• Food Science and Preservation
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• v.11 no.2
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• pp.160-169
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• 2004

This study was carried out to investigate the efficacy of electrolyzed water manufactured with or without diaphragm on sterilization and preservation of cut-celery and shelled raw oyster. In cut-celery, total viable cell count and coliform group in the treatment of electrolyzed water were decreased to about 1/200∼1/1,000 level and about 1/100 level comparing non-treated ones. But moisture content, pH, hardness, vitamin C and residual chlorine content were showed a little difference among treatments up to 10 days at 10$^{\circ}C$. L and a color values were gradually increased in all treatments, and color differences($\Delta$E) were remarkable between treatment and untreatment sample. In overall acceptability, cut-celery treated with electrolyzed water showed somewhat higher score than that of other ones treated with tap water and 100 ppm NaClO solution until 5 days of storage. After 48 hours of storage, it was showed that VBN, total viable cell count and coliform count of shelled raw oyster treated with electrolyzed alkali water produced by non-diaphragm system are lower by about 3 mg%, 1∼2 log cycle and 2 log cycle respectively than that of ones treated with sea water. Total viable cell count of shelled raw oyster just after treatment was lower by about 1 log cycle than that of ones treated with sea water, and any significant increment was not found after 24∼48 hours of storage.

• Korean Journal of Food Science and Technology
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• v.9 no.2
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• pp.123-130
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• 1977

A laboratory study was made to develop a simple and economic model method for the systematic determination of functional properties of 'Soy Protein Isolates (SPI)' prepared from defatted soybean meal. These are required to evaluate and to predict how SPI may behave in specific systems and such proteins can be used to simulate or replace conventional proteins. Data concerning the effects of pH, salt concentration, temperature, and protein concentration on the functional properties which include solubility, heat denaturation, gel forming capacity, emulsifying capacity, and foaming capacity are presented. The results are as follows: 1) The yield of SPI from defatted soybean meal increased to 83.9 % as the soybean meal was extracted with 0.02 N NaOH. 2) The suitable viscocity of a dope solution for spinning fiber was found to be 60 Poises by using syringe needle (0.3 mm) with 15 % SPI in 0.6 % NaOH. 3) Heat caused thickening and gelation in concentration of 8 % with a temperature threshold of $70^{\circ}C$. At $8{\sim}12\;%$ protein concentration, gel was formed within $10{\sim}30\;min$ at $70{\sim}100\;^{\circ}C$. It was, however, disrupted rapidly at $125\;^{\circ}C$ of overheat treatment. The gel was firm, resilient and self-supporting at protein concentration of 14 % and less susceptible to disruption of overheating. 4) The emulsifying capacity (EC) of SPI was correlated positively to the solubility of protein at ${\mu}=0$. At pH of the isoelectric point of SPI (pH 4.6), EC increased as concentration of sodium chloride increased. Using model system$(mixing\;speed:\;12,000\;r.p.m.,\;oil\;addition\;rate:\;0.9\;ml/sec,\;and\;temperature\;:\;20{\pm}1\;^{\circ}C)$, the maximum EC of SPI was found to be 47.2 ml of oil/100 mg protein, at the condition of pH 8.7 and ${\mu}=0.6$. The milk casein had greater EC than SPI at lower ionic strength while the EC of SPI was the same as milk casein at higher ionic strength. 5) The shaking test was used in determining the foam-ability of proteins. Progressively increasing SPI concentration up to 5 % indicated that the maximum protein concentration for foaming capacity was 2 %. Sucrose reduced foam expansion slightly but enhanced foam stability. The results of comparing milk casein and egg albumin were that foaming properties of SPI were the same as egg albumin, and better than milk casein, particularly in foam stability.

• Journal of Microbiology and Biotechnology
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• v.10 no.3
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• pp.349-354
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• 2000

Abstract A facultative alkalophilic gram-negative Vibrio metschnikovii strain RH530, isolated from the wastewater, produced several alkaline proteases (VAP) including six alkaline serine proteases and a metalloprotease. From this strain, high yielding YAP mutants were isolated by NTG treatment. The isolated mutant KS1 showed nine times more activity than the wild-type after optimization of the culture media. The production was regulated by catabolite repression when glucose was added to the medium. The effects of several organic nitrogen sources on the production of the YAP were investigated to avoid catabolite repression. The combination of 4% wheat gluten meal (WGM), 1.5% cotton seed flour (eSF), and 5% soybean meal (SBM) resulted in the best production when supplemented with 1% NaCl. The YAP showed a resistance to surfactants such as $sodium-{\alpha}-olefin$ sulfonate (AOS), polyoxy ethylene oxide (POE), and sodium dodecyl sulfate (SDS), yet not to linear alkylbenzene sulfonate (LAS). However, the activity of the YAP was restored completely when incubated with LAS in the presence of POE or $Na_2SO_4$. The YAP was stable in a liquid laundry detergent containing 6.6% SLES (sodium lauryl ether sulfate), 6.6% LAS, 19.8% POE, and stabilizing agents for more than two weeks at $40^{\circ}C$, but the stability was sharply decreased even after 1 day when incubated at $60^{\circ}C$. A washing performance test with the YAP exhibited it to be a good washing power by showing 51 % and 60% activity at $25^{\circ}C{\;}and{\;}40^{\circ}C$, respectively, thereby indicating that the YAP also has a good detergency at a low temperature. All the results suggest that the YAP produced from the mutant strain KSI has suitable properties for use in laundry detergents.rgents.

• Reproductive and Developmental Biology
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• v.34 no.3
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• pp.181-184
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• 2010

Osmolarity of culture media is one of the most important factors affecting in vitro development. This study was conducted to investigate the DNA methylation status of Pre-1 and satellite sequence in pig nuclear transfer (pNT) embryos produced under different osmolarity culture conditions. Control group of pNT embryos was cultured in PZM-3 for six days. Other two treatment groups of pNT embryos were cultured in modified PZM-3 with 138 mM NaG or 0.05M sucrose (mPZM-3, 320 mOsmol) for two days, and then cultured in PZM-3 (270 mOsmol) for four days. Previous our studies have reported that pNT embryos cultured in both hypertonic media showed significantly higher blastocyst formation rate than that of control. The DNA methylation status of the satellite sequences in blastocyst was characterized using bisulfite-sequencing technology. The satellite region had a similar methylation pattern of in vivo blastocyst among two culture groups excepting the control group. Each level of methylation is that the satellite DNA moderately methylated (43.10% of PZM-3; 56.12% of NaCl; 55.06% of sucrose; 60.00% of in vivo embryos). As a result of the sequence of PRE-1, CpG methylation pattern was similar to three groups, including in vivo group. In case of the satellite DNA region, the osmolarity conditions were affected CpG DNA methylation status while PRE-1 sequence was not affected CpG DNA methylation in pNT blastocyst stage. These results indicate that the modification of osmolarity in a culture media may influence to spatially change of DNA methylation of repetitive sequence for pNT embryo development.

• Microbiology and Biotechnology Letters
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• v.34 no.1
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• pp.7-14
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• 2006

Feather, generated in large quantities as a byproduct of commercial poultry processing, is almost pure keratin, which is not easily degradable by common professes. Four strains, SMMJ-2, FL-3, NO-4 and RM-12 were isolated from soil for production of extracellular keratinolytic protease. They were identified as Bacillus sp. based on their morphological and physiological characteristics. They shown high protease activity on 5.0% skim milk agar medium and produced a substrate like mucoid on keratin agar medium. Bacillus sp. SMMJ-2 had a faster production time for producing keratinolytic protease than other strains. This strain did not completely degrade whole chicken feather for five days in basal medium but completely degraded whole chicken feather when supplied with nitrogen source for 40hours in keratinolytic producing medium ($0.7%\;K_{2}HPO_{4},\;0.2%\;KH_{2}PO_{4},\;0.1%$ fructose, 1.2% whole chicken feather, $0.01%\;Na_{2}CO_3$, pH 7.0). When supplied with chicken feather as nitrogen source, keratinolytic protease activity was 89 units/ml/min. When soybean meal was used as nitrogen source, the keratinolytic protease production reached a maximum of 106 units/ml/min after 48 hours under $30^{\circ}C$, 180 agitation. To isolate the keratinolytic protease, the culture filtrate was precipitated with $(NH_4)_{2}SO_4$ and acetone. The recovery rate of keratinolytic protease was about 96% after treatment with 50% acetone. The enzyme was stable in the range of $30{\sim}50^{\circ}C$ and pH $6.0{\sim}12.0$.

• Journal of Food Hygiene and Safety
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• v.20 no.4
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• pp.217-224
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• 2005

When L. monocytogenes ($10^{5}CFU/mL$) at exponential phase cells were heated for 5 min at $65^{\circ}C$ in the presence of the bacteriocin (30 BU/mL) produced by E. faecium MJ-14, the number of viable cells was markedly reduced at p < 0.05. The bactericidal effect of bacteriocin showed synergism with combination ot organic acids (citric acid or acetic acid) or chemical preservatives (sodium benzoate, sodium lactate, sodium nitrate or potassium nitrate). For example, the number of viable cells was reduced by 4.8 log units under combination of the bacteriocin (30 BU/mL) and sodium nitrate ($100{\mu}g/mL$), while it was reduced by 1.1 log unit only under single treatment of the bacteriocin after 12 k at $37^{\circ}C$. The addition of the bacteriocin (300 BU/mL) into skim milk inoculated with L. monocytogenes ($10^{5}$CFU/mL) reduced the cells by 1.5 log unit, in case of the cell suspension stored at $4^{\circ}C$ for 24 hr. Moreover, L. monocytogenes was reduced by 2 log unit when stored at $-20^{\circ}C$ for 7 days in gound pork added with 300 BU/mL of 린e bacteriocin.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.5
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• pp.473-477
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• 2001

Chitosan has been used as an effective adsorbant for the treatment of wastewater from seafood processing. We investigated the effects of deacetylation degree (DD) and molecular weight (MW) of chitosan on protein adsorption ability and also the optimum conditions of chitosan treatment for protein adsorption in 3 kinds of protein (albumin, hemoglobin and albumin-myoglobin mixture) solutions. The higher deacetylation degree and the lower molecular weight chitosan, the higher adsorption for water soluble proteins was accomplished. The optimum pHs for adsorption of albumin, hemoglobin and albumin-myoglobin mixture (4: 1, w/w) were 4.0, 7.0 and 4.0 respectively and the optimum time was $3\~4$ hrs for all proteins. Sodium chloride in the model system of protein solution was a preventing factor for protein adsorption ability of chitosan (DD=$80\%$, MW=350 kDa).

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.7 s.155
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• pp.1025-1033
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• 2006

Kenaf bast can be obtained by decortication of Kenaf stem. Kenaf fibers are much more rough than cotton fiber because they include impurities as pectin, lignin and hemicellulose besides cellulose. The purpose of this research is to investigate the distribution of kenaf fiber length and diameter during the processes of removing impurities. To remove pectin, kenaf bast was retted chemically. A half of the retted kenaf fiber bundle were scoured and bleached. The other half one were treated with $NaClO_2$ solution to remove lignin, and were treated with sodium hydroxide solution to remove hemicellulose. Four kinds of specimens that were obtained for investigating physical characteristics. Length and diameter of 100 fibers on each specimen was measured. The tensile strength of 100 fiber bundles were measured. And also the color values of them were measured with spectrocolorimeter. The length of retted kenaf fiber was 16.97cm. Then it decreased to 11.43cm after bleaching. Kenaf fiber bundles could be finer by chemical processes that remove non-cellulosic materials. The thickness of retted fiber was $132{\mu}m$. And after undergoing the chemical processes to remove non-cellulosic materials, the thickness of kenaf fiber became finer as $73{\mu}m$. Tensile strength of the retted kenaf fiber bundles was 11.37Mpa. The retted kenaf fiber lost their strength as 22.6% by bleaching and as 18.3% by treatment for removing lignin. The retted kenaf fiber showed low whiteness as 56.48 of L*value. After bleaching, the kenaf fibers have creamy white color and their whiteness got 90.02 of L*value. After the treatment for removing hemicellulose, the kenaf fibers also have creamy white color and their whiteness got L* value of 79.02.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.9 no.1
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• pp.19-24
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• 1976

To examine the storage effect of the dry cured cultured undaria pinnetifida, its components were researched according to different places and periods of production and in heat treatment of it, how the different time, temperature and salt concentration can effect on its storage was researched as follows. In Pohang and Yeosu districts the most suitable period of processing was around the end of December and in Wando district, around the end of January. When it was heat-treated separately at $90^{\circ}C\;and\;100^{\circ}C$ there of occurred the comparative low increase of organic acids and volatile acids, and the slight decrease of pigment. When it was heat-treated in sea water and satuarated NaCl solution, the obvious change was not found in all components, and in fresh water organic acids and volatile acids were conspicuously increased. When it was heat-treated according to the different heating time (long or short), there was no remarkable change in all components, but when heat-treated for 20 sec. the decrease of carotenoid was conspicuous. When heat-treated for 40 sec. separately at $90^{\circ}C\;and\;100^{\circ}C$ in sea water, better effect for storage was resulted.

• Composites Research
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• v.31 no.5
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• pp.186-191
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• 2018

Condition and properties of composites with different chemical structure of epoxy matrix were observed after saline solution treatment. Epoxy was used as matrix and the flexibility was controlled by using 2 typed-epoxies and 3 types hardeners (amine, acid anhydride and amide). Saline water treatment was conducted with 6 wt% NaCl solution at $60^{\circ}C$ for 0, 15, and 30 days. Cross section was observed and interfacial and mechanical and properties was evaluated. Amine type exhibited the highest crosslinking density and mechanical and interfacial properties whereas water absorbance was lowest. It is because that the water molecules can be hardly penetrate into the epoxy matrix or the interface between epoxy and glass fiber and it leads to saline water resistance of composites.