• Journal of the Korean Chemical Society
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• v.21 no.1
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• pp.60-66
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• 1977

In the addition condensation reaction of m-phenylenediamine(MPD) and resorcinol (RES) with formaldehyde, the suspension polymerization in liquid paraffin was performed and the bead polymers were obtained with good results. The polymers were treated with dilute aqueous sodium hydroxide solutions in order to improve the adsorption capacity to the metallic ions and the adsorptivity to the several metallic ions, such as $Cd^{2+},\;Pb^{2+},\;Al^{3+},\;Mg^{2+},\;Co^{2+},\;and\;Hg^{2+}$ of the alkali-treated and untreated polymers were tested. These MPD-RES-F type resins showed better adsorption capacity to the heavy metallic ions such as $Cd^{2+}\;and\;Hg^{2+}$ than the light metallic ions such as $Pb^{2+},\;Al^{3+}\;and\;Mg^{2+}$, and the treatment of the resins with about 20 percent aqueous sodium hydroxide solution showed significant improvement of the adsorption capacity to the metallic ions in all cases.

• Animal Bioscience
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• v.34 no.7
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• pp.1193-1201
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• 2021

Objective: According to market demand, meat duck breeding mainly includes 2 breeding directions: lean Pekin duck (LPD) and fat Pekin duck (FPD). The aim of the present study was to compare carcass and meat quality traits between 2 strains, and to provide basic data for guidelines of processing and meat quality improvement. Methods: A total of 62 female Pekin ducks (32 LPDs and 30 FPDs) were slaughtered at the age of 42 days. The live body weight and carcass traits were measured and calculated. Physical properties of breast muscle were determined by texture analyzer and muscle fibers were measured by paraffin sections. The content of inosine monophosphate (IMP), intramuscular fat (IMF) and fatty acids composition were measured by high-performance liquid chromatography, Soxhlet extraction method and automated gas chromatography respectively. Results: The results showed that the bodyweight of LPDs was higher than that of FPDs. FPDs were significantly higher than LPDs in subcutaneous fat thickness, subcutaneous fat weight, subcutaneous fat percentage, abdominal fat percentage and abdominal fat shear force (p<0.01). LPDs were significantly higher than FPDs in breast muscle thickness, breast muscle weight, breast muscle rate and breast muscle shear force (p<0.01). The muscle fiber average area and fiber diameter of LPDs were significantly higher than those of FPDs (p<0.01). The muscle fiber density of LPDs was significantly lower than that of FPDs (p<0.01). The IMF of LPDs in the breast muscle was significantly higher than that in the FPDs (p<0.01). There was no significant difference between the 2 strains in IMP content (p>0.05). The polyunsaturated fatty acid content of LPDs was significantly higher than that of FPDs (p<0.01), and FPDs had higher saturated fatty acid and monounsaturated fatty acid levels (p<0.05). Conclusion: Long-term breeding work resulted in vast differences between the two strains Pekin ducks. This study provides a reference for differences between LPD and FPD that manifest as a result of long-term selection.