• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.2
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• pp.226-233
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• 1993

Enzymatic hydrolysates of food proteins (defatted soybean cake, egg albumin and casein) were tested for inhibitory activity against angiotensin-I converting enzyme (ACE). Food proteins were hydrolysed with complex enzyme, bromelain, alcalase, $\alpha$-chymotrypsin, trypsin, papain and pepsin by heating method. The hydrolysates obtained from the treatment of complex enzyme and bromelain showed the higher ACE inhibitory activity. ACE inhibitory activity of hydrolysates exhibited a tendency to be increased until 8hrs and increased with increment of concentration. The activity was also stable by heat treatment at 10$0^{\circ}C$ for 20min. Molecular weight of active fraction was about 1, 400 and defatted soybean cake hydrolysate below 1, 400 in case of defatted soybean cake hydrolysate treated with alcalase. Amino acid of the active fractions was abundant in Asp, Glu, Lys, lle, Leu, Ala and Val.

• Korean journal of applied entomology
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• v.29 no.3
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• pp.157-164
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• 1990

The surface patterns and the structures of transverse section of the egg-shell of the sikmoth, Bombyx mandarina, have been described by scanning electron microscope. Three spatially differentiated cross section, called lamellar, conic pillar and cover layers, are found on the mature eg-shell. Silkmoth chorion proteins were detected more than 80 components from a single chorion by two-dimensional electrophoresis. Major protein components of the egg-shell have bee identified on the basis of their isoelectric points and molecular weights, pH 4-6 and 6-30 kd. Several protein components are found entirely or predominantly in th cover layers.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.6
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• pp.753-760
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• 1995

This study was conducted to determine the serum vitellogenin (VTG) concentration changes during the ovulation period in elkhorn sculpin, Alcichthys alcicornis. The results of sepacryl S-300 showed that the molecular weight of VTG could be 380,000. SDS-polyacrylamide gel electrophoresis (SDS-PAGE) analysis may indicate that the purified VTG consists of three subunits with molecular weights of 180,000, 118,000 and 85,000, respectively. Yolk protein purified from the egg extracts was eluted on an equilibrated sephacryl S-300 column, and its molecular weight was estimated 250,000. The precipitation lines of the female serum against the antiserum of the egg extracts were fused completely by immunoelectrophoresis and immunodiffusion analysis. VTG was detected in the serum, and hepatocytes from males injected with $17\beta-estradiol\;(E_2).$ Furthermore, VTG was immunochemically similar to yolk proteins. The concentration of VTG was high before ovulation $(9.80\pm0.81-11.02\pm0.09 mg/ml),$ and then decreased rapidly after ovulation $(less\;than\;6.19\pm0.59 mg/ml).$ This study suggested that VTG was synthesized in the liver by the action of $E_2$ and released to blood, and then incorporated into oocytes.

• 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.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.5
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• pp.435-442
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• 2011

This study was conducted to optimize the processing of high quality surimi gel from unmarketable cultured bastard halibut Paralichthys olivaceus. According to endogenous enzyme activity and processing optimization, high quality surimi gel from unmarketable cultured bastard halibut was prepared by mixing 3.0% (w/w) salt, 2.4% (w/w) starch, 5.0% (w/w) egg white and 4.8% (w/w) ice water in a Stephan mixer, set at $5^{\circ}C$ for 24 h, followed by boiling for 30 min, and finally cooling for 30 min. The strength of the surimi gel from unmarketable cultured bastard halibut prepared by the above processing method was $1,257\;g{\times}cm$, which was 33% higher than that of a commercial surimi gel from Alaska pollock, grade SA.

• Applied Biological Chemistry
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• v.14 no.3
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• pp.201-205
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• 1971

The electrophoretic patterns of the thin and thick layers of EWP were observered and the densitometry was conducted. 1. Most characteristic were the patterns of both layers at 7-day incubation compared with those of fresh stage. 2. After 15 days the patterns of both layers were almost same. 3. The ratio of some components of the fresh EWP is in a good accordance with the other wisely measured data.

• Food Science of Animal Resources
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• v.22 no.3
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• pp.259-266
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• 2002

The egg shell membrane degrading isolated from soil was identified as Bacillus licheniformis by 16S rDNA identification method. A keratinase was isolated from the Baciilu licheniformis culture. DEAE-cellulose ion-exchange and Sephadex C-75 gel chromatograhies were used to purify the enzyme. The specific activity was increased 17.3-fold by the purification procedures. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis and Sephadex G-75 chromatography indicated that the purified keratinase was monomeric and had a molecular weight of 65 kDa. The enzyme showed optimum activity at pH 9.0, and was stable above pH 9.0. The optimum temperature was 50$\^{C}$ and the enzyme was stable in the temperature ranges from 20$\^{C}$ to 50t. By the addition of 1 mM and 10 mM FeSO4, the activities of the enzyme were increased to 111$\pm$4.6% and 133$\pm$3.79%, respectively. The keratinase was an alkaline serine pretense because it was inhibited only by phenylmethylsulfonylfluorice (PMSF).

• International Journal of Industrial Entomology and Biomaterials
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• v.2 no.1
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• pp.55-59
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• 2001

The vitellin of the red flour beetled Tribolium castaneum Herbst was purified and characterized. The vitellin of T. castaneum was purified by the FPLC techniques, anion exchange chromatography and gel permeation chromatography. In native-polyacrylamide gel electrophoresis, vitellin of T. castaneum was detected as a single band. This native vitellin has molecular weight of 440 kDa. The vitellin of T. castaneum is composed of three polypeptides, designated Vnl (178 kDa), Vn2 (168 kDa) and Vn3 (52 kDa) in SDS-polyacrylamide gel electrophoresis. Three subunits of vitellin were presented in the female adult hemolymph and egg extracts, but not observed in the male. These three polypeptides gradually decreased during embryogenesis. Polyclonal antiserum raised against purified vitellin reacted with the three polypeptides, Vnl, Vn2 and Vn3. Antisera raised against Vn1 and Vn2 cross-reacted with the two large subunits, Vnl and Vn2, respectively. Another subunits Vn3, however, was not cross-reacted with these two antisera. Also, antiserum raised against Vn3 did not cross-react with the Vn1 and Vn2.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.2
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• pp.83-88
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• 2005

Protease inhibitors were purified from the eggs of Alaska pollock (Theragra chalcogramma) using the following purification steps: ammonium sulfate precipitation, ion exchange, gel permeation, and high performance liquid chromatographies (HPLC). The protease inhibitor from the heated eggs of Alaska pollock was not as well purified. In addition, the heated eggs showed lower specific inhibitory activity than the unheated eggs. The purification yields after ammonium sulfate precipitation, ion exchange, and gel permeation chromatographies were 22.7$\%,\;15.3\%$,and $4.4\%$, respectively. There were two kinds of protease inhibitors on the gel permeation chromatography pattern Their molecular weights were estimated to be 66,700 and 16,000 Da, respectively. Both were classified as a cysteine protease inhibitor because of the existence of inhibiting papain, which is one of cysteine proteases.

• Journal of Animal Environmental Science
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• v.10 no.2
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• pp.119-126
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• 2004

The protein in the extracts from the skins of pineapple and kiwi and the optimal conditions to hydrolyze blood, egg and gluten meals with them were investigated. Protein analysis by SDS-polyacylamide gel electrophoresis showed one protein band with 22 kd molecular weight in the pineapple skin extract, and Hve protein bands with 27 kd, 22.5 kd, 22 kd, 19 kd, and 14.4 kd molecular weight in the kiwi skin extract. The 22 kd protein in the pineapple skin extract is assumed to be bromelain, and the 27 kd protein in the kiwi skin extract is assumed to be actinidin, both are pretense. The optimal conditions for hydrolysis of blood, egg, and gluten meals we: 6-24 hours in time, $60^{\circ}C$ in temperature, and pH 4-pH 7.