• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.1
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• pp.25-31
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• 1988

The crude calcium acetate (CCA) was made from egg-shell and acetic acid to use the CCA as a coagulant for Tofu (soy bean curd). Amount of CCA. $CO_2$ and residue made from 5.6g egg-shell (average weight of a egg-shell) and 10% acetic acid(50m1) was 3.8g, $300{\pm}10ml(at\;25^{\circ}$ and 2.1g. respectively. Tofu formable minimum concentration of the CCA was about 0.14% similar to that of $CaCl_2$, $MgCl_2$. Volume, hardness, taste and content f protein and lipid of Tofu by addition of CCA were not significantly different in those of Tofu that magnesium chloride and calcium chloride were used.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2004.11a
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• pp.101-102
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• 2004

The observed means and standard divisions of the egg texture per generation in korean native chickens were as follow. The egg shell strength, the egg shell thickness and the egg shell colour were 3.8$\pm$0.2~4.2$\pm$0.1 kg/$\textrm{cm}^2$, 356.4$\pm$4.9~368.8$\pm$6.5${\mu}{\textrm}{m}$ and 47.0$\pm$1.7~50.0$\pm$3.3％. The regression coefficients were -0.03~0.03 kg/$\textrm{cm}^2$, -0.84~4.40${\mu}{\textrm}{m}$ and -0.88~-0.36％ respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.7
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• pp.853-859
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• 2006

This study was carried out to investigate the effect of egg shell calcium salt types and egg shell membrane on calcium metabolism in rats. Sprague-Dawley male rats, 4 weeks of age, were fed on free-calcium diets for 2 weeks after adjustment period. Rats weighing approximately $247{\pm}2.3g$ were divided into 6 groups and were fed on the experimental diets containing 0.2% calcium for 4 weeks. Experimental groups were as follows; {ES(M+)} (egg shell powder diet with egg shell membrane), {ES(M-)} (egg shell powder diet without egg shell membrane), {AC(M+)} (egg shell calcium acetate diet with egg shell membrance), {AC(M-)} (egg shell calcium acetate diet without eg shell membrane), {GC(M+)} (egg shell calcium glucuronate diet with egg shell membrane) and {GC(M-)} (egg shell calcium glucuronate diet without egg shell membrane). Bone length of femur was significantly different by the types (p<0.05) of egg shell calcium salts. Bone mineral density of femur showed the highest level in AC(M-) group. Calcium content of femur and calcium absorption rate were higher in egg shell calcium salt groups than in eg shell powder groups. Calcium absorption rate and retention were significantly different (p<0.05) among the types of eg shell calcium salts and were higher in the AC(M-) group than in the other groups. Alkaline phosphatase activity, parathyroid hormone and osteocalcin levels of serum showed no significant difference among the experimental groups. From the above results, it is concluded that bioavailability of calcium is higher in groups of egg shell calcium salts compared to those in egg shell powder, even though egg shell membrane has no effect on calcium metabolism. Thus, these findings suggest the possibility of using egg shell calcium salts as a functional food material related to calcium metabolism.

• KOREAN POULTRY JOURNAL
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• v.40 no.6 s.464
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• pp.152-153
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• 2008

갈색난의 색이 옅으면 상품가치를 저하시켜 난가에 영향을 주게 된다. 닭은 빛에 의해 비타민 D를 체내 합성을 할 수 있으므로, 고농도의 비타민 D3수준을 유지하면서 자외선에 노출 될 경우 독성으로 난각 색이 옅은 알을 산란하게 된다. 기존의 비타민 D3양을 공급하더라도 자외선에 노출 되지 않을 경우 난각 색은 정상으로 돌아온다. 산란 계의 간에서 비타민 D3독성은 난각 색 저하의 주된 원인으로 꼽히므로 사료 내 비타민 D 함량은 항상 일조량을 염두에 두고 결정 해야 한다.

• KOREAN POULTRY JOURNAL
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• v.42 no.5
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• pp.110-115
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• 2010

국민들의 소득수준이 높아지면서 계란을 선택할 때에도 가격이 다소 비싸더라도 품질을 믿을 수 있는 계란을 구매하는 비율이 높아지고 있으며, 실제로 기능성 계란 등 특수란의 매출이 늘고 있는 추세다. 일반란을 구매할 때에도 품질을 따지는 소비자가 늘어나면서 계란판매에 어려움을 겪지 않으려면 품질이 좋은 계란을 생산해야 한다. 계란의 난각과 난질은 물로 신선도가 떨어지면 소비자의 외면으로 상인들이 기피하게 될 것이다. 특히 난각이 나쁠 경우 난질을 좋게 유지하기가 어렵고, 소비자가 계란을 선택할 때 내용물을 확인할 수 없으므로 눈으로 외형을 보고 선택하게 된다. 난각을 좋게 하여 파란 및 등외란을 줄인다는 것은 농장의 경영이익을 높이는 매우 중요한 관리사항이다. 난각을 좋게 하는 방법과 파란 및 등외란을 줄이는 여러 방법을 살펴보고자 한다.

• Korean Journal of Poultry Science
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• v.44 no.1
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• pp.19-28
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• 2017

The eggshell is an intricate and highly ordered structure composed of multiple layers and a calcified matrix. The eggshell is formed at the uterine segment of the chicken oviduct. In this study, histological changes in the uterine endometrium and the expression of the eggshell-related genes were investigated according to hen age. We analyzed the expression of eggshell protein-related genes, such as OCX-32, OCX-36, OC-17, OC-116, and eggshell-ion-related genes, such as CABL-1, SPP1, SCNN1G, ATP2A2, CA2, and CALM1. In chicken uterine endometrium, histological deformation, fibrosis, atrophy and elimination of micro-villi were found with increasing hen age. The concentration of blood-ion components did not significantly change with age. The amount of telomeric DNA in uterine endometrial cells decreased with increasing hen age. The expression of most of the eggshell-related genes changed significantly with increasing hen age. The expression of some ovo-proteins, which play a role in eggshell formation, increased with increasing hen age; however, there were no significant correlations among eggshell protein genes. Eggshell ion-related genes, such as ATP2A2, SCNN1G, CA2, and CALM1, were closely related to each other. The OCX-32 and OCX-36 genes were closely related to some of the eggshell ion genes. Eggshell protein-related genes, such as the OCX-32, OCX-36 genes and ion-related genes such as CALB-1, ATP2A2, SCNN1G, CA2, CALM1, affected eggshell formation, mutually or independently. This study shows that, uterine although endometrial cell damage occurs with increasing hen age, normal eggshells can be formed in old hens. This suggests that eggshell protein-and eggshell ion-related genes also control the homeostasis of eggshell formation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.18 no.2
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• pp.160-166
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• 1989

This study was conducted to investigate whether egg-shell may be used as a mineral sourceor leavening agent in breadmaking. In Korea the waste volume of egg shell has been estimated at about 28,694 tons per year. Carbon dioxide generation maxima were established for barking powder$(153{\pm}3ml/g)$, egg-shell(205in reaction with lactic acid) and yeast$(115{\pm}3ml/sugar\;g)$. Gas release time required for each substance to reach $CO_2$ maximum was, for baking powder 7 minutes, for egg-shell 45 mins and for yeast 240 mins. Particle size of egg-shell in breadmaking was suitable more than 20 mesh (-). When egg-shell only was added to the basic formular without including lactic acid, no leavening effect was observed. However, when lactic acid and egg-shell were used together, the leavening effect was more or less equivalent to that of yeast(control). Addition of egg-shell was found to increase calcium content of bread products without noticeable altering flavor, as compared with control. Joint use of egg-shell was organic acids in breadmaking was shown to have potential in time saving, volume increase and yeast saving.

• KOREAN POULTRY JOURNAL
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• v.24 no.1 s.267
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• pp.128-131
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• 1992

• KOREAN POULTRY JOURNAL
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• v.48 no.5
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• pp.164-166
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• 2016

• 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.