• Korean journal of food and cookery science
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• v.15 no.6
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• pp.645-651
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• 1999

The lipid and fatty acid composition of various poultry eggs were examined after extracting yolk oils from the eggs of caged hen, open barn-reared hen, mallard, and muscovy duck. Total lipid content in 100 g of each edible portion was the highest in muscovy duck egg followed by open barn-reared hen, mallard, caged hen, and natural hen eggs. The triglyceride contents in the egg were in the order of caged hen, open barn-reared hen, natural hen, mallard, and muscovy duck. The cholesterol contents in total lipid were the highest in caged hen and muscovy duck eggs(4.5%), and the lowest in mallard(3.3%). Caged hen eggs had higher neutral lipid ratio among total lipid, but had lower ratio of glycolipid and phospholipid compared with those of the open barn-reared hens. For fatty acid composition, linoleic acid was the highest in the muscovy and linolenic acid was the highest in open barn-reared hen eggs. The contents of arachidonic acid and Eicosapentaenoic acid(EPA) were the highest in muscovy eggs. On the other hand, the content of Docosahexaenoic acid(DHA) was the highest in muscovy duck eggs.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.9
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• pp.1328-1332
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• 2011

This study was carried out to investigate changes in epigallocatechin gallate (EGCG) contents and antioxidant activity of duck egg after pressurized soaking in green tea extract. The duck eggs were soaked in different concentrations of green tea extract (10~30%) and subjected to pressures of 0.1~5.0 MPa for 30 min at ambient temperature in a lab model high-pressure rig. After pressured treatment at 5.0 MPa in 30% green tea extract, EGCG content of duck egg white (20 mg/100 g) markedly increased compared to that of untreated sample (0.17 mg/100 g). Moreover, the antioxidant, hepato-protective, and cellular antioxidant activities of duck egg white after pressured treatment at 5 MPa in 30% green tea extract were all higher than those of untreated sample. Our results could have a direct impact on duck egg consumption by increasing consumer awareness of the health benefits of duck eggs.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.8
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• pp.1069-1074
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• 2014

In China and South East Asia, the duck (common duck) is important in egg production for human consumption. Plumage color is a breed characteristic and of economic importance, together with egg production. Our aim in this study was to investigate the inheritance of plumage color in three Chinese indigenous egg-type duck breeds, Shan Ma (S), Putian White (F) and Putian black (P), and some of their crossbreds. These three breeds have different plumage color and are used in crossbreeding. The crossbred laying ducks $F{\times}(P{\times}S)$ and $F{\times}(S{\times}P)$ showed highly improved laying ability but heterogeneous plumage color. Genotypes at four relevant loci were investigated by studying down color and pattern in ducklings after crossbreeding. $F_1$ ducklings from the matings $F{\times}S$ and $S{\times}F$, $P{\times}S$, and $S{\times}P$ were classified into four classes of plumage color (the Shan Ma plumage color, black, white, or multicolored) over three generations. Parents were selected for the Shan Ma plumage color of their progeny. In the fourth generation, P male and P female ducks were selected according to the frequency of the desired class of plumage color (Shan Ma) of their $F_1$ progeny to obtain the so-called "Brown Putian Ma duck". The Shan Ma duck genotype was identified as having the restricted mallard color pattern ($M^RM^R$), full expression of any of the patterns or colors (CC), no extended black (ee) and no brown dilution D (D). The Putian White genotype was recessive white (cc), no extended black (ee) and no brown dilution D (D). The Putian Black genotype exhibited full expression of extended black (E gene) and no brown dilution (CCEE D [D]). It was shown that $F{\times}S$ and $S{\times}F$ tests should be implemented to eliminate the recessive white c allele in the S line and the dominant extended black E allele in the F line. It was also shown that the Brown Putian Ma obtained from Putian Black, with no extended black genotype (ee), could be used to get rid of the black plumage (E gene) in the crossbred ducks. This could provide a solution for producing 3-way crossbred ducks Putian $White{\times}$(Putian-$Ma{\times}Shan$ Ma) and Putian $White{\times}$(Shan $Ma{\times}Putian$-Ma), with the desired Shan Ma feather color.

• Food Science of Animal Resources
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• v.42 no.4
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• pp.689-711
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• 2022

The purpose of our study was to determine the impact of rosemary extract in duck eggs, as determined by in vitro antioxidant capacity, lipid oxidation, fatty acid profiles, and flavor analyses. Three groups of salted duck eggs were compared: A control group and group enriched with 0.1% and 0.5% (w/v) rosemary extracts for 28 days of salting. In a time-dependent manner, the radical scavenging activity and reduction power of eggs with 0.5% (w/v) rosemary extract were significantly higher those of the control at 28 days after salting. The fatty acid profiles of salted egg were significantly affected by rosemary extract and salting time. Palmitic acid was the most abundant fatty acid in salted egg treated with rosemary extract, followed by linoleic acid and arachidonic acid. Furthermore, the treated eggs contained more docosahexaenoic acid than the control ones. And the treated eggs also have a considerable impact on the lipid oxidation process (primary and secondary oxidation). As a result, rosemary extract can be used as a natural antioxidant spice to prevent oxidation and extend the shelf life of eggs during storage. Furthermore, flavor research using solid phase microextraction - gas chromatography - mass spectrometry and an electronic nose demonstrated that adding rosemary extract to salted eggs could give them a distinct flavor.

• The Korean Journal of Food And Nutrition
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• v.19 no.1
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• pp.62-69
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• 2006

This study was performed to investigate the biocogical activity of the phospholipid separated and purified from duck egg yolk as functional brain food. A quantitative restriction of maternal diet was given to Sprague-Dawely rats during lactation. Animals were separated into three groups, such as control, duck egg phospholipid(PL) or pig-brain phospholipid additions groups. And ad libitum during lactation was given to control groups. All of the offsprings at 3 weeks of age fed a diet ad libitum for 4 weeks of rehabilitation. Body weight and brain weight and protein, phosphplipid, and cholesterol were determined on offsprings of each of group sacrificed at 0, 1, 2, 3, 5 and 7 weeks of age, sacrified body weight of duck egg phospholipid and pig brain phospholipid group were significantly higher than the control group. Body weight and brain weight after a recovery period were significantly at the control group. However, protein, phospholipid and cholesterol contents were significantly high than the control group. Response latency in the passive avoidance task was the lowest in the ${\beta}$-amyloid group and highest in the phospholipid group. It is consequently suggested that phospholipid supplement may be effective in memory improvement.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.11
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• pp.1587-1593
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• 2009

Duck egg white (DEW) hydrolysates were prepared by five enzymes (papain, trypsin, chymotrypsin, alcalase, and flavourzyme) and their antioxidant activities investigated in this study. DEW hydrolyzed with papain (DEWHP) had the highest peptide content among the five enzymatic treatments. Besides, the peptide content of DEWHP increased when the enzyme to substrate ratio (E/S ratio) increased. It was suggested that higher E/S ratio contributed to elevate the degree of hydrolysis of DEW effectively. Similar results were also obtained by Tricine-SDS-PAGE. In addition, SDS-PAGE patterns indicated papain was the only one amongst all enzymes with the ability to hydrolyze DEW. In antioxidant properties, DEWHP showed more than 70% of inhibitory activity on linoleic acid peroxidation and superoxide anion scavenging. Moreover, the $Fe^{2+}$ chelating effect of DEWHP was greater than 90%, while no significant difference was observed in DPPH radical scavenging and reducing ability. The results of peptide contents, antioxidant activities and electrophoresis suggested that the higher the peptide content, the stronger the antioxidant activities in DEWHP.

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.2
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• pp.67-75
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• 1989

Studies were conducted to compare the utilization of dietary calcium between brown laying Tsaiya duck and Leghorn hen. Birds were fed corn-soybean diets containing 1.0, 2.0, 3.0, 4.0 and 5.0% calcium, respectively, with five birds per treatment. The metabolizability of calcium was determined by the indicator method. Experiments were conducted three times each at the age of 27, 31 and 36 weeks. Results appeared that duck eggs were heavier with better shell quality in comparison with hen eggs. Ducks fed 1% calcium diet resulted in severely depressed egg production (19%), but not for hens which still had 56% egg production. The metabolizability of calcium for hens was significantly higher than that for ducks (P<0.05) when both were fed diets containing 1 or 2% calcium. As the dietary calcium level was increased to 3 to 5%, there was no significant difference in calcium metabolizability between ducks and hens. When the dietary calcium was between 2 to 5%, the ducks retained more calcium than did the hens. Plasma calcium content for both hens and ducks fed 1% calcium diet was about the same. When the amount of the dietary calcium was increased to 2-5%, the plasma calcium level of ducks was approximately 7-10 mg/dl higher than that of hens. The calcium content in the egg shell of duck was significantly higher than that of hens, too. As the dietary calcium level was increased, there was a decreased magnesium content in the eggshell of hens, but not for ducks. The magnesium level in the eggshell was higher in hens than that in ducks. It is concluded that ducks could retain significantly more calcium and maintain higher plasma calcium level which might be the reason for larger eggs with better shell quality by ducks.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.1
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• pp.173-181
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• 1992

Duck is an important domestic animal, especially in Asia. Eighty five percent of ducks in the world are kept in Asia, especially in the East and South Asia regions. The ancestor of domesticated ducks was mallard (Anas platylhynchos), which are still migrating between north and southern parts in Eurasia. Ducks have been domesticated in China for at least 3000 years ago. Phylogenetic studies on ducks, employing electrophoresis of blood proteins, indicate a marked difference of genetic constitution between duck breeds in southeast Asia and those in northeast Asia. Duck embryonic ovary is much more active in secretion of sex steroid hormones especially estradiol than the embryonic testes. Estradiol secreted by the embryonic left ovary has an important role in female sexual differentiation in ducks. In the female ducks, plasma LH, estradiol and testosterone levels increase and reach peaks shortly before the first egg, while progesterone level reach a peak shortly after the first egg. In laying ducks oviposition mostly occurs in the last 3 hr of darkness and first hr of light ranging 02:00-06:00 under 14 hr light (05:00-19:00) and 10 hr darkness photoperiodic condition. Measurements of plasma hormone levels reveal that onset of darkness is a major signal for LH release from the pituitary and the subsequent release of progesterone from ovary, and for induction of ovulation in the female duck.

• Journal of the Korean GEO-environmental Society
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• v.3 no.2
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• pp.5-14
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• 2002

In this study, stress-deformation characteristics of buried pipe are studied. A numerical model, i.e., Egg-Cam Clay is introduced for the analysis of soft clay. Cam Clay model has a difficulty in analyzing soft clay that has two properties of shrinkage and swelling. Egg-Cam Clay model is modified format of Cam Clay model. In addition, Mohr-Coulomb model using finite element method is employed to verify effects of the geogrid, EPS geofoam. Stress deformation of several cases of pipe and other reinforcemnt material combinations are analyzed. Geofoam and geogrid have positive effects on the deformation characteristics.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.9
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• pp.1487-1496
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• 2020

Objective: The objective of this study was to look for optimal preparation of hydrolysates of desalted duck egg white powder (DDEWP) by the three different proteases and to investigate their antioxidant and antimicrobial properties. Methods: DDEWP was hydrolyzed by three proteases, including pepsin (PEP), Bacillus spp. (BA) and natokinase (NAT) with three different enzyme concentrations (0.1%, 0.3%, and 0.5%), individually. The important key hydrolysis parameters such as hydrolysis degree, yield, antioxidant and antimicrobial activity were evaluated in this experiment. Results: The results showed that the degree of hydrolysis (DH) of all treatments increased with increasing hydrolysis time and protease concentrations. The antioxidant and antimicrobial activities of the hydrolysates were affected by type and concentration of protease as well as hydrolysis time. Hydrolysis of PEP significantly (p<0.05) obtained the highest yield of hydrolysates, however, both of BA and NAT showed substantially lower DH values and still did not exceed 5% by the end of hydrolysis. Among the different hydrolysates, PEP exhibited significantly higher 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity than BA and NAT. All DDEWP hydrolysates from PEP had low ferrous ion chelating activity (<37%) that was significantly lower than that of NAT (>37% to 92%) and BA (30% to 79%). Besides, DDEWP hydrolysates of PEP presented significantly higher reducing power than BA and NAT. In antimicrobial activities, Escherichia coli, Salmonella typhimurium, and Pseudomonas aeruginosa were not effectively inhibited by any DDEWP hydrolysates of PEP except for Staphylococcus aureus. Especially, the excellent antibacterial activity against S. aureus only was displayed in DDEWP hydrolysates of PEP 0.1%. Conclusion: DDEWP hydrolysates from PEP demonstrated significantly better DH, yield, DPPH radical scavenging activity and reducing power, furthermore, had excellent inhibitory on S. aureus due to large clear zone and moderated inhibitory in bactericidal inhibition.