• Korean Journal of Food Science and Technology
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• 제33권5호
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• pp.534-539
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• 2001

To utilize oyster cannery processing waste water effectively, this study was carried out to prepare instant powdered soup using oyster wash water. Instant powdered soup from oyster hot-water extracts (HWE) was prepared by mixing oyster spray-dried hot-water extracts (15 g) with table salt (5 g), cream powder (19 g), milk replacer (12 g), wheat flour (20 g), corn flour (15 g), starch (5 g), glucose (7.5 g) and onion powder (1.5 g). In preparing instant powdered soup from oyster wash water (OWW), powder from oyster spray-dried wash water instead of the spray-dried hot water extracts, was added and other additives were added in proportion to those in the HWE. The OWW consists mainly of carbohydrates (71.1%). It was not different from the instant powdered soup from hot-water extracts. The volatile basic nitrogen, vaible cell counts, coliform group of instant powdered soup from oyster wash water contains 29.4 mg/100g, $4.6{\times}10^4\;CFU/g$, <18 MPN/100g, respectively and its water activity has 0.246. So it was a hygienically safe and conservable instant food. The main fatty acid of OWW was 16 : 0 and 18 : 1n-9. Its chemical score of protein was 59.4% and its main inorganic matter was iron. According to a sensory evaluation, in contrast to the HWE, the OWW had a slightly lower aroma but better taste. It was concluded from the above chemical and sensual evaluation that the oyster wash water can be used as a flavor enhancer for instant powdered soup.

• Korean Journal of Fisheries and Aquatic Sciences
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• 제52권5호
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• pp.452-460
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• 2019

Exposure to heavy metals through the consumption of contaminated seafood poses a health risk to humans. In Korea, seafood imports are increasing with consumption, with the largest increase in imported seafood coming from Russia. Peter the Great Bay and the Razdolnaya River are both major fisheries and protected areas under the Northwest Pacific Action Plan located near Vladivostok, Russia. This study analyzed heavy metal [cadmium (Cd), lead (Pb), total mercury (tHg), and total (tAs), and inorganic (iAs) arsenic] concentrations in shellfish and crustaceans collected from these areas. Except for iAs, the major toxic heavy metal concentrations of the samples met the national standards (Cd, 0.024-0.982 and 0.003-0.379 mg/kg; Pb, 0.021-1.533 and 0.002 mg/kg; tHg, 0.006-0.015 and 0.036-0.097 mg/kg). The tAs concentrations of three samples exceeded the Russian standard (5 mg/kg, wet weight), whereas the iAs concentrations were extremely low (ND-0.033 mg/kg). Compared with the provisional tolerable weekly intake (PTWI) of the Ministry of Food and Drug Safety and Joint FAO/WHO Expert Committee on Food Additives, the percentages of PTWI of Cd, Pb, and tHg were 0.239%, 0.001-0.049%, and 0.013-0.302%, respectively. These findings reveal that there is no potential health risk by heavy metals through the consumption of Russian seafood obtained in the surveyed areas.

• Journal of the Korean Recycled Construction Resources Institute
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• 제8권4호
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• pp.404-412
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• 2020

Herein, the properties and self-healing performance of cement mortar incorporating calcium sulfoaluminate(CSA), crystalline admixture(CA), and magnesium oxide(MgO) were investigated. Mortar strength test and water permeability experiments were conducted to analyze self-healing performance of the mortar. Also, variation in crack width were measured via digital optical microscope observation. The hydration products formed in the crack via self-healing were analyzed using x-ray diffraction(XRD), thermogravimetry(TG), and digital optical microscope. The analysis revealed that compressive strength and tensile strength increased as CA substitutional ratio increased. However, in the case of MgO replacement, the compressive strength and tensile strength decreased as the CA substitution ratio increased. The products in the recovered cracks are found to be mostly Ca(OH)2, MgCO3, and CaCO3. CaCO3 was shown to be the main healing product and had a higher portion than Ca(OH)2 and MgCO3 in the recovery products. Moreover, the optimal mix derived via water permeability and crack width results was 8% CSA + 1% CA + 2.5% MgO.

• Membrane Journal
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• 제32권5호
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• pp.292-303
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• 2022

An eco-friendly energy conversion device without the emission of pollutants has gained much attention due to the rapid use of fossil fuels inducing carbon dioxide emissions ever since the first industrial revolution in the 18th century. Polymer electrolyte membrane fuel cells (PEMFCs) that can produce water during the reaction without the emission of carbon dioxide are promising devices for automotive and residential applications. As a key component of PEMFCs, polymer electrolyte membranes (PEMs) need to have high proton conductivity and physicochemical stability during the operation. Currently, perfluorinated sulfonic acid-based PEMs (PFSA-PEMs) have been commercialized and utilized in PEMFC systems. Although the PFSA-PEMs are found to meet these criteria, there is an ongoing need to improve these further, to be useful in practical PEMFC operation. In addition, the well-known drawbacks of PFSA-PEMs including low glass transition temperature and high gas crossover need to be improved. Therefore, this review focused on recent trends in the development of high-performance PFSA-PEMs in three different ways. First, control of the side chain of PFSA copolymers can effectively improve the proton conductivity and thermal stability by increasing the ion exchange capacity and polymer crystallinity. Second, the development of composite-type PFSA-PEMs is an effective way to improve proton conductivity and physical stability by incorporating organic/inorganic additives. Finally, the incorporation of porous substrates is also a promising way to develop a thin pore-filling membrane showing low membrane resistance and outstanding durability.

• Fisheries and Aquatic Sciences
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• 제25권12호
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• pp.626-636
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• 2022

Shellfish are exoskeleton-bearing aquatic invertebrates that consume various organic and inorganic substances floating in seawater through filter feeding. Heavy metals are known as absorbed and accumulated in seawater. Some of the toxic heavy metals are highly accumulated in seawater, and exposure to them can cause a variety of risks to the human body. Since Koreans like to eat seafood, they are more likely to be exposed to contaminated seafood with heavy metals. In this study, nine types of heavy metals were analyzed on ten different shellfish species in the coastal area of South Korea. The risk assessment was also done on shellfish in which heavy metals were detected. Zinc (Zn) and copper (Cu) were identified at an average of 56.7 mg/kg (6.70 to 466 mg/kg) and 13.2 mg/kg (0.064 to 143 mg/kg), respectively. Lead (Pb) average of 0.208 mg/kg (0.000750 to 1.02 mg/kg), cadmium (Cd) average of 0.454 mg/kg (0.0388 to 1.56 mg/kg) and mercury (Hg) average of 0.0266 mg/kg (0.00548 to 0.174 mg/kg) were identified. Additionally, arsenic (As), chromium (Cr), nickel (Ni), and silver (Ag) were also identified as average concentrations of 4.02 (0.460 to 15.0 mg/kg), 0.167 (< limit of quantification [LOQ] to 0.820 mg/kg), 0.281 (< LOQ to 1.46 mg/kg), and 0.158 mg/kg (< LOQ to 1.15 mg/kg). The result indicates that the monitoring results of heavy metals in most shellfish satisfied the Korean standard. However, Pb and Cd have exceeded some foreign standards, such as the United States and the EU. The permissible human exposure calculated using the heavy metal intake and detection amount was lower than the Joint FAO/WHO Expert Committee on Food Additives human safety standard, and the risk of heavy metals from shellfish consumption was at an acceptable level.

• Korean Journal of Environmental Agriculture
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• 제36권2호
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• pp.119-128
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• 2017

BACKGROUND: Miscellaneous cereal have been largely consumed in Korea as due to their physiological functions beneficial to human health. The cereals are currently a social concern because they have been found to contain heavy metals. Thus, monitoring heavy metals in the cereals is an important requirement for food safety analysis. In this study, we determined arsenic concentration in the cereals randomly harvested from different markets. METHODS AND RESULTS: Inorganic arsenic was determined by ICP-MS coupled with HPLC system. The HPLC-ICP-MS analysis was optimized based on the limit of detection and recover test to reach $0.13-1.24{\mu}g/kg$ and 94.3-102.1%, respectively. The concentrations of inorganic arsenic equivalent to daily exposure were levels of $19.91{\mu}g/day$ in mixed grain, $1.07{\mu}g/day$ in glutinous rice, $0.77{\mu}g/day$ in black brown rice, $0.13{\mu}g/day$ in barley and $0.11{\mu}g/day$ in soybeans. CONCLUSION: The levels of arsenic in miscellaneous cereals were found lower than the recommended The Joint FAO/WHO Expert Committee on Food Additives (JECFA) levels, suggesting that the cereals marketed in Korea are not potential concern in risk assessment.

• Korean Journal of Fisheries and Aquatic Sciences
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• 제34권3호
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• pp.285-290
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• 2001

To utilize canned oyster processing waste water effectively, this study was carried out to prepare instant powdered soup using the waste water (IPSW), Instant powdered souu from oyster hot-water extracts (IPSE) was prepared by mixing hot-water extracts powder (15 g) with table salt (5 g), cream powder (19 g), milk replacer (12 g), wheat flour (20 g), corn flour (15 g), starch (5 g), glucose (7.5 g) and onion powder (1.5 g). In preparing IPSW, mixed powder from wash water and boiling liquid waste, instead of powder from hot-water extracts and table salt, was added (powder from boiling liquid waste: powder from wash water= 12: 8) and other additives were added in proportion to those in the IPSE, The IPSW consists mainly of carbohydrates (about $72\%$). It was not different from the IPSE. The volatile basic nitrogen, viable cell counts, coliform group of the IPSW contains 33.4 mg/100g, $2.2\times10^4CFU/g$, <180 MPN/100g, respectively, and its water activity has 0.257. So it was a hygienically safe and conservable instant food. The main fatty acids of IPSW were 16: 0 and 18: 1n-9. Its chemical score of protein was $61.4\%$ and its main inorganic matter was iron. According to a sensual evaluation, in contrast to the IPSE, the IPSW had a bit lower aroma but better taste, It was concluded from the above chemical and sensory evaluation that even the boiling liquid waste which had been mostly abandoned because of its high table salt content can be used as a good material for instant powdered soup if it's powdered and mixed adequately with powder from wash water, and its table salt content is properly adjusted.

• The Korean Journal of Mycology
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• 제29권2호
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• pp.79-85
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• 2001

A strain of Dictyophora echinovolvata ASI 32002 showing good fruiting body formation was selected. Analyses of chemical and nutritional components as well as antimicrobial activity of different parts of the mushroom such as mycelium, egg, and fruiting body were carried out. There were differences in the chemical compositions and the quantities depending on developmental stages of veiled lady mushroom, D. echinovolvata ASI 32002. Nitrogen, phosphate, magnesium, and calcium in inorganic chemicals were abundant in mycelium, and potassium and mineral elements were abundant in the egg and fruiting body. Mannitol and trehalose were abundant in free sugar contents. Glutamic acid and arginine in mycelium and aspartic acid and glutamic acid in egg and fruiting body were abundant in free amino acid contents. Linoleic acid, an polyunsaturated fatty acid, was abundant in all parts of the Dictyophora species, but compositions and quantities of other fatty acids varied depending on the different parts of the mushroom. It was detected that malic acid, lactic acid and acetic acid in mycelium, formic acid, acetic acid and fumaric acid in egg, and malic acid, citric acid, lactic acid, fumaric acid in fruiting body were abundant. The methanol extracts of D. echinovolvata ASI 32002 mycelium showed antifungal activity with minimal inhibition concentration (MIC) of $62{\sim}125\;{\mu}g/ml$ that was similar levels of cyclohexamide against Aspergillus awamori, Hypocrea nigricance and Trichoderma virens. The MIC of extracts from mycelium and fruiting body against Candida albicans was $250\;{\mu}g/ml$, similar to that of tetracycline. In addition to the above results, further as food additives and ingredient of cosmetics.