• Korean Journal of Poultry Science
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• v.35 no.3
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• pp.275-281
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• 2008

This experiment deals with lycopene-enriched egg production in chicken and their effects on egg quality, especially antioxidant status of eggs upon their long term storage. Forty two laying hens(Hyline, 36 weeks of age) were assigned randomly to 1 of 2 diets containing 0 mg and 2 mg lycopene per kilogram feed for 4 weeks. There was a comparable concentration of lycopene in egg yolk($1.57{\mu}g$/1 g yolk) of chickens supplemented with dietary lycopene. No measurable concentration of lycopene was detected in egg yolk of chickens fed the control diet. Dietary lycopene supplementation increased egg yolk color(P<0.01), egg yolk height(P<0.08), egg yolk diameter(P<0.19), egg shell intensity(P<0.19), egg white height(P<0.33), and Haugh unit (P<0.34). After 4 week of storage of eggs in room temperature, lycopene treated eggs were tested for freshness. The ESI, EYH, EWH, HU, and EYC of lycopene treated eggs were comparably higher than those of control groups, even though there was not statistically significant difference between two groups whereas EYD of the control group was smaller than that of lycopene treated group. In conclusion, dietary lycopene supplementation to chickens might be improved egg quality.

• Korean Journal of Poultry Science
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• v.43 no.4
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• pp.253-261
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• 2016

Egg quality is a very important factor for both consumers and producers. Factors affecting egg quality include strain and age of hens; egg storage temperature, time, and humidity; laying season; and feeding. This study aimed to determine the effect of hen age and egg storage time on egg quality. A total of 700 eggs obtained from Hyline Brown commercial layers were used for this experiment, and they were separated into two hen age groups (30 vs. 60 weeks) with eight treatments and four storage times (day 0, 10, 20, and 30). The egg weight; shell color, thickness, and density; albumen height; Haugh unit (HU); yolk color; and the yolk and albumen pH and viscosity were measured for the egg quality assessment. The results showed that the age of the hen and egg storage time significantly affected almost all parameters of the internal and external egg quality. The shell thickness, albumen height, HU, yolk color, pH of yolk and albumen, and yolk viscosity significantly decreased with increasing hen age. The egg shell color was significantly lighter in eggs from 60-week-old hens than in those from 30 weeks-old hens. The egg weight; shell weight, thickness, and density; albumen height, HU; and albumen viscosity significantly decreased, but the yolk color and pH of the yolk and albumen increased with increasing egg storage time. The interaction effects between the storage time and hen age were significant in shell thickness, albumen height, yolk color, and yolk and albumen pH and viscosity. The eggs obtained from 60-week-old hens showed significantly lower shell thickness, albumen height, and HU values, which are considered typical egg quality measurements, than values of eggs from 30-week-old hens. Therefore, increasing hen age and egg storage time caused the deterioration of egg quality. In conclusion, this study demonstrated that hen age is the major factor affecting the quality of fresh eggs, whereas the storage time is the determinant factor affecting the quality of stored eggs.

• The Korean Journal of Food And Nutrition
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• v.15 no.4
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• pp.350-356
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• 2002

This study was carried out to investigate the effect of bovine plasma for the preparation of mayonnaise on quality characteristics through the tests of viscosity, color, emulsion stability and sensory evaluation. In the case of standard mayonnaise preparation with the bovine plasma addition from 0.01% to 0.1%, The result of viscosity, color, emulsion stability and acceptability are improved. When the bovine plasma(5%) was only used to Prepare mayonnaise without e99 yolk, the result of color and acceptability were reduced, whereas viscosity, emulsion stability were observed as the characteristic of standard mayonnaise. The sample mayonnaise containing the e99 yolk(50%) and bovine Plasma (0.5～1.0%) was observed as the characteristics of standard mayonnaise without color.

• Korean journal of food and cookery science
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• v.17 no.1
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• pp.7-12
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• 2001

Yackwa was prepared by different amounts of egg yolk and then instrumental characteristics and sensory evaluation were investigated during storage periods. In texture profile analysis, hardness, gumminess and chewiness of Yackwa were increased during storage and texture parameters were increased by increasing egg yolk level. In Hunter's color value, lightness and redness were increased by increment of egg yolk level, whereas. yellowness was increased in negative region. During storage all values were increased. In the results of sensory evaluation, crispiness and overall acceptance were significantly different during storage and other parameters didn't showed significant difference among samples. The results showed that Yackwa prepared with 20g of egg yolk had good sensory quality and nutritious improvement.

• Korean Journal of Poultry Science
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• v.29 no.1
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• pp.19-23
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• 2002

This studs was conducted to investigate the effects of dietary carbohydrase (multi-enzyme: $\alpha$-galactosidase and mannanase) on egg quality and nutrient digestibility in laying hens. One hundred forty four, 47-wk-old, ISA Brown commercial layers were used in a 28-d feeding trial after a 7-d adjustment period. Dietary treatments were 1) CON(basal diet), 2) ME 0.1 (basal diet +0.1% multi -enzyme), 3) ME 0.2 (basal diet + 0.2% multi-enzyme). Fer overall Period, hen-day egg Production, egg weight, egg shell breaking strength and egg shell thickness were not influenced by the multi-enzyme. As the adding levels of multi-enzyme increased in the diet, egg Yolk color and egg Yolk index tended to increase with significant differences. Digestibility of DM was not affected by multi-enzyme. However, digestibility of N increased significantly as the concentration of multi-enzyme in the diet was increased. In conclusion, supplemental carbohydrase in laying hen diets nay have some roles in improving the egg Yolk color and N digestibility.

• Korean Journal of Poultry Science
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• v.34 no.3
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• pp.181-185
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• 2007

This study was conducted to evaluate the effects of dietary delta-aminolevulinic acid (ALA) on egg production and egg quality in laying hens. A total of 114 (30-wk age) ISA brown commercial hens were used in current trial for 28 days. Dietary treatments included 1) CON (basal diet), 2) 0.05 (basal diet + ALA 0.05%), 3) 0.1 (basal diet + ALA 0.1%) and 4) 0.2 (basal diet + ALA 0.2%). There were four dietary treatments with four replication per treatment and twelve laying hens per replication. During the overall period, egg production was quadratically affected (P=0.01) by ALA supplementation compared with control treatment. Egg weight increased (linear effect, P=0.01; quadratic effect, P=0.01) as the level of delta-aminolevulinic acid supplementation increased in the diets. Yolk color was increased quadratically (P=0.03). The difference of hemoglobin concentration was increased (quadratic effect, P=0.01) as the level of delta-aminolevulinic acid supplementation increased in the diets. In conclusion, the results of the experiment suggest that dietary delta-aminolevulinic acid could affect egg weight, yolk color and hemoglobin concentration in laying hens.

• Korean Journal of Organic Agriculture
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• v.22 no.4
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• pp.815-823
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• 2014

Green tea has been known to show beneficial effects on alleviating stress. The present study was conducted to determine the effects of dietary green tea on quality of eggs, during storage, laid by laying hens treated with corticosterone in order to mimic the current practice of the egg market. Hens were fed for 2 weeks one of three diets containing green tea at 0.0, 0.4 or 1.0%. Each dietary group was divided into two subgroups receiving corticosterone at 0 or 30 mg/kg for 1 week. Eggs, laid at 5-7 days following the initiation of corticosterone treatment, were stored at $10^{\circ}C$ for 1 or 5 weeks and then analyzed for egg quality. After 1 week of storage, egg weight was significantly increased by green tea (p<0.025) but decreased by corticosterone (p<0.0001), but no interaction was observed between both. Corticosterone decreased shell color (p<0.0001) but green tea significantly decreased shell strength (p<0.006). Yolk color, albumen height and Haugh unit were not affected by both treatments. After 5 weeks of storage, corticosterone resulted in reduced egg weight (p<0.01) and eggshell color (p<0.001) and increased shell strength, which were not attenuated by green tea. Taken together, the results of the current study show that dietary corticosterone reduces egg quality during storage, which are attenuated in part by dietary green tea.

• Culinary science and hospitality research
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• v.20 no.1
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• pp.65-75
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• 2014

This study prepared steamed eggs at various ratios of yolk and white in packaged liquid eggs to investigate the quality characteristics of steamed eggs through sensory tests and analyses of water content, color, pH and texture profiles. The results are expected to be used in developing steamed egg products and preparing processed egg dishes. Moisture contents of steamed egg samples increased with increased percentage of egg white. Hunter color values of L(lightness) also increased with increased percentage of egg white, while a(redness) and b(yellowness) decreased. Moreover, pH increased with increased percentage of egg white. Texture profile analyses in hardness, springiness, chewiness, gumminess, and cohesiveness decreased significantly with increased percentage of white, but adhesiveness was not significantly different. As the results of sensory test, yellowness increased with increased percentage of yolk. Roasted nutty smell was highest in the steamed egg sample prepared with 250g yolk and 200g white, and fishy smell increased and boiled egg smell decreased with increased percentage of white. Roasted nutty taste and fishy taste increased with increased percentage of white. In contrast with brittleness, hardness, springiness, and chewiness decreased with increased percentage of egg white. The acceptance score was high in the steamed egg samples prepared with a ratio of egg yolk 250/egg white 200 or egg yolk 150/egg white 300.

• 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.

• Journal of Life Science
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• v.23 no.2
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• pp.237-241
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• 2013

To evaluate the effects of anthocyanin-fortified barley (AFB) and whole crop barley (WCB) addition to diets, 200 Brown Nick hens were assigned to 5 treatments with 5 replicates for 8 weeks. All the treated groups differed in feed intake, egg production, egg weight, and egg mass compared to those of a control group. As the intake of barley was increased, feed intake, egg production, and egg mass decreased. In terms of egg quality, the yolk color (YC), the egg shell breaking strength (SBS), and the egg shell color (SC) differed up to 6 weeks of growth. Feeding the WCB and AFB to laying hens up to 8 weeks had a positive influence on albumin height (AH) and the haugh unit (HU). Up to 6 weeks of growth, increasing the amount of barley in the diets of the laying hens had a positive effect on the SC and the YC but had no effect on the SBS. Diets including 20% AFB and WCB increased the AH and HU to 9.10 and 94.53, respectively. The results suggest that the addition of AFB and WCB up to 10% to the diets of laying hens could improve the laying performance and the egg quality.