• Journal of Korean Society of Environmental Engineers
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• v.22 no.4
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• pp.765-773
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• 2000

The degradation of humic acid using $TiO_2$ coatings was studied, $TiO_2$ coatings were prepared by dip-coating method. Sol solutions for coating were prepared by mixing the gel, which can be produced by the reaction of $TiOCl_2$ and $NH_4OH$ solution, and hydrogen peroxide solution, and hydrolysis of titanium tetraisopropoxide (TTIP). It was shown from XRD that coatings from sol aged at $100^{\circ}C$ for 18h with titanium peroxo solution were crystallized to anatase in the range of temperatures of $25^{\circ}C$ to $500^{\circ}C$. In contrast, those coated from TTIP were crystallized to anatase at temperature above $400^{\circ}C$. So the sols originated from $TiCl_4$ can be applied for not only on the heat-resistance substrates but on the plastic substrates. Thickness and the quality of the films were dependent on the withdrawing speed, the concentration of sol, and the number of coating. The films showed various interference colors depending on the thickness of them. In the case that the films coated 2 times at withdrawing speed of 2.5cm per minute by 0.2M sol, the films had a transparent light blue color with thickness of around 50nm. It was known from the result of photo-degradation by $TiO_2$ coatings using humic acid that the removal efficiency of $COD_{cr}$ was over 85% after illumination of $UV/H_2O_2$ for 40min. and that of UV/VIS absorbable materials was over 95%.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.5
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• pp.373-382
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• 1984

Processing conditions of retort pouched fried mackerel fish meat paste and quality stability during storage were investigated. The reasonable amounts of added ingredients to the frozen mackerel meat paste were $10\%$ of corn starch, $1\%$ of soybean protein, $1.5\%$ of sodium chloride, $0.6\%$ of monosodium glutamate, $0.3\%$ of alcoholic extract of red pepper, and $0.1\%$ of sodium erythorbate as an antioxidant and also added water corresponding to $10\%$ of the frozen mackerel meat paste. After grinding the defrosted mackerel fish meat paste with ingredients, the meat paste was molded in bar type and fried in soybean oil at $170-180^{\circ}C$ for 3 minutes. The fried mackerel meat paste was cooled, vacuum-packed in laminated plastic film bag (polyester/polyvinylidene chloride/unoriented polypropylene : $12{\mu}m/15{\mu}/50{\mu}m,\;14{\times}19cm$) and finally sterilized at $120^{\circ}C$ for 20 minutes in a hot water circulating retort. The pH, volatile basic nitrogen, moisture content, water activity, color, thiobarbituric acid value, peroxide value, texture and viable bacterial count of products were examined during 100 days of storage at $25{\pm}3^{\circ}C\;and\;5^{\circ}C$. The results showed that products could be preserved in good condition for 100 days at $25{\pm}3^{\circ}C$. Judging from sensory evaluation, the quality of products was not inferior to that of market products.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.8
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• pp.979-984
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• 2006

Although iron is essential for many physiological processes, excess iron can lead to tissue damage by promoting the generation of reactive oxygen species (ROS). There is increasing evidence that ROS might play an important role in the pathogenesis of cardiovascular disease. However, the effects of iron excess on platelet function and the thrombotic response to vascular injury are not well understood. We examined the effects of iron excess-induced oxidative stress and the antioxidants on platelet aggregation. Oxidative stress was accessed by either free iron $(Fe^{+2})$ or hydrogen peroxide $(H_2O_2)$, as well as their combination on washed rabbit platelets (WPs) in vitro. When WPs were stimulated with either $Fe^{+2}$ alone or a subthreshold concentration of collagen, which gave an aggregatory curve with a little effect, and a dose dependent increase in platelet aggregation was observed by increasing concentrations of $Fe^{+2}$ with $H_2O_2$. This aggregation was associated with the iron-catalyzed formation of hydroxyl radicals from $H_2O_2$, and were inhibited by NAD/NADP (proton acceptor), catalase $(H_2O_2\;scavenger)$, tiron (iron chelator), mannitol (hydroxyl radical scavenger), and indomethacin (cyclooxygenase inhibitor), but not by NADH/NADPH (proton donor), superoxide mutase, and aspirin. However, NADH/NADPH, an essential cofactor for the antioxidant capacity by the supply of reducing potentials, showed the effect of an enhanced radical formation, suggesting a role for NADH/NADPH-dependent oxidase. These results suggest that iron $(Fe^{+2})$ can directly interact with washed rabbit platelets and this aggregation be mediated by OH formation as in the Fenton reaction, inhibited by radical scavengers.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.10
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• pp.1271-1278
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• 2007

In this study, the ability of Styela clava or Styela plicata to reduce ethanol-induced hepatotoxicity and hepatic and leucocytic DNA damages was evaluated. Twenty four male SD rats were given 25% ethanol containing water (ad lib, p.o.) and divided into 3 groups; ethanol treated control group (EtOH), ethano1+3% S. clava (EtOH+SC), and ethano1+3% S. plicata (EtOH+SP). After 6 weeks, the supplementation of S. clava reduced the plasma ALT, ALP and LDH activities significantly (p<0.05), while S. plicata induced significant decrease in the plasma LDH activity only. The comet assay was employed to quantify the alcohol-induced DNA damage in rat hepatocytes and leucocytes. A significant protective effect on hepatic and leucocytic DNA damages was observed in S. clava or S. plicata supplemented groups compared to the EtOH control group. The hepatic DNA damage was correlated positively with plasma ALP and LDH activities. These results demonstrated that S. clava or S. plicata supplementation protected alcohol-induced hepatic and leucocytic DNA damage.

• Korean journal of food and cookery science
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• v.14 no.1
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• pp.84-90
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• 1998

A research was carried out to determine the formation, contents in foods, and antioxidative effects of conjugated linoleic acid (CLA). CLA was known as a mixture of positional isomer of linoleic acid (LA), that was included in milk, meat, and fish. The formation of CLA from methyl linoleate and soybean oil (SBO) storecd at 20${\pm}$1$^{\circ}C$ was higher than at 40${\pm}$1$^{\circ}C$, and CLA formation from methyl linoleate stored at 20${\pm}$1$^{\circ}C$ was over 13 times higher than early amounts(188 ppm) and was higher than that from SBO. In edible vegetable oils, the content of CLA were the highest in canola oil (CAO, 348 ppm) but were decreased during storage at 40${\pm}$1$^{\circ}C$, while the content of CLA in cotton seed oil (CSO) were 292 ppm, which increased dramatically (1322 ppm) during 28 days of storage at 40${\pm}$1$^{\circ}C$. Because the peroxide value (POV) of CSO at that time was very low (10.05 meq/kg $.$ oil), CLA occurrence of CSO was shown to be very available during storage at temperature. CLA content of milk from a market ranged 293∼2148 ppm, which depended on the manufacturing, companies. In meat, the CLA content was very high in pork (2379 ppm), and among fishes, that of spanish mackerel was the highest (1040 ppm, almost same as beef, which increased greatly (2039 ppm) during boiling with seasoning. Antioxidative effect of CLA on SBO was almost same as that of BHT until 7 days of storage at 40${\pm}$1$^{\circ}C$, but decreased greatly after that period. In case of com oil (CNO), antioxidative effects of CLA were higher than those or BHN and tocopherol, suggesting that the effect was different depending on the kinds of oils used as substrates. During heating at 180${\pm}$1$^{\circ}C$, antioxidative effect of CLA on SBO appeared almost same as those or BHT and tocopherol, and it was also shown greater effects in heating at high temperature (180${\pm}$1$^{\circ}C$) than at low temperature(40${\pm}$1$^{\circ}C$).

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.4
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• pp.435-441
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• 2017

The present study was carried out to evaluate the applicability of Tenebrio molitor larvae (mealworm) as a health functional food material in order to contribute to the development of the domestic insect industry and health functional food industry. Protein hydrolysates were prepared from mealworm powder by enzymatic hydrolysis using five different proteases (alcalase, bromelain, flavourzyme, neutrase, and papain), and the hydrolysates were then tested for their antioxidant activities. Based on available amino group contents and sodium dodecyl sulphate-polyacrylamide gel electrophoresis analyses, mealworms treated with alcalase ($4,781.39{\mu}g/mL$), flavourzyme ($5,429.35{\mu}g/mL$), or neutrase ($3,155.55{\mu}g/mL$) for 24 h showed high degree of hydrolysis (HD) value, whereas HD values of bromelain ($1,800{\mu}g/mL$) and papain-treated ($1,782.61{\mu}g/mL$) mealworms were much lower. Protein hydrolysates showing high HD values were further separated into > 3 kDa and ${\leq}3kDa$ fractions by a centrifugal filter system and then lyophilized, and the production yields of the low molecular weight protein hydrolysates (${\leq}3kDa$) by alcalase, flavourzyme, and neutrase were 42.05%, 26.27%, and 30.01%, respectively. According to the RC_{50} values of the protein hydrolysates (${\leq}3kDa$) obtained from three different antioxidant analyses, all three hydrolysates showed similar antioxidant activities. Thus, alcalase hydrolysates showing the highest production yield of low molecular weight protein hydrolysates were further tested for their inhibitory effects on peroxidation of linoleic acid by measuring thiobarbituric acid values, and the results show that peroxidation of untreated linoleic acid increased dramatically during 6 days of incubation. However, pretreatment with the hydrolysates ($100{\sim}800{\mu}g/mL$) significantly inhibited linoleic acid peroxidation in a dose-dependent manner over 6 days.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.5
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• pp.545-551
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• 2017

Curcuma longa L. (CL) is widely used as a spice and coloring agent in several foods, such as curry and mustard, as well as cosmetics and drugs. In this study, we investigated the protective effects of CL extracted with various solvents [methanol (MC), ethanol (EC), acetone (AC)] on $H_2O_2-induced$ DNA damage in human leukocytes along with total polyphenol contents (TPC) and antioxidant properties. The antioxidant effects of CL were determined by measuring 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity (RSA) and superoxide dismutase (SOD)-like activity. The preventive effect of CL on oxidative stress-induced DNA damage and DNA repair capacities were assessed using comet assay. MC showed the highest TPC (11.17 g gallic acid equivalents/100 g) and antioxidant properties among the solvent extracts. The $SC_{50}$ for DPPH RSA was MC: 35.0 > AC: 45.8 > EC: $57.8{\mu}g/mL$ and SOD-like activity was MC: 46.6 > EC: 141.5 > AC: $296.4{\mu}g/mL$. In the comet assay, the $ED_{50}$ value of MC showed the highest inhibition ($86.7{\mu}g/mL$) of $H_2O_2-induced$ DNA damage, followed by AC ($110.0{\mu}g/mL$) > EC ($115.8{\mu}g/mL$). Analysis of the percentage of damaged cells showed that repair capacity significantly decreased at 4, 8, and 12 h from $H_2O_2-induced$ oxidative stress in each extract. After 12 h, level of DNA damage recovery was similar to the negative control level. These results suggest that CL has potential antioxidant activity and a protective effect against oxidation-induced DNA damage, and the methanol extract of CL was the most effective.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.10
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• pp.1164-1170
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• 2017

Protaetia brevitarsis larvae (PBL) has recently been registered as a temporary food in Korea, and this study evaluated the application potential of PBL proteins as health functional food materials. Protein hydrolysates were prepared from PBL powder by enzymatic hydrolysis using five different proteases (alcalase, bromelain, flavourzyme, neutrase, and papain), and based on the results from the peptide content and SDS-PAGE analyses, PBL treated with alcalase or flavourzyme showed a high degree of hydrolysis (HD) value, whereas the HD value of those treated with neutrase, bromelain, or papain was minimal. The protein hydrolysates showing a high HD value were separated further into the fractions of >3 kDa and <3 kDa by a centrifugal filter system and then lyophilized, and according to the $RC_{50}$ values of the protein hydrolysates (<3 kDa) obtained from three different antioxidant analyses; the alcalase hydrolysates showed the highest antioxidant activity. Therefore, the alcalase hydrolysates were tested further for their inhibitory effects on the peroxidation of linoleic acid by measuring the thiobarbituric acid values. The results showed that the peroxidation of untreated linoleic acid increased dramatically during 6 days of incubation, but a pretreatment with the hydrolysates ($100{\sim}800{\mu}g/mL$) significantly inhibited the linoleic acid peroxidation in a dose-dependent manner for 6 days. Our current studies are focused on the identification of active peptide sequences from alcalase hydrolysates.

• Tuberculosis and Respiratory Diseases
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• v.41 no.3
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• pp.215-221
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• 1994

Background: It is well known that oxygen free radicals(OFR) play a vital role in the various type of acute lung injury. Among various antioxidant defense mechanisms, the superoxide dismutases(SOD) are thought to be the first line of antioxidant defense by catalyzing the dismutation of two superoxide radicals to yield hydrogen peroxide and oxygen. Eukaryotic cells contain two types of intracellular SOD : cytosolic, dimeric copper/zinc- containing enzyme(CuZnSOD) and mitochondrial, tetrameric manganese-containing enzyme(MnSOD). The purpose of this study is to evaluate the time-dependent gene expression of MnSOD and CuZnSOD in the endotoxin-treated rats, and to compare with the manifestations of LPS-induced acute lung injury in rats. Methods: Total RNA from rat lung was isolated using single step phenol extraction 0, 1, 2, 4, 6, 12, 18, 24 hours after E. coli endotoxin injection(n=3, respectively). RNA was separated by formaldehyde-containing 1.2% agarose gels elctrophoresis, transblotted, baked, prehybridized, and hybridized with $^{32}P$-labeled cDNA probes for rat MnSOD and CuZnSOD, which were kindly donated by Dr. Ho(Duke University, Durham, NC, USA). The probes were labeled by nick translation. Blots were washed and autoradiography were quantitated using laser densitometry. Equivalent amounts of total RNA/gel were assessed by monitoring 28S and 18S rRNA. Results: Endotoxin caused a rise in steady-state MnSOD mRNA levels by 4h with peak mRNA accumulation by 6h. Continued MnSOD mRNA expression was observed at 12h. CuZnSOD mRNA expression was observed from 1h to 24h with peak levels by 18h. Conclusion: These results suggest that SOD palys an important defensive role in the endotoxin-induced acute lung injury in rats.

• Tuberculosis and Respiratory Diseases
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• v.41 no.3
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• pp.222-230
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• 1994

Background: Paraquat, a widely used herbicide, is extremely toxic, causing multiple organ failure in humans. Paraquat especially leads to irreversible progressive pulmonary fibrosis, which is related to oxygen free radicals. However, its biochemical mechanism is not clear. Natural mechanisms that prevent damage from oxygen free radicals include changes in glutathione level, G6PDH, superoxide dismutase(SOD), catalase, and glutathione peroxidase. The authors think catalase is closely related to paraquat toxicity in the lungs Method: The effects of 3-amino-1,2,4-triazole(aminotriazole), a catalase inhibitor, on mice administered with paraquat were investigated. We studied the effects of aminotriazole on the survival of mice administered with paraquat, by comparing life spans between the group to which paraquat had been administered and the group to which a combination of paraquat and aminotriazole had been administered. We measured glutathion level, glucose 6-phosphate dehydrogenase(G6PDH), superoxide dismutase(SOD), catalase, and glutathione peroxidase(GPx) in the lung tissue of 4 groups of mice: the control group, group A(aminotriazole injected), group B(paraquat administered), group C(paraquat and aminotriazole administered). Results: The mortality of mice administered with paraquat which were treated with aminotriazole was significantly increased compared with those of mice not treated with aminotriazole. Glutathione level in group B was decreased by 20%, a significant decrease compared with the control group. However, this level was not changed by the administration of aminotriazole(group C). The activity of G6PDH in all groups was not significantly changed compared with the control group. The activities of SOD, catalase, and glutathione peroxidase(GPx) in the lung tissue were significantly decreased by paraquat administration(group B); catalase showed the largest decrease. Catalase and GPX were significantly decreased by aminotriazole treatment in mice administered with paraquat but change in SOD activity was not significant(group C). Conclusion: Decrease in catalase activity by paraquat suggests that paraquat toxicity in the lungs is closely related to catalase activity. Paraquat toxicity in mice is enhanced by aminotriazole administration, and its result is related to the decrease of catalase activity rather than glutathione level in the lungs. Production of hydroxyl radicals, the most reactive oxygen metabolite, is accelerated due to increased hydrogen peroxide by catalase inhibition and the lung damage probably results from nonspecific tissue injury of hydroxyl radicals.