.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.10
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• pp.1171-1177
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• 2017

This study evaluated the functional components of barley bran with different particle sizes and cultivars (Dahan, Hinchalssalbori, Heukgwang, Huknuri, and Boseokchal). Barley bran divided into fractions I (<60 mesh), II (60~100 mesh), and III (>100 mesh) was collected as pearling by-products produced by an industrial process consisting of consecutive barley pearlers. Total ${\beta}-glucan$ contents of all cultivars were especially highest in fraction II. Total arabinoxylan was the highest in barley bran from Boseokchal in fraction II. Total polyphenol contents were the highest in bran from Boseokchal and Hinchalssal in fraction II, and contents ranged of 5.61~7.00 and 4.24~6.58, respectively. Total flavonoid contents of all cultivars were especially highest in fraction II. 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities ranged from 2.78~7.53 mg L-ascorbic acid (AA) eq/g and 2.24~4.83 mg AA eq/g, respectively. ABTS and DPPH radical scavenging activities were the highest in barley bran from Dahan in fraction II. In this study, fraction II showed enriched functional components and has the best particle size range for enriched antioxidant activities. These results provide useful data for selection of appropriate cultivars and particle size of bran to achieve high quality barley processing.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.2
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• pp.59-68
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• 2023

Sweet corn is widely consumed due to its high nutritional content and diverse phytochemical composition, including carotenoids and phenolic compounds, which have several benefits for human health. This study aims to identify breeding materials for developing high-functional sweet corn varieties by evaluating the phytochemical and antioxidant activities of 37 Korean sweet corn inbred lines. The results revealed genetic variation in various components, such as carotenoid content (range of 120.7~1239.3 mg 100 g^-1), polyphenol content (490.5~740.6 mg gallic acid equivalent 100 g^-1), and flavonoid content (7.3~68.6 mg catechin equivalent 100 g^-1). In addition, the free radical scavenging capacity, measured using 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid), also varied among the inbred lines. Therefore, in this study, we identified Korean sweet corn inbred lines with high phytochemical content and excellent antioxidant activity. The development of sweet corn varieties with improved functionality is expected to further expand the role of sweet corn as a source of antioxidants in the Korean diet.

• Journal of Nutrition and Health
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• v.54 no.2
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• pp.224-237
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• 2021

Purpose: Paeonia Radix Alba is a traditional herbal medicine used to treat the liver and the spleen. Many studies have reported that Paeonia Radix Alba extract (PR) affects liver injury, but there has been no study on liver injuries induced by thioacetamide (TAA). Therefore, we aimed at evaluating the effect of PR on a TAA-induced acute liver injury (ALI) model. Methods: The antioxidant activity of PR was assayed by the content of total polyphenol, total flavonoid, 1,1-diphenyl-2'-picrylhydrazyl (DPPH), and 2,2'-azino-bis (3-ethylbenzo-thiazoline-6-sulfonicacid) (ABTS) radical scavenging activities in vitro test. ALI was induced via-intraperitoneal injection of TAA (200 mg/kg body weight) for three consecutive days. Also, silymarin (100 mg/kg body weight) and PR (100 or 200 mg/kg body weight) were administered at 1 hours 30 minutes prior to TAA treatment. The levels of ammonia, glutamic oxaloacetic transaminase (GOT), and glutamic pyruvic transaminase (GPT) were analyzed using an assay kit. The expressions of antioxidant proteins including Nrf2, Keap1, HO-1, SOD, catalase, and GPx-1/2 and oxidative stress-related proteins including NOX2, p47^phox, and p22^phox were evaluated by the western blot analysis. Results: PR showed excellent antioxidant activity in vitro. TAA administration increased the levels of ammonia, GOT, and GPT in the ALI control group compared to the normal group, whereas it was significantly reduced by PR pretreatment. Moreover, NADPH oxidase protein expressions were upregulated after TAA treatment, while the elevated expressions were inhibited by PR pretreatment. The expressions of antioxidant protein were downregulated in the ALI control group, whereas Nrf2 activation in the PR group was accompanied by increased levels of antioxidant enzymes. Conclusion: PR administration increased the antioxidant enzymes via activation of the Keap1/Nrf2 pathway and inhibited the protein levels of NADPH oxidase factors. Taken together, these results showed that PR treatment may be considered to ameliorate acute liver injury induced by TAA.

• Korean Journal of Food Science and Technology
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• v.40 no.1
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• pp.21-30
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• 2008

In this study, the antioxidant activities of 27 medicinal herbs and plants were measured. The dried medicinal herbs and plants were pulverized and extracted by water, 15% ethanol, and 45% ethanol, respectively at above $80^{circ}C$ for 90 minutes. The original and diluted extracts were tested for their antioxidant activities by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging activity assay. Cornus officinalis (C) and Scutellaria baicalensis (S) were selected to develop rice wines with higher antioxidant activities, based on the result of the 45% ethanol extraction. The rice wine developed using sample showed the highest antioxidant activity as comparing to those of other commercial rice wines. The rice wine samples were analyzed for titratable acidity, pH, $^{\circ}Brix$, reducing sugar content, color (L, a, b), amino-acidity, and ultraviolet absorption. The preferences for color, aroma, and overall acceptability were determined using a 9-point hedonic scale by 150 consumers. The sweetness, sourness, fruitiness, color, and medicinal herb-taste levels of the developed rice wines were also evaluated, using a 9-point just-about-right scale. The mean overall acceptability score of c (5.54) was higher than that of sample S. Based on the results, the sourness and medicinal herb-taste levels of sample s should be modified to higher levels, and the fruitiness of sample S also needs to be adjusted. For a future study, the final compositions of the developed rice wines will be adjusted for product launching based on the preference test data acquired in this study.

• Korean Journal of Food Science and Technology
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• v.45 no.2
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• pp.174-179
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• 2013

Three low-molecular compounds were isolated from methanol extracts of pear (Pyrus pyrifolia N. cv. Chuhwangbae) fruit peels using solvent fractionation, various types of column chromatogrphy (Diaion HP-20, Sephadex LH-20, and silica gel), and high performance liquid chromatography with an assay guided by 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activity. The isolated compounds were identified as 2-carboxyl-4(1H)-quinolinone (kynurenic acid, 1) from butanol fraction, cis-p-coumaric acid (2) from ethyl acetate-acidic fraction, and vanillin (3) from the ethyl acetate-phenolic fraction, respectively. These isolated compounds were confirmed on the basis of the spectroscopic data of electrospray ionization mass spectrometry and nuclear magnetic resonance. This is the first time that compounds 1-3 were isolated and identified in pear.