• Asian-Australasian Journal of Animal Sciences
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• v.28 no.4
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• pp.538-543
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• 2015

This experiment was conducted to measure the effects of olive leaf powder on performance, egg yield, egg quality and yolk cholesterol level of laying hens. A total of 120 Lohmann Brown laying hens of 22 weeks old were used in this experiment. The birds were fed on standard layer diets containing 0, 1%, 2%, or 3% olive leaf powder for 8 weeks. Egg weight and yield were recorded daily; feed intake weekly; egg quality and cholesterol content at the end of the trial. Olive leaf powder had no effect on feed intake, egg weight, egg yield and feed conversion ratio (p>0.05) while olive leaf powder increased final body weight of hens (p<0.05). Dietary olive leaf powder increased yellowness in yolk color (p<0.01) without affecting other quality parameters. Yolk cholesterol content was tended to decrease about 10% (p>0.05). To conclude, olive leaf powder can be used for reducing egg yolk cholesterol content and egg yolk coloring agent in layer diets.

• Journal of Environmental Science International
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• v.26 no.7
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• pp.869-874
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• 2017

This study was conducted to investigate the effects of dietary supplementation of various types of fermented red ginseng marc with red koji to laying hens on eggshell and egg yolk quality characteristics. A total of 240 Hy-line Brown laying hens (40 wk of age) were randomly allotted to 24 pens (6 replicates per treatment and 10 laying hens per replicate). Experimental diets consisted of 4 treatments containing basal diet (control), 1% fermented red ginseng marc powder with red koji, 1% fermented red ginseng marc pelleted with red koji and 1% fermented red ginseng marc coated with red koji. During the 8-wk feeding trial, there were no significant differences in eggshell strength, eggshell thickness and eggshell color among the treatments, except for eggshell strength at 4 and 8 wk and eggshell thickness at 0 wk. In addition, no differences in egg yolk color and egg yolk index were found for all treatments throughout the 8-wk feeding period, except for egg yolk color at 0 wk. Thus, using various types of fermented red ginseng marc with red koji to laying hens did not improve eggshell and egg yolk quality characteristics.

• 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.

• Food Science of Animal Resources
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• v.32 no.5
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• pp.561-570
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• 2012

The objective of this study was to evaluate the effects of an atmospheric pressure plasma (APP) jet on L. monocytogenes inactivation, quality characteristics, and genotoxicological safety of cooked egg white and yolk. APP treatment using He gas resulted in a 5 decimal reduction in the number of L. monocytogenes in cooked egg white, whereas that using $He+O_2$, $N_2$, and $N_2+O_2$ decreased the number further, and to undetectable levels. All treatments of cooked egg yolk resulted in undetectable levels of inoculated L. monocytogenes. There were no viable cells of total aerobic bacteria after APP treatment on day 0 while the control showed approximately 3-4 Log CFU/g. On day 7, the numbers of total aerobic bacteria had increased by approximately 3 log cycles in cooked egg white, but there were no viable cells in cooked egg yolk after 2 min of APP jet. APP treatment decreased the $L^*$-values of cooked egg white and yolk significantly on day 0. No significant sensory differences were found among the cooked egg white samples, whereas significant reductions in flavor, taste, and overall acceptability were found in cooked egg yolks treated with APP jets. SOS chromotest did not reveal the presence of genotoxic products following APP treatments of cooked egg white and yolk. Therefore, it can be concluded that APP jets can be used as a non-thermal means to enhance the safety and extend the shelf-life of cooked egg white and yolk.

• Journal of Mushroom
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• v.20 no.4
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• pp.254-257
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• 2022

Owing to its excellent nutritional value, eggs are among the most important components of the human diet. Gender and environmental factors, such as feed composition, may alter the nutritional profile and quality of eggs. Feed additives have recently been used to enhance the health and productivity of hens, which has resulted in the production of higher-quality eggs. The fungus Cordyceps militaris, a well-established source of traditional medicines, contains potential bioactive metabolites, which prompted us to examine the effects of C. militaris-supplemented diets on the quality of hens' eggs. The hens of two species (Gallus gallus domesticus and Araucana) were fed with one of three different diets: a control diet and diets supplemented with 2% or 5% of C. militaris. Egg quality was determined by measuring the Haugh Unit, yolk color, and shell thickness. In addition, egg and shell densities together with the ratio of yolk to albumen were calculated. Eggshell thickness and yolk color were both enhanced by the addition of C. militaris, whereas Haugh Unit values were somewhat reduced. Egg size, eggshell weight, and yolk and albumen production were all enhanced by C. militaris supplementation. Notably, in hens fed the 2% C. militaris-supplemented diet, enhancement was more evident in the yolk than in the albumen. The overall quality of the egg yolk was enhanced when 2% C. militaris was added to the hens' diet, which led to increases in both yolk color and quantity. Eggshell thickness and weight were also higher among eggs laid by hens fed the supplemented diets. Although these effects differed depending on the chicken species, we established that, in general, C. militaris contributes to improving egg quality.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2000.04a
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• pp.23-36
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• 2000

Hurdle technique was used to remove cholesterol efficiently from liquid egg yolk. The quality of the low cholesterol egg products from the process were evaluated. From the 75 % cholesterol reduced egg yolk through $\beta$-cyclodextrin treatment. 2 times weight of soy bean oil was added to the egg yolk and homogenized followed by centrifuged to be maximized to remove cholesterol. When the pH of the yolk was adjusted to 9, 92 % of cholesterol was removed while 95.4 % of cholesterol was removed when 3 times weight of soy bean oil was added to the egg yolk. As the results of application of supercritical carbon dioxide extraction to the 75 % cholesterol reduced egg yolk through ${\beta}$-cyclodextrin treatment, 92.5 % of the cholesterol was removed from the egg yolk at $35^{\circ}C$, 4,500 psi, for 4 hours under co-solvent. The quality characteristics of the produced low cholesterol egg products were analysed. The cholesterol reduced egg yolk produced from ${\beta}$-cyclodextrin and soy bean oil treatment showed the lower emulsion capacity compared with control. The fatty acid composition of the cholesterol reduced egg yolk produced from ${\bet}a$-cyclodextrin and soy bean oil treatment showed increased C18:2 and C18:3 compared with control while decreased C16:1 and C18: 1 compared with control. The saponification method with extracting solvent of hexane showed that cholesterol concentration was 28.1 %. The quantity of hydrolysis solution(95 % ethanol : 33 % KOH = 94 : 6) was varied from 40 to 80 times of sample weights and the cholesterol concentration of 35.7 % was the highest result in the 60 times(v/w) hydrolysis solution. Cholesterol concentration of 35.7 % was recovered at the first trial with saponification method. but it could be improved up to 95.7 % after 4 times repetitive purification.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.11
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• pp.1503-1509
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• 2010

Forty-eight 40-wk-old Hi-sex laying hens were individually caged in an environmentally controlled house to evaluate the effect of garlic (Allium Sativum) juice administration on egg production, egg quality, and yolk cholesterol. Garlic juice was prepared by blending pealed garlic cloves with distilled water (1:1, w/w). Hens were randomly divided into four equal groups; one served as a control and the other three groups were individually gavaged, 3.75 ml, 7.5 ml, or 15 ml garlic juice, three times a week, which respectively represented 0.25, 0.50 and 1% of body weight. Egg production was recorded on a daily basis; egg weight, albumen height, albumen and yolk pH, Haugh unit, and bacterial count of E. coli-challenged eggs were recorded at day of oviposition (day-1) and after 5 and 10 days of storage at room temperature. Yolk cholesterol content was analyzed for five successive weeks. Garlic juice increased (p<0.05) egg weight and mass with no change in egg production intensity. Garlic juice administration recorded higher (p<0.05) albumen height and improvement in Haugh unit. Also, eggs from garlic-treated hens recorded lower (p<0.05) albumen and yolk pH when compared to eggs collected from control hens. Garlic reduced (p<0.05) the $log_{10}$ of bacterial count in egg contents linearly when challenged with E. coli. Egg-yolk cholesterol content was not influenced by garlic juice administration. It is concluded that garlic juice improved performance characteristics and may increase egg shelf life as indicated by egg quality improvement and lower bacterial count of E. coli-challenged eggs. The levels of garlic juice used in this study were insufficient to influence egg yolk cholesterol.

• Food Quality and Culture
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• v.1 no.1
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• pp.6-12
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• 2007

In this study, we examined the effects of egg yolk powder added to flour dough on the lipid oxidation of fried products during storage. The flour dough containing the egg yolk powder (0, 5, and 10%) was fried in sunflower oil at $180^{\circ}C$ for 90 sec. The fried products were then stored at $60^{\circ}C$ for 9 days in the dark. The lipid oxidation of the fried products was evaluated by fatty acid composition, peroxide values (POV), conjugated dienoic acid (CDA) contents, and thiobarbituric acid (TBA) values. The color and phospholipids (PL) contents of the fried products were also determined by colorimetry and high performance liquid chromatography, respectively. The addition of egg yolk powder to the dough decreased the POV, CDA contents, and TBA values of the fried products during storage. Although POV, CDA contents, and TBA values significantly increased in the products without egg yolk powder during storage, little change was observed in the products with egg yolk powder. The PL contents remained relatively constant in the flied products added with egg yolk powder during storage. The lightness and greenness of the fried products decreased, and the yellowness increased, as the storage time increased. The results clearly indicate that the addition of egg yolk powder to the dough improved the lipid oxidative stability of the fried products during storage in the dark, and the PL in the egg yolk might have contributed to the improvements in lipid oxidative stability.

• Journal of the East Asian Society of Dietary Life
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• v.20 no.1
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• pp.77-83
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• 2010

The study was conducted to investigate the effect of particle size on the physicochemical properties of egg yolk-rice porridge. The pH of egg yolk-rice porridge was decreased when compared to that of the control, while the lightness and yellowness was increased as the rice particle size increased. The viscosity of whole particle egg yolk porridge was highest among the three porridges at $40^{\circ}C$. The protein content of the egg yolk-rice porridge was increased three-fold, when compared to that of the rice porridges. The total amino acid content of egg yolk-rice porridge was 1,500.6 mg/100 g, while that of rice was 1,147.5 mg/100 g. The Lys and Thr content of the amino acid content of egg yolk-rice porridge were also increased. Sensory evaluation results revealed that the half particle size rice egg yolk-rice porridge had the highest scores in color, taste and over-all preference. Based on these results, the half particle size egg yolk-porridge had good quality with respect to both the physicochemical and nutritional properties.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.10
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• pp.1447-1455
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• 2011

Sixty four, 30-week-old, Lohmann Brown-Lite laying hens were randomly allocated to one of four treatments with eight replicates per treatment and two hens per replicate for a 10 week study. The control diet was a high energy (11.81 MJ/kg) diet and the moderate energy (11.39 MJ/kg) diets were formulated dropping the level of animal fat. The three moderate energy diets were fed either unsupplemented (0.0%) or supplemented with 0.05 or 0.10% glycine. There were no significant differences (p>0.05) in hen-day egg production, egg weight, feed intake or feed conversion between birds fed the unsupplemented moderate energy and high energy diets. Significant differences were detected concerning egg components and quality measurements as assessed by albumen percentage (p = 0.02), yolk weight (p = 0.02), yolk percentage (p<0.01), yolk to albumen ratio (p<0.01) and yolk color (p = 0.01) between birds fed the unsupplemented moderate and high energy diets. Glycine supplementation of the moderate energy diet linearly increased (p<0.01) egg weight and feed intake with no significant (p>0.05) effects on egg production or feed conversion. Glycine supplementation significantly increased egg content (p<0.01), albumen weight (p<0.01) and percentage (p<0.01) as well as yolk weight (p<0.01) while yolk percentage (p = 0.04), yolk to albumen ratio (p = 0.01) and egg shell percentage (p<0.01) were linearly decreased. Supplementation with glycine produced a tendency (p = 0.09) towards an increase in the percentage of large eggs (63-72.9 g) produced with a concomitant decrease in the percentage of small (below 53 g) eggs (p = 0.09). The overall results of this study indicate that glycine supplementation of laying hen rations has the potential to increase egg production and weight. These increases appeared to be mediated through increases in feed intake and the ileal digestibility of fat and energy.