• Korean Journal of Food Science and Technology
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• v.52 no.4
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• pp.317-324
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• 2020

In order to create the national food nutrient database, a total of 41 animal foods (ham, seafood, edible insects and eggs) were analyzed for their vitamin B₁₂ content and the applied immunoaffinity-HPLC was verified. Ham vitamin B₁₂ contents were 0.30-0.65 ㎍/100 g. Seafood showed relatively high vitamin B₁₂ level, where the values of fermented clam were the highest (26.80 ㎍/100 g) followed by fermented pollack roe. Vitamin B₁₂ was not detected in silkworm pupae and beetles, while relatively high levels were found in the two-spotted cricket imago (6.70 ㎍/100 g). Chicken and quail egg yolk had roughly 100- and 30-times higher vitamin B₁₂ levels as compared to their egg white. Vitamin B₁₂ contents in quail and chicken eggs were significantly enhanced by boiling (p<0.05). Results based on accuracy (97-102% recovery) and precision (<5% RSD) indicate that this study provides reliable vitamin B₁₂ information on animal foods consumed in Korea.

• Journal of Sericultural and Entomological Science
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• v.16 no.1
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• pp.21-48
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• 1974

The studies were carried out to disclose the physical and chemical properties of sericin fraction obtained from silk cocoon shells and its characteristics of swelling and solubility. The following results were obtained. 1. The physical and chemical properties of sericin fraction. 1) In contrast to the easy water soluble sericin, the hard soluble sericin contains fewer amino acids include of polar side radical while the hard soluble amino acid sach as alanine and leucine were detected. 2) The easy soluble amino acids were found mainly on the outer part of the fibroin, but the hard soluble amino acids were located in the near parts to the fibroin. 3) The swelling and solubility of the sericin could be hardly assayed by the analysis of the amino acid composition, and could be considered to tee closely related to the compound of the sericin crystal and secondary structure. 4) The X-ray patterns of the cocoon filament were ring shape, but they disappeared by the degumming treatment. 5) The sericin of tussah silkworm (A. pernyi), showed stronger circular patterns in the meridian than the regular silkworm (Bombyx mori). 6) There was no pattern difference between Fraction A and B. 7) X-ray diffraction patterns of the Sericin 1, ll and 111 were similar except interference of 8.85A (side chain spacing). 8) The amino acids above 150 in molecular weight such as Cys. Tyr. Phe. His. and Arg. were not found quantitatively by the 60 minutes-hydrolysis (6N-HCI). 9) The X-ray Pattern of 4.6A had a tendency to disappear with hot-water, ether, and alcohol treatment. 10) The partial hydrolysis of sericin showed a cirucular interference (2A) on the meridian. 11) The sericin pellet after hydrolysis was considered to be peptides composed with specific amino acids. 12) The decomposing temperature of Sericin 111 was higher than that of Sericin I and II. 13) Thermogram of the inner portioned sericin of the cocoon shell had double endothermic peaks at 165$^{\circ}C$, and 245$^{\circ}C$, and its decomposing temperature was higher than that of other portioned sericin. 14) The infrared spectroscopic properties among sericin I, II, III and sericin extracted from each layer portion of the cocoon shell were similar. II. The characteristics of seriein swelling and solubility related with silk processing. 1) Fifteen minutes was required to dehydrate the free moisture of cocoon shells with centrifugal force controlled at 13${\times}$10$^4$ dyne/g at 3,000 R.P.M. B) It took 30 minutes for the sericin to show positive reaction with the Folin-Ciocaltue reagent at room temperature. 3) The measurable wave length of the visible radiation was 500-750m${\mu}$, and the highest absorbance was observed at the wave length of 650m${\mu}$. 4) The colorimetric analysis should be conducted at 650mu for low concentration (10$\mu\textrm{g}$/$m\ell$), and at 500m${\mu}$ for the higher concentration to obtain an exact analysis. 5) The absorbing curves of sericin and egg albumin at different wave lengths were similar, but the absorbance of the former was slightly higher than that of the latter. 6) The quantity of the sericin measured by the colorimetric analysis, turned out to be less than by the Kjeldahl method. 7) Both temperature and duration in the cocoon cooking process has much effect on the swelling and solubility of the cocoon shells, but the temperature was more influential than the duration of the treatment. 8) The factorial relation between the temperature and the duration of treatment of the cocoon cooking to check for siricin swelling and solubility showed that the treatment duration should be gradually increased to reach optimum swelling and solubility of sericin with low temperature(70$^{\circ}C$) . High temperature, however, showed more sharp increase. 9) The more increased temperature in the drying of fresh cocoons, the less the sericin swelling and solubility were obtained. 10) In a specific cooking duration, the heavier the cocoon shell is, the less the swelling and solubility were obtained. 11) It was considered that there are differences in swelling or solubility between the filaments of each cocoon layer. 12) Sericin swelling or solubility in the cocoon filament was decreased by the wax extraction.. 13) The ionic surface active agent accelerated the swelling and solubility of the sericin at the range of pH 6-7. 14) In the same conditions as above, the cation agent was absorbed into the sericin. 15) In case of the increase of Ca ang Mg in the reeling water, its pH value drifted toward the acidity. 16) A buffering action was observed between the sericin and the water hardness constituents in the reeling water. 17) The effect of calcium on the swelling and solubility of the sericin was more moderate than that of magnecium. 18) The solute of the water hardness constituents increased the electric conductivity in the reeling water.

• Journal of Sericultural and Entomological Science
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• v.15 no.2
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• pp.55-60
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• 1973

The statistical interpretations are on the correlations and the linear regressions between the various meteorological conditions the branch Pusan-Observatory of the National-Central-Meteorological-Observatory had measured from 1930 to 1962, and the production of silk worm cocon that the Section of Sericulture in the Ministry of Agriculture ＆ Fishery had recorded from 1930 to 1962 in Gyung Sang Nam Do Korea. These were most in proportion to the sun shine time, an inverse proportion to the atmosphere humidity and the lowest temperature, in proportion to the mean temperature, the highest temperature and the amount of the rain fall. The correlations and linear regressions between the various meteorological factors to control the production of the silkworm cocoon of both per a box of the silk worm egg and per 10a of mulberry field was as follows. (1) The production of the spring silk worm cocoon was dicided by the various meteorological factors. 1. This was in proportion to the total sun shine time between 5 and 6 month. r=0.40＊-(0.42$^{**}$) Y=0.0269$\chi$＋6.46-(0.2795$\chi$＋10.25) 2. This was an inverse proportion to the total amount between 5 and 6 month atmosphere humidity. r=-0.49$^{***}$-(-0.40＊) Y=-0.2989$\chi$＋62.77-(0.1474$\chi$＋31.86) 3. This wasin proportion to the total rain fall amount between 6 and 7 month. r=0.47$^{***}$-(0.44$^{***}$) Y=0.0037$\chi$＋16.42-(0.0035$\chi$＋8.35) (2) The production of the autumn silk worm cocoon was decided by the various meteorological factors. 1. This was in proportion to the total sun shine time between 5 and 6 month. r=0.37＊-(0.45$^{***}$) Y=0.0205$\chi$＋5.51-(0.0173$\chi$＋2.41) 2. This was an inverse proportion to the total amount between 5 and 6 month atmosphere humidity. r=-0.41$^{**}$-(-0.42$^{**}$) Y=-0.2085$\chi$＋45.33-(-0.0599$\chi$＋12.17) 3. This was in proportion to the total of rain fall amount of 6 and 7 month. r=0.48$^{***}$-(0.35＊) Y=0.0050$\chi$＋11.97-( ) 4. This was in proportion to the total sun shine time among 3, 4, 5, and 6 month. r=0.51$^{****}$-(0.49$^{***}$) Y=0.0178$\chi$-1.27-(0.0096$\chi$-3.60) 5. This was an inverse proportion to the total amount among 3, 4, 5, and 6 month atmosphere humidity r=-0.41/$^{**}$-(-0.44$^{***}$) Y=-0.0938$\chi$＋40.14-(-0.05693$\chi$＋20.49) 6. This was in proportion to the total of a year sun shine time. r=0.58$^{****}$-(0.43) Y=0.0037$\chi$＋5.35-(0.0015$\chi$＋1.02) (3) The production of the next year spring silk worm cocoon was decided by the this year various meteorological factors. 1. This was in proportion to the total of a year sun shine time. r=0.55$^{****}$-(0.52$^{****}$) Y=0.0034$\chi$＋12.02-(0.0025$\chi$＋3.84).>＋3.84).3.84).>＋3.84).