• Food Science of Animal Resources
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• v.30 no.6
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• pp.923-929
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• 2010

Colostral whey prepared from colostrum (pooled from first six post-partum milkings) was heated for 10 min at $100^{\circ}C$ Heated colostral whey was incubated with 1% enzymes (protein equivalent basis) for 15, 30, 60, 90, and 120 min at $50^{\circ}C$. Papain, pepsin, trypsin, and alcalase produced different degrees of hydrolysis (DH), 10.66%, 12.42%, 10.83%, and 25.31%, respectively, at an incubation time of 120 min. The SDS-PAGE reveals that significant amounts of bovine serum albumin (BSA), ${\beta}$-lactoglobulin (${\beta}$-LG), and ${\alpha}$-lactalbumin (${\alpha}$-LA) survived papain digestion. In contrast, pepsin completely removed BSA but not ${\beta}$-LG present in heated colostral whey. Alcalase completely eliminated BSA, ${\beta}$-LG, and ${\alpha}$-LA. This differential hydrolysis was confirmed by reversed-phase HPLC analysis. Using ion-exchange chromatography, fraction-1 (F-1) was obtained from alcalase hydrolysate at a NaCl gradient concentration of 0.25 M. Reversed-phase HPLC chromatograms of alcalase F-1 showed numerous small peaks, which probably indicate that a variety of new peptides were produced. Iron content of alcalase F-1 was 28.94 ppm, which was the highest among all enzyme fractions, whereas iron content of colostral whey was 36.56 ppm. Main amino acids contained in alcalase F-1 were Thr (15.45%), Glu (14.12%), and Ser (10.39%). Therefore, alcalase can be used to generate good iron-binding peptides in heated colostral whey, and the resulting iron-binding peptides could be suitable as a value-added food ingredient for food supplements.

• Journal of Powder Materials
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• v.21 no.3
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• pp.202-206
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• 2014

Leaching of MOCVD dust in the LED industry is an essential stage for hydro-metallurgical recovery of pure Ga and In. To recover Ga and In, the leaching behavior of MOCVD scrap of an LED, which contains significant amounts of Ga, In, Al and Fe in various phases, has been investigated. The leaching process must be performed effectively to maximize recovery of Ga and In metals using the most efficient lixiviant. Crystalline structure and metallic composition of the raw MOCVD dust were analyzed prior to digestion. Subsequently, various mineral acids were tested to comprehensively study and optimize the leaching parameters such as acidity, pulp density, temperature and time. The most effective leaching of Ga and In was observed for a boiling 4 M HCl solution vigorously stirred at 400 rpm. Phase transformation of GaN into gallium oxide by heat treatment also improved the leaching efficiency of Ga. Subsequently high purity Ga and In can be recovered by series of hydro processes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.832-839
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• 2014

To evaluate the digestive characteristics and bioavailability of dietary soybean meal (SBM), the post-prandial changes in the gastric contents of rainbow trout Oncorhynchus mykiss were determined for 24 h after feeding of SBM diets. A curve estimation of regression diagnostics using a comparison of the adjusted $r^2$ and probability was performed to test the tendency of the post-prandial changes and gave a quadratic polynomial (exponential) regression for all experimental groups. The gastric evacuations rates (GER) for higher-SBM groups were slower than those for lower-SBM groups. The estimated GER (digestion time) for 75% gastric content for fish fed a 70% SBM diet was 1.63 times longer than that for fish fed the control diet. Despite the fact that the pH values in the gastric contents rose from 4.05 at 0 h to 5.12-5.38 at 1 h after feeding, then dropped to 4.57-4.83 at 9 h, with no significant differences among experimental groups, the gastric moisture contents increased significantly in the higher-SBM groups. This is most likely due to an increase in digestive juices in the higher-SBM groups, rather than water introduced externally. The percentage of soluble nitrogen in the gastric contents of fish fed the higher-SBM diets was higher than that in the fish fed the control diet, and the SBRs (stomach weight/body weight${\times}100$) in the higher-SBM groups (diets 4, 5, 6 and 7) were also significantly higher than the SBR of the control group (P<0.05). This may indicate that the protein in SBM can be digested slowly due to physiological digestive adaptation in rainbow trout.

• Microbiology and Biotechnology Letters
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• v.38 no.4
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• pp.405-413
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• 2010

Fig (Ficus carica L.) belongs to the mulberry tree (Moraceae) which is one of the oldest fruits in the world. It has been used as a digestion promoter and a cure for ulcerative inflammation and eruption in Korea. The present study investigated the antimicrobial activity of methanol (MeOH) extract of fig leaves against methicillin-resistant Staphylococcus aureus (MRSA) isolated in clinic. The MeOH extract (MICs, 2.5 to 20 mg/mL; MBCs, 5 to 20 mg/mL) was demonstrated as antibacterial activity in isolates MRSA 1-20. The administration of the MeOH extract in combination with oxacillin or ampicillin induced a reduction of ${\geq}$4-8-fold in all tested bacteria, which was considered to be synergistic based on a FICI of ${\leq}$0.375-0.5. Furthermore, time-kill study was found that a combination of MeOH extract with oxacillin or ampicillin produced a more rapid decrease in the concentration of bacteria CFU/mL than MeOH extract alone. The results suggest that fig leaves could be employed as a natural antibacterial agent in MRSA infection care products.

• Journal of the East Asian Society of Dietary Life
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• v.12 no.5
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• pp.364-369
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• 2002

Mulberry leaves are believed to be a potent inhibitor of intestinal $\alpha$-glycosidase and the digestion of sucrose in the small intestine. Mulberry leaves are also blown to help prevent the postprandial hyperglycemia. The objective of this study was to elucidate the functionality and anti-hyperglycemic effect of mulberry leaves, and to develop a functional drink using mulberry leaf, silk peptide and oriental medicine. Several mixtures of mulberry lear extract silk peptide and oriental medicine were made for the purpose of manufacture and formulation of products. These mixtures were tested to check the $\alpha$-glycosidase inhibition effect to find the best formula. The optimum conditions for a mulberry leaf hot water extract were that the size of leaf was under 3mm, the amount of leaf needed 50~100 g/L, extraction temperature 9$0^{\circ}C$ and extraction time 2 hr. The yield of extraction was 20~25%. The anti-hyperglycemic effect of mulberry leaves was at maximum when the concentrations of mulberry leaf extract and silk peptide were 1% and 0.1%, respectively.

• Journal of the Korean Chemical Society
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• v.44 no.6
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• pp.563-572
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• 2000

The analysis of coal ash is very important to predict some factors, such as slagging and fouling in the boiler, and to determine optimum mixing ratios of the each coals used. In ASTM, the analysis of coal ash is clarified to use lithium metaborate (LiBO$_2$) as a fluxing agent and then to analyze the pre-treated samples using AAS. However, it takes too much time and efforts to analyze many samples by ASTM method, as a result, this method is not proper in our laboratory in charge of analyses of all power plants. So we tried to establish more convenient and accurate analytical method of coal ash by 3 different methods which are 2 different pre-treatment methods (fusion dissolution and microwave digestion) and XRF analysis method using a clear pellet. Although all 3 methods can be utilized to analyze the major elements of coal ash, each method has its own characteristics, therefore, each method should be chosen according to its own purpose.

• Journal of Environmental Health Sciences
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• v.35 no.3
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• pp.214-219
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• 2009

This study examined the removal efficiency of the nitrogen and phosphorus in order to compensate for the combined process of ATAD(Autothermal Thermophilic Aaerobic Digestion) and EGSB(Expended Granular Sludge Bed), which are treatment methods for livestock wastewater, by introducing SBR(Sequencing Batch Reactor) as post-treatment process. The analysis on the treatment efficiency of each operation mode showed that, in the case of T-N, the treatment efficiency were 67.1% and 74.2% for Run-1 and Run-2, respectively, and in the case of T-P, the values were 71.2 and 74.1, respectively, which are indicating that the treatment efficacy is higher in the condition of Run-1, in which the time period of Anoxic and Aerobic segments were increased. In addition, the result of analyzing removal characteristics of nitrogen and phosphorus by Influx load showed that removal efficiency of nitrogen was better in the case of high influx load than in the case of low influx load. Regardless of Influx load, phosphorus showed constant influx concentration, so that removal efficiency of phosphorus was influenced littler by Influx load than that of nitrogen. This study also fed methanol as an external carbon source and performed experiment to induce denitrification under anoxic condition by using nitrate among nitrogen compounds of SBR reactor, and the results showed that intermittent feeding was more effective in Nitrogen Removal than composite feeding.

• Preventive Nutrition and Food Science
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• v.18 no.3
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• pp.163-168
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• 2013

In this study, we investigated the inhibitory effects of Baechu kimchi added Ecklonia cava on the activities of ${\alpha}$-glucosidase and ${\alpha}$-amylase and its alleviating effect on the postprandial hyperglycemia in STZ-induced diabetic mice. Baechu kimchi added Ecklonia cava (BKE, 15%) was fermented at $5^{\circ}C$ for 28 days. Optimum ripened BKE was used in this study as it showedthe strongest inhibitory activities on ${\alpha}$-glucosidase and ${\alpha}$-amylaseby fermentation time among the BKEs in our previous study. The BKE was extracted with 80% methanol and the extract solution was concentrated, and then used in this study. The BKE extract showed higher inhibitory activities than Baechu kimchi extract against ${\alpha}$-glucosidase and ${\alpha}$-amylase. The $IC_{50}$ values of the BKE extract against ${\alpha}$-glucosidase and ${\alpha}$-amylase were 0.58 and 0.35 mg/mL, respectively; BKE exhibited a lower ${\alpha}$-glucosidase inhibitory activity but a higher ${\alpha}$-amylase inhibitory activity than those of acarbose. The BKE extract alleviated postprandial hyperglycemia caused by starch loading in normal and streptozotocin- induced diabetic mice. Furthermore, the BKE extract significantly lowered the incremental area under the curve in both normal and diabetic mice (P<0.05). These results indicated that the BKE extract may delay carbohydrate digestion and thus glucose absorption.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.465-469
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• 2006

Two mesophilic trickling bed bioreactors filled with two different types of media, hydrophilic- and hydrophobic-cubes, were designed and tested for hydrogen production via anaerobic fermentation of sucrose. Each reactor consisted of a column packed with polymeric cubes and inoculated with heat-treated sludge obtained from anaerobic digestion tank. A defined medium containing sucrose was fed with changing flow rate into the capped reactor, hydraulic retention time and recycle rate. Hydrogen concentrations in gas-phase were constant, averaging 40% for all conditions tested. Hydrogen production rates increased up to $10.5 L{\cdot};h^{-1}{\cdot}L^{-1}$ of reactor when influent sucrose concentrations and recycle rates were varied. Hydrophobic media provided higher value of hydrogen production rate than hydrophilic media at the same operation conditions. No methane was detected when the reactor was under a normal operation. The major fermentation by-products in the liquid effluent of the both trickling biofilters were acetate and butyrate. The reactor filled with hydrophilic media became clogged with biomass and bio gas, requiring manual cleaning of the system, while no clogging occurred in the reactor with hydrophobic media. In order to make long-term operation of the reactor filled with hydrophilic media feasible, biofilm accumulation inside the media in the reactor with hydrophilic media and biogas produced from the reactor will need to be controlled through some process such as periodical backwashing or gas-purging. These tests using trickling bed biofilter with hydrophobic media demonstrate the feasibility of the process to produce hydrogen gas in a trickle-bed type of reactor. A likely application of this reactor technology could be hydrogen gas recovery from pre-treatment of high carbohydrate-containing wastewaters.

• Journal of Korean Society on Water Environment
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• v.35 no.4
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• pp.299-307
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• 2019

The purpose of this study was to investigate the effect of low temperature thermal pre-treatment on biodegradation of waste activated sludge for anaerobic digestion as a countermeasure for increasing sludge generation. The experimental condition was accomplished in 2 %, 4 %, and 6 % TS concentration, and $70^{\circ}C$, $80^{\circ}C$, $90^{\circ}C$ of temperature for a maximum of 120 minutes retention time. Then, it was followed by analysis of physical/chemical properties, BMP test and composition of biogas. The biogas characteristic was evaluated by applying the modified Gomperz model. As a result, solubility of dissolved substrate, such as $SCOD_{Cr}$, soluble carbohydrate, and soluble protein, and biogas production increased as temperature increased. Solubilization efficiency at $90^{\circ}C$ was 18.4 %, 17.03 % and 16.88% in 2 %, 4 %, and 6 % TS concentration respectively. Also, solubilization rates of carbohydrate and protein similarly increased. BMP test results also showed that methane production in excess sludge increased to 0.194, 0.187 and $0.182m^3/kg$ VS. respectively, and lag phase decreased to 0.145, 0.220, 0.351 day due to acceleration of the hydrolysis step. Consequently, low-temperature thermal pre-treatment could increase biodegradability of sludge, positively affecting biogas production and sludge reduction.