• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.3
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• pp.198-204
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• 1988

This study was aimed at obtaining elementary data on enzymatic browning of potato and potato products and examining the inhibitory method of browning. Therefore, we extracted polyphenol oxidase from potatoes(Solanum tubersum L.), and investigates its general properties and inhibiting effects of its activity with the different concentrations of sulfites($Na_2S_2O_4,\;Na_2SO_3{\cdot}7H_2O,\;NaHSO_3$). The optimum pH and temperature of polyphenol oxidase were observed to be 6.5 and $37^{\circ}C$ respectively. The polyphenol oxidase at PH5 was very stable, and the activity of polyphenol oxidase between pH $5.0{\sim}9.0$ was estimated to be relatively high, showing $72{\sim}75%$ of its activity at pH5. The polyphenol oxidase was very stable when heated at $40^{\circ}C$ for one hour, and almost 50% of enzyme activity was decreased when heated at $70^{\circ}C$ for twelve minutes. At 0.1mM concentrating of sulfites the relative activity of polyphenol oxidase was 98% in all the three cases of sulfites. Thus sulfites at 0.1mM concentration was found to have little inhibiting effect on polyphenol oxidase activity. At 1mM concentration of sulfites $NaHSO_3$ showed the lowest 36% relative activity among the three. At 5mM concentration of sulfites, the relative activity of $Na_2SO_3{\cdot}7H_2O$ was the lowest 14%.

• Food Science and Preservation
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• v.24 no.1
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• pp.125-133
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• 2017

This study evaluated the changes of physiochemical properties, phytochemical contents, and biological activities during the vinegar fermentation of Elaeagnus multiflora fruit. The contents of pH and reducing sugar decreased from 3.55 and 6.88 mg/mL 3.34 and 2.13 mg/mL, respectively. However the acidity increased from 0.48% to 5.48% during the vinegar fermentation. The alcohol contents increased up to a maximum value of 6.6% at 20 days, and it then decreased at the end fermentation days (2.0%). The viable numbers of acetic acid bacteria and yeasts increased from 4.32 log CFU/mL and 3.23 log CFU/mL at 10 days to 5.4 log CFU/mL and 5.5 log CFU/mL during the spontaneous fermentation, respectively. The major organic acids were acetic acid (38.84 mg/mL), lactic acid (4.92 mg/mL), and malic acid (1.51 mg/mL). The soluble phenolic and flavonoid contents increased from 0.79 mg/mL and 0.12 mg/mL of initial fermentation day to 1.22 mg/mL and 0.14 mg/mL during the spontaneous fermentation. Content of epicatechin gallate decreased from $168.1{\mu}g/mL$ at 10 days to $115.97{\mu}g/mL$. However the content of gallic acid increased from $18.52{\mu}g/mL$ to $95.07{\mu}g/mL$ during fermentation. After 60 days of the fermentation, the antioxidant and digestive enzyme inhibitory activities were 71.35% (DPPH), 79.27% (ABTS), 68.72% (${\cdot}OH$), 85.42% (${\alpha}$-glucosidase), 52.12% (${\alpha}$-amylase), and 53.66% (pancreatic lipase), respectively.

• Current Research on Agriculture and Life Sciences
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• v.4
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• pp.55-64
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• 1986

Polyphenol oxidase in japanese pear (Pyrus communis var. mansamkil) was isolated, partially purified and its some properties were investigated. Polyacrylamide disc gel electrophoresis indicated two bands with polyphenol oxidase activity in the extract from acetone dry powder of par flesh. These two polyphenol oxidases (PPO A and PPO B) were purified through acetone precipitation and diethylaminoethyl cellulose column chromatography. PPO A and B were purified 7.8 fold and 8.7 fold by the present procedure, respectively. The Rm values of partially purified PPO A and B were estimated to be 0.58 and 0.68, respectively. The optimum temp, and pH of PPO A activity were $33^{\circ}C$ and pH 7.0, while those of PPO B were $30^{\circ}C$ and pH 4.2, respectively. Two PPO were unstable over the temperature of $60^{\circ}C$. The substrate specificity of pear PPO showed high affinity toward o-diphenolic compounds, especially catechol in PPO A and chlorogenic acid in PPO B, but inactive toward m-diphenol, p-diphenol and monophenols. PPO A showed affinity toward the trihydroxyphenolic compound. $Zn^{{+}{+}}$ activated the PPO A activity but $Fe^{{+}{+}}$ inhibited PPO B activity, while $Fe^{{+}{+}}$ and $Zn^{{+}{+}}$ activated the PPO B activity, while $Fe^{{+}{+}}$ and $Zn^{{+}{+}}$ activated the PPO B activity but $K^+$, $Mg^{{+}{+}}$, $Ca^{{+}{+}}$ and $Hg^{{+}{+}}$ inhibited at 10mM concentration. $Cu^{{+}{+}}$ activated the enzyme action at low concentrations but inhibited at high concentration. Inhibition studies indicated that L-ascorbic acid, L-cysteine and thiourea were most potent. The Km values of PPO A and PPO B for catechol were 20mM and 14.3mM, respectively.

• Food Science and Preservation
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• v.19 no.6
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• pp.858-865
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• 2012

In this research, the soaking and steaming conditions of Korean wheat meju according to the degree of milling were investigated, and the quality characteristic was analyzed, for the manufacture of the standardized Korean wheat meju. As a result of the changes in weight, volume, moisture content, and moisture absorption amount, which indicate the physical properties of Korean wheat meju using 20% polished wheat, 50% polished wheat, whole wheat, and whole wheat flour, most of the wheat materials reached the equilibrium state after 4 hours of soaking. Also, the appropriate steaming time to complete the cooking of the wheat materials was found to be 10 min at $100^{\circ}C$, except for whole wheat. The 20 and 50% polished wheat materials were selected for Korean wheat meju based on the soaking and steaming results. The selected wheat materials were fermented using Aspergillus oryzae and Bacillus subtilis M1, respectively, and the quality properties and enzyme activities showed that A. oryzae would be effective for the manufacture of Korean wheat meju. Also, the 50% polished wheat showed higher total sugar content, reducing sugar content, and ${\alpha}$-amylase activity than the 20% polished wheat. Therefore, it is supposed that the fermentation of 50% polished wheat by A. oryzae would be appropriate for manufacturing superior Korean wheat meju.

• Journal of Life Science
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• v.29 no.3
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• pp.345-353
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• 2019

This study investigated the physiochemical properties, the anti-oxidant and alcohol metabolism enzyme activities, and the anti-inflammatory effects of three muskmelon vinegars prepared under different fermentation conditions, namely MV-1, MV-2, and MV-3. The total acidity of each vinegar was 4.00%, 4.32%, and 4.35%, respectively. Organic acid analysis showed that malic acid (58.37 mg/ml) was the most prevalent in MV-1 and that acetic acid was most prevalent in both MV-2 (46.95 mg/ml) and MV-3 (66.70 mg/ml). The total phenolic content of the muskmelon vinegars was highest at $129.74{\mu}g$ tannic acid equivalents (TAE)/ml in MV-3. The DPPH radical scavenging activity of the vinegars increased in a dose-dependent manner (p<0.05) and was 89.28% at MV-3 40% concentration. Similarly, SOD activitity increased in a concentration-dependent manner (p<0.05) so that levels for MV-1, MV-2, and MV-3 at 60% concentrations were 40.84%, 52.17% and 72.55%, respectively (p<0.05). Moreover, the ADH and ALDH activities of muskmelon vinegar were seen to increase in a concentration-dependent manner; ADH activity at 60% concentration was highest at 136.58% in MV-1 and ALDH activity at 60% concentration was highest at 100.25% in MV-2. The nitrite scavenging activities of MV-1, MV-2, and MV-3 at pH 1.2 were found to be 81.58%, 94.72%, and 87.75%, respectively. Anti-inflammatory effects were also examined, using LPS-stimulated RAW 264.7 cells, and nitric oxide production was reduced to 25.93%, 10.01%, and 79.75% by addition of MV-1, MV-2, and MV-3 at 1% concentration, respectively (p<0.05). These results suggest that the MV-3 muskmelon vinegar has great potential as an ingredient for high quality functional health beverages.

• Journal of Food Hygiene and Safety
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• v.38 no.6
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• pp.517-527
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• 2023

This study aimed to examine the possibility of upcycling extracts of Angelica keiskei and Oenanthe javanica juice by-products through comparing enzyme extraction (EE) and complex extraction (CE) methods to increase the extraction yield and flavor of materials. A higher extraction yield was obtained for free amino acid content with EE and CE for A. keiskei and O. javanica juice by-products, respectively, and a higher extraction efficiency was achieved with juice by-products than with extracts prepared from raw materials before juice production. The content of major amino acids varied depending on the extraction method used. When used according to the characteristics of the extract, their use as a functional material was confirmed along with improvement in the flavor of the food. Consistently high extraction yields for organic acid and sugar levels were obtained with CE in A. keiskei and O. javanica juice by-products. The DPPH radical scavenging ability and TPC were consistently high with CE in A. keiskei and O. javanica juice by-products; the increase in extracted content was likely because of the reaction between the ethanol used for CE and the phenolic compounds. However, because the antioxidant capacity of the juice by-product extracts was somewhat lower than that of the extracts from raw materials before juice production, the amount used should be reviewed. The TFC was found to be higher in extracts obtained with EE than with CE for A. keiskei juice by-products; however, no significant difference was observed between EE and CE in the O. javanica juice by-products. Through this study, the taste compounds and antioxidant properties of extracts obtained from juice by-products produced after the production of A. keiskei and O. javanica green juice were analyzed, and the availability of high value-added materials was confirmed. Based on these research results, expanding specific R&D for practical use should be explored.

• Food Science and Preservation
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• v.31 no.1
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• pp.149-160
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• 2024

Dextran is a glucose homo-polysaccharide with a predominantly α-1,6 glycosidic linkage of microbial source and is known to be produced primarily by lactic acid bacteria. However, it can also be obtained through the dextran dextrinase of acetic acid bacteria (Gluconobacter oxydans). The dextrin-based dextran was obtained from rice starch using G. oxydans fermentation of rice hydrolysate, and its properties were studied. Both dextrin- and rice hydrolysate-added media maintained the OD value of 6 after 20 h of incubation with acetic acid bacteria, and the gel permeation chromatography (GPC) analysis of the supernatant after 72 h of incubation confirmed that a polymeric material with DP of 480 and 405, which was different from the composition of the substrate in the medium, was produced. The glucose linkage pattern of the polysaccharide was confirmed using the proton nuclear magnetic resonance (¹H-NMR) and the increased α-1,4:α-1,6 bond ratio from 0.23 and 0.13 to 1:2.37 and 1:4.4, respectively, indicating that the main bonds were converted to α-1,6 bonds. The treatment of dextrin with a rat-derived alpha-glucosidase digestive enzyme resulted in a slow release of glucose, suggesting that rice hydrolysate can be converted to dextran using acetic acid bacteria with glycosyltransferase activity to produce high-value bio-materials with slowly digestible properties.

• Applied Microscopy
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• v.39 no.4
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• pp.311-317
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• 2009

This study was performed using animals to confirm the effect of tourmaline-ionized water (TIW) the properties of which were changed by tourmaline energy and electric discharge. In the ICR mice fed high-fat diet, body weight increasing rate of the TIW-treated group (Exp) was generally decreased and moreover exhibited significance at 11th week (P<0.05) compared with the control (Con) group fed distilled water, although water intake of the Exp group was lower than that of the Con group. In the ICR mice with $CCl_4$-induced hepatotoxicity, AST and ALT activities of the Exp group were not significant but showed some decreasing trend, and histological damage of liver was less compared with thatof the Con group. On the study of ethanol-induced hangovers in Sprague-Dawley rat, blood alcohol concentration was significantly decreased (P<0.01), activity of GST, antioxidant enzyme related to the alcohol metabolism, was increased in liver tissue (P<0.05), and AST and ALT show a tendency to be decreasedin the Exp group. These results suggest that drinking TIWhas not only some obesity preventing effect but also an alcohol detoxification effect and liver protecting effect in vivo. It is supposed due to a structural change of water cluster and a property which maintains the changed structure through tourmaline energy and electric discharge. Therefore, TIW has a potentiality to be developed as functional water with several beneficial effects as well as for daily drinking, but further study on the mechanism related with efficacy will be necessary.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.12
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• pp.1727-1734
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• 2005

The fermentation characteristics and mono- and di-saccharides compositions during the early stage of ensiling were studied with a temperate grass, Italian ryegrass (Lolium multiflorum Lam.) and a tropical grass, guineagrass (Panicum maximum Jacq.). The laboratory silos were kept in the room set at 25$^{\circ}C$, and then were opened on 0.5, 1, 2, 3, 5 and 7 days (14 days in Italian ryegrass) after ensiling, respectively. The Italian ryegrass silage showed a fast and large pH decrease caused by a fast and large production of lactic acid during the first 5 days of ensiling and succeeded to achieve lactic acid type fermentation; high lactic acid/acetic acid and lactic acid content at the end of ensiling (14 days), low values of pH (3.74), acetic acid, ethanol and ammonia-N/total nitrogen, none or only small amounts of Butyric acid, valeric acid and propionic acid. The guineagrass silage showed a slow decrease in pH and a slow increase in lactic acid content during the full ensiling period, causing a high final pH value, low contents of lactic acid, acetic acid, total volatile fatty acids and total organic acids. In Italian ryegrass silage, mono- and di-saccharides compositions decreased largely within the initial 0.5 day (12 h) of ensiling. Sucrose disappeared rapidly within the initial 0.5 day of ensiling, but fructose and glucose contents showed an initial rise by the activity of enzymes in plant tissues, and then decreased gradually. On the other hand, the contents of monoand di-saccharides in guineagrass showed the largest decreases due mainly to plant respiration within the initial 0.5 day of ensiling, and no initial rises in fructose and glucose contents during the early stage of ensiling because of the absence of fructans which are hydrolyzed into fructose and glucose in temperate grasses. In both silages, the rate of reduction in mono- and di-saccharides compositions within the initial 5 days of ensiling was ranked in the order of glucose>fructose>sucrose, suggesting that glucose and fructose might be more favorably utilized than sucrose by microorganisms and glucose is the first fermentation substrate. It was concluded that the silage made from Italian ryegrass with high moisture content had a good fermentation quality owing to the dominance of lactic acid bacteria and active lactic acid fermentation during the initial stage of ensiling. These results can be explained by rapid plant sap liberation and the high activity of plant enzyme hydrolyzed fructans into fructose and glucose within the initial 2 days of ensiling, which stimulate the homofermentative lactic acid bacteria growth. In ensiling a temperate grass, the physical characteristics may ensure the rapid onset of fermentation phase, which results from the smaller losses of water-soluble carbohydrates during the initial stage of ensiling and providing sufficient water-soluble carbohydrates for lactic acid bacteria. The silage made from guineagrass with intermediate dry matter and high initial mono- and di-saccharides content was stable silage. This could be explained by the higher incorporation of air during the very early stage of ensiling and the restriction of cell breakdown and juice release due to the properties of a tropical grass with coarse porosity and stemmy structures. These physical characteristics delayed the onset of lactic acid bacteria fermentation phase by extending the phases of respiration and aerobic microorganisms activity, causing the higher loss of water-soluble carbohydrates and the shortage of lactic acid bacteria fermentation substrates.

• The Journal of Dong Guk Oriental Medicine
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• v.9
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• pp.179-191
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• 2000

Anti-bone resorption properties of the Korean herbal medicine, CEDR, which is comprised 5 herbs of [Drynariae Rhizoma, Loranthi Ramus, Cibotii Rhizoma, Amydae carapax, Psoraleae semen], were investigated. Mouse calvarial osteoblast cells were isolated and cultured. Mouse osteoblasts, which were stimulated by PTH, $1,25(OH)_2D_3$, $TNF-\alpha$ and IL-1 as bone resorption agents, showed increased collagenolysis by producing the active gelatinase. IL-1 in stimulating bone resorption was examined using fetal mouse long bone organ culture. IL-1 stimulated bone resorption and produced marked resorption when present simultaneously. The results of in vitro cytotoxicities showed that CEDR extracts have no any cytotoxicities in concentrations of $1-60{\mu}g/ml$ and furthermore there is no any cytotoxicity even in concentration of $120{\mu}g/ml$ on mouse calvarial bone cells. CEDR extracts had protective activity against PTH (5 units/ml, or $IL-1{\alpha}$ (1 ng/ml) or $TNF-\alpha$ or $1,25(OH)_2D_3$ (20 ng/ml), $IL-1{\alpha}$ and $IL-1{\beta}-induced$ collagenolysis in the mouse calvarial cells. Pretreatment of the CEDR extracts for 1 h, which by itself had little effect on cell survival, did not enhance the collagenolysis, nor significantly reduced the collagenolysis by pretreatment. Furthermore, the medicinal extracts were shown to have the protective effects against collagenolysis induced by $IL-1{\alpha}$ and $IL-1{\beta}$. Pretreatment of the extracts for 1 h significantly reduced the collagenolysis. Interestingly, the CEDR extracts were shown to have the inhibiting effects against gelatinase enzyme and processing activity induced by the bone resorption agents of PTH, $1,25(OH)_2D_3$, $TNF-\alpha$, $IL-1{\beta}$ and $IL-1{\alpha}$ with strong protective effect in pretreatment with the extracts. CEDR extracts were shown to have the inhibiting effects against $IL-1{\alpha}-$ and $IL-1{\beta}-stimulated$ bone resorption and the effect of the pretreatment with a various concentrations of the medicinal extracts were significant. These results indicated that the CEDR extracts are highly stable and applicable to clinical uses in osteoporosis.