• Korean Journal of Poultry Science
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• v.7 no.2
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• pp.47-53
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• 1980

This study was carried out to investigate the variations in the thickness of egg shell and egg shell membrane of Quail eggs from July 25, 1978 to September 7, 1978. No. of eggs used in this experiment was 520 okay and all the eggs were purchased from a farm located in Jinju city. The results obtained are summarized as follows: 1. Egg shells of quail were classified as white egg shell with large spots, egg shell with large spots, violet egg shell with small spots and beige egg shell with small spots by the exterior shell colour and their average egg weights were 8.993g, 8.866g, 8.403g and 8.109g, respectively. 2. Average egg shell thickness of white egg shell with large spots, egg. shell with large spots, violet egg shell with small spots and beige on shell with small spots were 0.171mm, 0.169mm, 0.160mm, and 0.156mm, respectively. 3. Average eggs shell membrane of white egg shell with large spots, egg shell with large spots, violet egg shell with small spots and beige egg shell with small spots were 0.0449mm, 0.0431mm, 0.0398mm, and 0.0397mm, respectively. 4. Negative correlation coefficient was found between egg shell thickness ana egg shell membrane thickness, but it was not significant. 5. Comparing quail egg with fowl egg, the thickness of quail egg shell was much thinner than that of fowl egg, but egg shell membrane thickness was similar between the two.

• 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.

• Food Science of Animal Resources
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• v.37 no.4
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• pp.571-578
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• 2017

This study aimed to determine the optimal ratio of natural calcium powders (oyster shell and egg shell calcium) as synthetic phosphate replacers in pork products. Ground pork samples were subjected to six treatments, as follows: control (-) (no phosphate added), control (+) (0.3% phosphate blend added), treatment 1 (0.5% oyster shell calcium powder added), treatment 2 (0.3% oyster shell calcium powder and 0.2% egg shell calcium powder added), treatment 3 (0.2% oyster shell calcium powder and 0.3% egg shell calcium powder added), and treatment 4 (0.5% egg shell calcium powder added). The addition of natural calcium powders resulted in an increase in the pH values of meat products, regardless of whether they were used individually or mixed. The highest cooking loss was observed (p<0.05) in the negative control samples, whereas the cooking loss in samples with natural calcium powder added was similar (p>0.05) to that in the positive control samples. CIE $L^*$ values decreased as the amount of added egg shell calcium powder increased. CIE $a^*$ values were higher (p<0.05) in samples containing natural calcium powder (treatments 1, 2, 3, and 4) than in the positive control. The combination of oyster shell calcium powder and egg shell powder (treatment 2 or 3) was effective for the improvement of textural properties of the pork products. The findings show that the combined use of 0.2% oyster shell calcium and 0.3% egg shell calcium should enable the replacement of synthetic phosphate in the production of cooked pork products with desirable qualities.

• Korean Journal of Agricultural Science
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• v.29 no.1
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• pp.44-54
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• 2002

The fresh eggs of African ostrich in Korea were used in this study to investigate their interior and exterior quality characteristics. In ostrich egg shape characteristics, long and short length were measured as 15.1~16.1 cm and 12.1~13.6 cm, respectively. The egg shape index was calculated as 81.0 and the egg shell showed a more g loss white in color than that of hen egg. Calculated breaking strength of egg shell and egg shell surface based on the equation were $41.155kg/cm^3$ and $804.7cm^2$, respectively. Average egg shell thickness including egg shell membrane was 1.89 mm and there are no differences among parts of the shell. The egg shell membrane thickness was 0.10 mm showing relatively thick in equator compared with that of blunt end. The ave rage number of egg shell pores was counted as $19.7/cm^2$ showing relatively high number of egg shell pores at point end and the total number of egg shell pores in an egg was estimated as 15,241. The relative port ion of each parts based on egg weight was estimated as 25.1% for egg yolk, 58.2% for egg white, 16.7% for egg shell and the ratio of egg yolk to egg white (Y/W) was 0.43. The average diameter and the ave rage height of ostrich egg white were 19.7 cm and 13.2 mm, respectively. Calculated the H.U (Haugh Unit) was -69.7 and the pH was 8.3. In ostrich egg yolk, the diameter, the height, the egg yolk index, and it's pH were calculated as 14.4 cm, 29.4 mm, 0.20, and 6.6, respectively. And the egg yolk color showed a more thin in yellow chroma compared with that of hen egg as due to it's thicker membrane.

• Korean Journal of Organic Agriculture
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• v.24 no.1
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• pp.115-122
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• 2016

The main purpose of the current study was to compare quality of eggs 1) produced from hens housed in battery cages vs. free range, 2) from young vs. old hens, and 3) tagged with the lowest vs. the highest price in a local franchised mart. The ages of hens, at which their eggs were used for the analysis of quality, were 70 weeks old in the experiment 1, 22 and 47 weeks old in the experiment 2, and were unknown in the experiment 3. Eggs were analyzed for weight, albumen height, Haugh unit, shell color, shell strength, shell thickness, shell weight, yolk color, yolk weight, and egg white weight. In the experiment 1, significant differences were detected between two housing systems in shell color, shell weight, yolk color, and yolk weight (P<0.05), but not in egg weight, albumen height, Haugh unit, shell strength, shell thickness, and egg white weight (P>0.05). Although egg weight was slightly but not significantly higher in battery cages by 2.2 g than in free range, yolk weight was significantly higher in battery cage (P<0.05). On the contrary, shell color was greatly increased in free range system by 68.5% compared with battery cage. In the experiment 2, there were significant differences between young and old hens in egg weight, albumen height, Haugh unit, shell strength, shell weight, yolk color and yolk weight (P<0.05). Egg weight, shell weight, yolk color and yolk weight were increased in old hens than young hens while albumen height, Haugh unit, and shell strength were decreased. In the experiment 3, egg weight, albumen height, Haugh unit, shell weight, and egg white weight were significantly higher in the highest priced eggs than the lowest ones (P<0.05), whereas shell strength and yolk color were lower (P<0.05) but shell color, shell thickness and yolk weight were not different (P>0.05). So, egg freshness was clearly higher in the highest priced ones than in the lowest (P<0.05). Due to the limited information on raising and husbandry of laying hens whose eggs were tested for egg quality in the current study, the present results should be cautiously interpreted while contributing to the future study as a basis in this field.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2002.11a
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• pp.140-142
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• 2002

This study was conducted to obtain some genetic information for developing superior Korean native chickens. Heterosis and combining ability effects were estimated with 1,080 progenies of full diallel crosses of 3 strains in Korean Native Chicken. The traits of egg productivity were Investigated, and heterosis effect, general combining ability, specific combining ability and reciprocal effect were analyzed model I of the Griffing's method 1. The general performance were 147.0 days in age at first egg laying, 71.8 eggs in egg numbers to 270 days, 50.1g in egg weight at 270 days, 75.6 in egg shape index, 356$\mu\textrm{m}$ in egg shell thickness, and 4.27kg/$\textrm{cm}^2$ in egg shell strength, respectively. According to result, heterosis effect revealed comparatively high in age at first egg laying, egg numbers, egg weight, and egg shell strength. The effects estimated highly in general combining ability for age at first egg laying, egg numbers, egg weight, egg shape Index and egg shell thickness, and in specific combining ability were egg numbers, egg weight and egg shell thickness, and in reciprocal effects for egg numbers, egg shape index, and egg shell thickness. This result could be used for developing Korean native chicken.

• Korean Journal of Poultry Science
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• v.43 no.1
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• pp.31-38
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• 2016

Consumers demand fresh and high-quality eggs. Egg quality may be represented by shell color, shell weight, egg weight, shell thickness, shell density, albumen height, yolk color, albumen pH and viscosity. Various factors such as strain, age of hen, storage temperature, humidity, the presence of $CO_2$ and storage time affect egg quality. Therefore, we investigated the effects of storage time and temperature on egg quality to define the freshness of Korean market eggs. A total of 1,800 eggs were used for this experiment and were separated into 45 treatments with 40 eggs in each. The treatments were consisted of 15 storage periods (2 d to 30 d) and 3 storage temperatures ($2^{\circ}C$, $12^{\circ}C$, $25^{\circ}C$). Each egg was weighed and broken, and the height of the thick albumen, Haugh units (HU), egg shell color and yolk color were measured by a QCM+system. We also observed the physiochemical properties of eggs such as yolk pH, albumen pH and albumen viscosity. The egg weight, shell weight, albumen height, HU and albumen viscosity significantly decreased with increasing storage time and temperature. However, the albumen and yolk pH significantly increased with increasing storage period and temperature. The interaction effects between the storage period and temperature were significant for shell weight, shell density, egg weight, albumen height, HU, yolk color, yolk pH, albumen pH and albumen viscosity. In the analysis of the correlation with egg quality, the storage temperature exhibited a higher correlation coefficient than the storage period. In conclusion, storage time and temperature are the major factors affecting egg quality, but the storage temperature is a more sensitive determinant of egg quality deterioration compared with the storage period.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.33-34
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• 2022

The purpose of this study was to provide basic data for applying oyster shells and egg shells as fireproof cladding materials by substituting fine aggregates for oyster shell powder and egg shell powder, and comparing strength and fire resistance performance. The reason for the high strength was thought to be that the oyster shell had higher strength than the egg shell itself, and both ESP and OSP were measured at a backside temperature of less than 500℃, so it was judged that it could be used as a fireproof coating for steel structures.

• Korean Journal of Poultry Science
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• v.10 no.1
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• pp.23-29
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• 1983

This study was carried out to investigate the variabilities of the thickness of egg shell and shell membrane of silky fowl egg from April 11, 1983 to May 14, 1983. One hundred and twenty eggs used in this experiment were obtained from a Synanmyun silky fowl farm, Sanchungkun, Gyeongnam province. The results obtained are summarized as follows: 1. Total items investigated for the silky fowl egg; egg weight, egg shell weight, egg shell thickness of sharp end, middle part, and blunt end, egg shell membrane thickness of snarp end, middle part, and blunt end, breaking strength, length of egg(L), width of egg(W), and L/W, were measured as 36.58${\pm}$0.446g, 4.53${\pm}$0.079g, 0.32${\pm}$0.006mm 0.32${\pm}$0.047mm, 0.30${\pm}$0.056mm, 0.050${\pm}$0.001mm, 0.050${\pm}$0.001mm, 0.053${\pm}$0.001mm, 3.06${\pm}$0.101kg, 4.80${\pm}$0.024mm, 3.82${\pm}$0.010cm, and 1.26${\pm}$0.005, respectively. 2. Correlation coefficients among 66 combinations of 12 items were estimated. The correlation coefficients relating to egg weight, egg shell weight, egg shell thickness of sharp end, middle part, and blunt end breaking strength, length of egg (L), width of egg (W), and L/W were largely to be highly significant but those related egg shell membrane thickness of sharp end middle part, and blunt end were not significant, sometimes showing inverse correlation

• Korean Journal of Poultry Science
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• v.25 no.3
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• pp.103-111
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• 1998

This study was carried out to estirnate the heritabilities and genetic correlations on egg shape index and internal egg qualities ; shell thickness, alburnin heights and Haugh units for breeding plan and selection in Korean native chicken. Data analyzed were the records of 46,908 eggs from 43() layers from April, 1994 to September, 1995. The egg shape index at the first egg, 300 days and 500 days of ages were 74.771, 74.468 and 73.702; the shell thickness were 0.345, 0.344 and 0. 334mm; the alburnen heights were 6.579, 6.130 and 5.318mm; the Haugh units were 86.859, 81.014 and 73.565 respectively. The heritability estimates of egg shape index and internal egg qualities based on the variance of sire, dam and combined components at 300 days of age were 0.136, 0.954 and 0.545 for egg shape index; 0.201, 0.622 and 0.421 for shell thickness; 0.410, 0.961 and 0.633 for albumen height ; 0.353, 0.962 and': 0.608 for Haugh units. The genetic correlation coefficient between shell thickness and albumen height was -0.044~0.824; 0.016~0.949 between Haugh units and shell thickness 0.313~0.941 between albumen height and Haugh units, respectively.