• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.4 no.4
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• pp.399-405
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• 1991

The interaction of 4 dietary crude protein (13, 16, 19 or 22%) and 4 metabolizable energy (2600, 2800, 3000 or 3100 kcal ME/kg) levels on egg quality performances of Starcross layers were assessed between 245 and 275 days of age. The egg weight increased significantly with the increasing dietary protein and energy levels. But egg shape index, albumen index, yolk index, yolk dry matter, yolk protein, yolk fat, albumen protein and shell tickness were similar at all dietary protein and/or energy levels. The egg specific gravity and albumen weight increased but the yolk, weight, Haugh unit and albumen drymatter decreased with the increase of dietary protein levels and showed irregular trend with energy levels. The albumen dry matter and egg shell weight, however, were not affected by energy and protein levels. Simultaneous increase of protein and energy increased specific gravity, albumen index and shell thickness at a greater rate than that increased by the increase of protein or energy alone.

• Korean Journal of Poultry Science
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• v.27 no.2
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• pp.133-153
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• 2000

The egg's interior quality is one of the most important criteria for commercial producers and consumers. Internal quality is complex, including aesthetic factors such as taste, freshness, nutritional and processing values, and the genetic influences upon these upon these factors ranges from none to considerable. The rate of cholesterol synthesis in the hen is very high compared to other animals and humans. Genetic selection, diet drugs and other chemicals can alter cholesterol concentration in the plasma of laying hen, but attempts to manipulate the cholesterol concentration in the egg yolk are generally unsuccessful since the cholesterol can only be changed to a small extent. Factors which may affect the degree of pigmentation of the yolk include the type of xanthophyll and its concentration in the feed, the feed composition, and the health of the hen. Several feed ingredients interact with carotenoid pigment to improve or reduce their deposition rates in yolks. Egg weight is determined by genetics, body size prior to first egg housing density, environmental temperature, lighting program, total feed consumption, calcium, phosphorus, niacin, water, methionine, total sulfur amino acids, energy, linoleic acid, fat and protein levels. Eggs need to be promote levels. Eggs need to be promoted a versatile commodity and new processed egg items need to be developed. Organic eggs are laid by hens which were raised in chemical and drug frdd environments. There are still difficulties in producing these eggs due to the availability of organic poultry feeds and cost of organic grains.

• Korean Journal of Poultry Science
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• v.26 no.3
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• pp.203-211
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• 1999

This study was performed to develop brand egg. Forty-four week-old Isa Brown were randomly assigned to 8 treatments and the number of hens were 300 per each group. Experimental period was about 10 weeks. The 8 treatment were as follows : astarich 2%(A), astarich 5%(B), chitch chitosan 2%(C), omega-3 powder 2%(D), pyrogreen 1%(E), greenpia 0.2%(F), hydrogenated soy oil 3%(G) and commercial layer feed(H). Eggs were collected at day 0, 7, 14, 40 and 70 for egg quality analyses. Laying rate was significantly higher in astarich groups(B, C) than ant other group, showing average of 88% of laying rate. In terms of egg factors, whole egg weight was the heaviest in control in control(A) and the lightest in omega-3 powder group(E), while egg yolk weight was the heaviest in astarich group(H). Haugh unit(HU) was the mean of 70 for all treatments and there were no significant differences among the treatments. Egg yolk color was significantly different among treatments during experimental period whenever yolk color was measured. At the day 7 after feeding of experimental diets, the yolk color of astarich 5% group(C) was darker and that of omega-3 powder group(E) lighter. The value of yolk color in astarich 5%(C) and 2%(B) was 14.2 and 12.5, respectively. But the rest of the groups did not show any differences in yolk color, showing mean of 11.5. In terms of shell thickness, shell tended to become thinner, but there were no defferences among treatments during experimental period. The mean value of shell thickness was 0.390mm. In conclusion, astarich groups may seem to produce the best possible quality of brand egg.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.3
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• pp.391-397
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• 2015

Two hundred and sixteen Institut de S$\acute{e}$lection Animale (ISA) brown layers (40 wks of age) were studied for 6 wks to examine the effect of microalgae powder (MAP) on egg production, egg quality, blood lipid profile, and fatty acid concentration of egg yolk. Dietary treatments were as follows: i) CON (basal diet), ii) 0.5% MAP (CON+0.5% Schizochytrium powder), and iii) 1.0% MAP (CON+1.0% Schizochytrium powder). From 44 to 46 wks, egg production was higher in 1.0% MAP treatment than in control treatment (linear, p = 0.034); however, there was no difference on the egg production from 40 to 43 wks (p>0.05). Serum triglyceride and total cholesterol were significantly reduced in the groups fed with MAP, compared to those in groups fed with control diets (Quadratic, p = 0.034 and p = 0.039, respectively). Inclusion of 0.5% MAP in the diet of layers improved egg yolk color, compared with hens fed with basal diet at 46 wks (quadratic, p = 0.044). Eggshell thickness was linearly increased in MAP-fed treatments at 46th wk (p<0.05). Concentration of yolk docosahexaenoic acid (DHA; C22:6n-3) was increased in treatment groups fed with MAP (linear, p<0.05). The n-6 fatty acids, n-6/n-3 fatty acid, and unsaturated fatty acid/saturated fatty acid were decreased in treatment groups fed with MAP (linear, p<0.05). These results suggest that MAP improved the egg production and egg quality, and may affect serum lipid metabolites in the layers. In addition, MAP increases yolk DHA levels, and deceases n-6/n-3 fatty acid ratio.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.6
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• pp.835-840
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• 2005

The main objective of the present study was to determine the effect of dietary $\beta$-cyclodextrin ($\beta$-CD) on egg laying performance and cholesterol content of egg yolk. Feed intake, egg production and egg weight varied slightly, but not significantly, between hens fed either a control diet or a diet containing one of an increasing series of $\beta$-CD concentrations (2%, 4% or 6%). However, feed intake, egg production and egg weight were all lower in the hens fed on 8% $\beta$-CD (p<0.05). No difference in haugh unit values, egg yolk color and egg shell thickness were found between the different treatments. The cholesterol content of egg yolks (mg/g yolk) was significantly decreased by 0.71, 2.98, 4.00 and 4.24 mg in eggs from hens maintained on 2%, 4%, 6% and 8% $\beta$-CD, respectively (p<0.05). These observations indicate that appropriate supplementation of diets with $\beta$-CD can reduce the cholesterol content of eggyolks, thus raising the prospect of the production of a healthier functional food.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.3
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• pp.417-423
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• 2017

Objective: This experiment investigated the effects of dietary supplementation with conjugated linoleic acid (CLA) on the serum components, laying hen productivity, lipid composition of egg yolk, egg flavor and egg quality. Methods: Healthy 28-week-old Hy-Line white laying hens (n = 480) were divided randomly into 4 groups, 6 replicates/group, 20 birds/replicate. The 30-day experimental diets included 0% (control), 0.4%, 0.8%, and 1.6% CLA. Some serum indices of the birds, and egg production, quality, fatty acid composition, egg quality were measured. Results: The dietary supplementation with 0.4%, 0.8%, and 1.6% CLA did not significantly affect the laying rate and feed intake, as well as calcium ion and phosphorus ion concentration in serum (p>0.05). However, the CLA had significantly increased the strength of eggshell, decreased the odor, flavor, and taste of egg yolk, deepened the color of egg yolk, increased saturated fatty acids and polyunsaturated fatty acids, and reduced the monounsaturated fatty acids (p<0.05). On the other hand, the dietary supplementation with 1.6% CLA had significant effects on feed/gain, and improved serum hormones. Dietary supplementation with 0.4% and 0.8% CLA can significantly enhance the activity of alkaline phosphates. Conclusion: CLA has no effect on production performance, but does enhance the lipid content of the egg yolk and the strength of the eggshell.