• Korean Journal of Food Science and Technology
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• v.20 no.6
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• pp.883-889
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• 1988

The salted small shrimps(Acetes japonicus) were fermented for 3 months at room temperature. During the period of fermentation, the changes of shrimp protein properties were determined. The extractability of soluble protein was slightly decreased in 1 month fermentation, but thereafter increased. The contents of 10% TCA soluble fraction were gradually increased during 3 month fermentation, and the rate of 10% TCA soluble fraction/total soluble protein was also greatly increased during the period of fermentation. Sephadex G-100 gel filtration pattern was changed after 1 month fermentation, showing the disappearance of low molecular weight protein peaks, the decomposition and the delay of elution time of main shrimp protein peaks. Polyacrylamide gel disc electrophoresis patterns showed the degradation of main protein bands into lots of smaller bands after 1 month fermentation. The contents of total free amino acids were slightly decreased in 1 month fermentation and then gradually increased during the Period of fermentation. The rate of free amino acids/soluble protein was steadily increased during the period of fermentation, but the rate of free amino acids/10% TCA soluble fraction was decreased continually during the period of fermentation. The contents of most free amino acids were increased during the period of fermentation, but those of histidine and arginine were greatly decreased in 1 month fermentation. Ammonia was increased after 1 month fermentation. The pH value of salted shrimp was slowly changed during 3 months of fermentation, showing increase from 7.8 to 8.2.

• Korean Journal of Food Science and Technology
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• v.2 no.1
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• pp.121-126
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• 1970

The utilization of soybean milk has lasted for past several thousand years, mostly in Orient as a Precious food or as a substitute for cow's milk. There are several hundred varieties in soybean that is called Glycine max Merryl There are three typical varieties, Yellow, Black and Green. However, these are due to pigment in soybean cuticle while their chemical constituents are similar (Table 2). Soybean milk is constituted of protein, fat and carbohydrate of soybean, and these constituents are extracted by hot water. Thus becomes emulsion which is highly digestible and nutritious for human diet. However, it was not found any report on the water extractability comparison between two different varieties Black cuticle soybean which is common in India and Yellow cuticle soybean which is common in Korea. Also there was no report on the comparison on the yield and organoleptic quality derived by varied process. Also several attempts were carried out to improve nutritional value as well as acceptability by use of food additives. A model of continuous soybean milk plant was introduced.

• Korean Journal of Environmental Agriculture
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• v.4 no.1
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• pp.25-30
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• 1985

In order to characterize relationship between accumulation of cadmium, zinc and lead in soil and soil chemical properties and also to choose a suitable soil extractant for the prediction model of heavy metal content in brown rice, four extractants-0.1 M HCl, 0.1 M $HNO_3$, 0.1 M $NH_4-oxalate$ and 0.001 M 2Na-EDTA, were compared by analyzing 84 soil samples collected from paddy fields adjacent to five zinc-minig sites. Contents of Cd, and Pb in soil increased with Zn content and those of three elements were found to be much higher in surface soil ($0{\sim}15 cm$) than suvsqrface soil ($15{\sim}30 cm$). Contents of these elements in soil were positively correlated with soil pH, but its correlation between extractable heavy metal content and organic matter or CEC varied from region to region. These three elements were negatively correlated with Mg content of soils. The extractability of the metals was in the order 0.1 M $HCI{\geq}0.1 M$ $HNO_3>0.001 M$ 2Na-EDTA>0.1 M $NH_4-oxalate$.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.6
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• pp.464-472
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• 2014

The Codex Committee of Contaminants in Food (CCCF) has been discussing a new standard for arsenic (As) in rice since 2010 and a code of practice for the prevention and reduction of As contamination in rice since 2013. Therefore, our current studies focus on setting a maximum level of As in rice and paddy soil by considering bioavailability in the remediation of As contaminated soils. This study aimed to select an appropriate single chemical extractant for evaluating the mobility of As in paddy soil and the bioavailability of As to rice. Nine different extractants, such as deionized water, 0.01 M $Ca(NO_3)_2$, 0.1 M HCl, 0.2 M $C_6H_8O_7$, 0.43 M $HNO_3$, 0.43 M $CH_3COOH$, 0.5 M $KH_2PO_4$, 1 M HCl, and 1 M $NH_4NO_3$ were used in this study. Total As content in soil was also determined after aqua regia digestion. The As extractability of the was in the order of: Aqua regia > 1 M HCl > 0.5 M $KH_2PO_4$ > 0.43 M $HNO_3$ > 0.2 M $C_6H_8O_7$ > 0.1 M HCl > 0.43 M $CH_3COOH$ > deionized water > 1 M $NH_4NO_3$ > 0.01 M $Ca(NO_3)_2$. Correlation between soil extractants and As content in rice was in the order of : deionized water > 0.01 M $Ca(NO_3)_2$ > 0.43 M $CH_3COOH$ > 0.1 M HCl > 0.5 M $KH_2PO_4$ > 1 M $NH_4NO_3$ > 0.2 M $C_6H_8O_7$ > 0.43 M $HNO_3$ > 1M HCl > Aqua regia. BCF (bioconcentration factor) according to extractants was in the order of : 0.01M $Ca(NO_3)_2$ > 1 M $NH_4NO_3$ > deionized water > 0.43 M $CH_3COOH$ > 0.1 M HCl > 0.43 M $HNO_3$ > 0.2 M $C_6H_8O_7$ > 0.5 M $KH_2PO_4$ > 1 M HCl > Aqua regia. Therefore, 0.01 M $Ca(NO_3)_2$ ($r=0.78^{**}$) was proven to have the greatest potential for predicting As bioavailability in soil with higher correlation between As in rice and the extractant.

• Nuclear Engineering and Technology
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• v.11 no.2
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• pp.105-110
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• 1979

In order to evaluate the effect of gamma ray irradiation to the soils added with several organic matters on release sad fixation of $^{65}Zn$, a soil incubation test was carried out by use of an acidic and a calcareous soil. The results obtained were summarized as follows : DTPA extractable $^{65}Zn$ decreased gradually with elapsed time of incubation owing to fixation of $^{65}$Zn by the soils but after four weeks DTPA extractable $^{65}Zn$ was reached an equilibrium state. The most parts of $^{65}Zn$ activity in the equilibrium state was found in the solid phase. The extent of zinc fixation in acidic Keumgok and calcareous Jecheon soils represented as activity basis was 89 and 93.7 per cent of applied $^{65}Zn$ respectively. Increased tendency of DTPA extractable zinc was shown by irradiating gamma ray to both soils because of $^{65}Zn$ fixation could be decreased by irradiation. The extractability of fixed $^{65}Zn$ by DTPA solution was 38.9 per cent in acidic Keumgok soil and only 9.5 per cent in calcareous Jecheon soil. Release of fixed $^{65}Zn$ by irradiation of gamma ray is closely related to pH of both soils. Much more $^{65}Zn$ could be released under low pH condition. Effect of gamma ray irradiation to organic matter sources on release of $^{65}Zn$ could not be differentiated. But in the case of nonirradiated soils, however, glucose treated soils couldrelease much more the extractable zinc as compared to those of the straw or cellulose treatment.

• Korean Journal of Poultry Science
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• v.14 no.2
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• pp.137-143
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• 1987

This study was carried out to compare the changes in the extractability, biological activity, and solubility of myofibrillar proteins and actomyosins during storage period at 4$^{\circ}C$ and -20$^{\circ}C$in pectoral. and leg muscle of broiler meat. 1. The results obtained are as fellows ; The extractabilities of myofibrillar proteins in pectoral and leg muscle were increased gradually to 7-days during storage at 4$^{\circ}C$ and decreased slightly during frozen storage at -20$^{\circ}C$. The extractabilities of actomyosins in pectoral and legmuscle were not greatly changed during cold storage and decreased gradually during frozen storage. 2. The Ca$\^$2+/-ATP ase activities of myofibrillar proteins in the both muscles were not greatly changed to 7-days during cold storage, and in the case of frozen storage, those were highest on the 2nd week, thereafter decreased with storage period. The Ca$\^$2+/-ATPase activities of actomyosins in pectoral and leg muscle were decreased sightly only frist day during cold storage and decreased gently during frozen storage. 3. Myofibrillar proteins in the both muscles were solubilized completely at 0.20M KCl in fresh meat, at 0.25M (pectoral) and 0.30M KCl (leg) in the cold storage, and at 0.30M KCl in the frozen storage. Actomyosins of both muscles were solubilized completely at 0.40M KCl in fresh meat, cold and frozen storage.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.1
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• pp.10-16
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• 1997

To confirm the possibility of seaweed extracts for functional food, water or ethyl alcohol solubles were extracted from laver, Porphyra yezoensis and evaluated those food components such as proteins, carbohydrates, nucleic acids, taurine, pigments and browning extent. The amount of proteins, polysaccharides and nucleic acids extracted decreased with increasing ethyl alcohol concentration, which was maximal when water was used as extraction solvent. The extractability of proteins, polysaccharides and nucleic acids was different between the dried and the roasted laver. Taurine was extracted about 1% from the dried and the roasted laver in the range of o~7o% ethyl alcohol concentration. The amount of carotenoids extracted by 95% ethyl alcohol from the dried and the roasted laver were 146.6 and 138.4mg%, respectively, which was 66 ~ 80% of yield extracted by methanol/acetone(1/1) solvent. The browning value of 50 ~6o% ethyl alcohol extraction group from roasted laver was highest among water/ethyl alcohol extraction group. The extraction yield was maximum when laver was extracted with water, and the value was 26.3% for the dried laver and 27.5% for the roasted layer. Organoleptic characteristics from four kinds of extraction groups containing hot water extraction showed that extracts from the roasted laver were evaluated most eminent and thought to be applicable to various preparation of food.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.8
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• pp.787-798
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• 2005

The objectives of this study were to assess extraction kinetics of heavy metals with extraction times and to assess extraction efficiencies of heavy metals with concentrations and kinds of washing solutions. Target materials were obtained from disused metal mines. Washing solutions were water, HCl(0.1, 0.3, 1.0 N), EDTA(0.01, 0.05, 0.1 M), and sodium dodecyl sulfate(SDS, 0.1. 0.5, 1.0%). Extraction efficiencies of heavy metals by water and SDS were below 1%, and extraction efficiencies of Zn and Cd were higher than those of Pb and Cu. As results, water and SDS were not effective in extracting heavy metals from mine tailings as washing solution, but extraction efficiencies of Pb and Cu with SDS solution increased as extraction time increased. Extraction kinetics of heavy metals with HCl and EDTA were faster than those with water and SDS. The majority of heavy metals were extracted within 6 hours, and extraction kinetics was almost independent of the solution concentration. Extraction kinetics of heavy metals after 6 hours was slow, but extraction kinetics was dependent on the solution concentration. Also, as concentrations of HCl and EDTA solution were stronger, heavy metals were extracted rapidly and extraction efficiencies were increased. The extraction efficiency was high in order of Cd>Pb>Zn>Cu in using 1.0 N HCl, and Pb>Cd>Zn>Cu in using 0.1 M EDTA. Consequently, extraction effectiveness was highest for Pb in using HCl, and for Pb and Cd in using EDTA with concentration increase. Extraction time of over 6 hours was not effective in extracting heavy metals.

• The Korean Journal of Pesticide Science
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• v.3 no.1
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• pp.66-77
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• 1999

In order to elucidate the fate of the residues of the bipyridylium herbicide paraquat in soil, maize plants were grown for 4 weeks on the specially-made pots filled with two different types of soils containing fresh and 6-week-aged residues of [$^{14}C$]paraquat, respectively. The mineralization of [$^{14}C$]paraquat to $^{14}CO_{2}$ during the aging period and the cultivation period of maize plants amounted to $0.13{\sim}0.18%$ and $0.02{\sim}0.17%$, respectively, of the original $^{14}C$ activities. At harvest the roots and shoots contained less than 0.1% and 0.01% of the originally applied $^{14}C$ activities, respectively, whereas the $^{14}C$ activities remaining in soil were more than 97% in both soils. The water extractability of the soil where maize plants were grown for 4 weeks was less than 1.2% of the original $^{14}C$ activities. Most of the non-extractable soil-bound residues of [$^{14}C$]paraquat were incorporated into the humin fraction. Soil pHs during the aging of soil B and after cultivation in all treatments increased. The distribution of the $^{14}C$ activities in subcellular particles of the maize plant roots was the highest in the residue fraction(incompletely homogenized tissue). Dehydrogenase activities increased after vegetation, regardless of soil aging.

• Korean Journal of Food Science and Technology
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• v.17 no.4
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• pp.248-252
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• 1985

Prunus tomentosa Thunberg seed was investigated to evaluate its possibility for use as food resources of fats and proteins. The seed contained 40.38% of crude fat and 26.59% of crude protein. The lipid fractions obtained by silicic acid column chromatography were mainly composed of 95.49% of neutral lipids, whereas compound lipids were only 4.51%. Among the neutral lipid components by thin-layer chromatography, triglycerides were 89.86%, sterols, monoglycerides, sterol esters, free fatty acids and diglycerides were 4.14%, 2.98%, 1.77%, 1.07%, and 0.18%, respectively. Oleic acid (65.06-66.05%) and linoleic acid (26.56-28.40%) were the main fatty acids in the total lipid, neutral lipid and triglyceride fractions. In the glycolipid and phospholipid fractions, predominant fatty acids were oleic acid (40.55-51.46%), linoleic acid (20.26-30.89%) and palmitic acid (17.64-21.43%). The extractability of salt soluble protein of seed was 60%, and recovery rate of main protein fraction separated by Sephadex G-200 was about 46.5%. The electrophoretic analysis showed 7 bands in seed protein.