• Journal of Animal Science and Technology
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• v.52 no.5
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• pp.427-434
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• 2010

This study was conducted to investigate the growth performance and meat quality improvement according to castration, optimal feeding management and ruminally protected amino acid-enriched fatty acid (RPAAFA) for the unselected Hanwoo bulls in the performance test. Bulls were castrated at approximately 14 months of age. Sixteen Hanwoo steers, 15 months of age and weighing $412.9{\pm}24.9kg$, were distributed into 2 groups. Steers were fed a basal diet supplemented with RPAAFA at 0 g (control) or 100 g (treatment), respectively for 12 months. Steers were slaughtered at 27 months of age. Average daily gain for treatment tended to be higher (p=0.10) than that of control, whereas feed conversion ratio tended to be lower (p=0.07) in treatment than in control. The supplementation of RPAAFA did not affect rib eye area, back fat thickness, meat color, fat color, texture and maturity. The appearance rates of yield 'A' grade and high quality grade ($1^{++}$, $1^+$ and 1) were higher in treatment than in control. The content of moisture, fat, protein and ash in longissimus muscles were similar between control and treatment. The supplementation of RPAAFA did not affect water-holding capacity, oxidation and reduction potential, myoglobin and fatty acid contents in longissimus muscles. Thus, present results indicate that castration, optimal feeding management and RPAAFA may be recommended for improving growth performance and quality grade of the unselected Hanwoo bulls in the performance test.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.10 no.1
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• pp.1-7
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• 2005

Tidal flats have been regarded to carry out transformation and removal of land-derived organic matter, and this purifying capability of organic matter by tidal flats is one of very important reasons for their conservation. However, integral biogeochemical studies on production and decomposition of organic matter by benthic microbes in tidal flats have been absent in Korea, although the information is indispensable to quantification of the purifying capability. Our major goals in this multidisciplinary research were to understand major biogeochemical processes and rates mediated by diverse groups of microbes dominating material cycles in the tidal flats, and to assess the contribution of benthic microbes to removal of organic matter and nutrients in the tidal flats. Our study sites were Ganghwa and Incheon north-port tidal flats that had been regarded as naturally well reserved and organically polluted, respectively. Our research group measured over 3 years primary production, biomass and community structure of primary producers, abundance and production of bacteria, enzyme activities, distribution of protozoa and protozoan grazing rates, rates of denitrification and sulfate reduction, early sediment diagenesis, primary production and respiration based on oxygen microelectrode. We analyzed major features of each biogeochemical process and their interactions. The results are compiled in the following articles in this special issue: An (2005), Hwang and Cho (2005), Mok et at. (2005), Na and Lee (2005), Yang et at. (2005), and Yoo and Choi (2005).

• Food Science of Animal Resources
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• v.32 no.4
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• pp.497-503
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• 2012

This study was performed in order to evaluate the antioxidant activities of red beet extracts as well as the physicochemical properties and microbial changes of pork patties containing red beet during refrigerated storage. Red beet was extracted with water and ethanol. Red beet water extracts (RBW) and red beet ethanol extracts (RBE) were diluted with various concentrations (0.05~1.0%). DPPH radical scavenging activity and iron chelation activity of RBW showed a higher level than those of RBE (p<0.05). In particular, the iron chelation activity of RBW was over 53.4% at all levels. In addition, RBW at 1% had nearly 100% activity. On the other hand, the reducing powers of RBE were higher than those of RBW (p<0.05), and the antioxidant activity on linoleic acid emulsion of RBW was over 83% at all levels. Based on these model studies, 0.5% levels of RBW and RBE were added to ground pork patties (GPP), and the physicochemical properties and microbial changes of red beet GPP were evaluated during storage (0~14 d) at $4^{\circ}C$. The pH and microbial counts increased with increased storage time (p<0.05). Pork patties with BHT showed the lowest thiobarbituric acid reactive substances (TBARS) and microbial counts, and those with red beet had lower TBARS than the control (p<0.05). These results indicated that both red beet water and ethanol extracts could be used as natural antioxidants of pork patties during storage.