• Korean Journal of Organic Agriculture
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• v.13 no.1
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• pp.113-122
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• 2005

for 50% of Rash water every week during experimental period. Eight of 100L of aquarium, eight kg of mudfish and four of female korean native chicken were used this study. This study are divided according to the mudfish fed on commercial mudfish diet in the four of control group and fed on raw hens excreta in the four treatment group. The chemical composition was compared with commercial mudfish diet and hens excreta. In the both sample, crude protein contents was almost same. The crude fat and crude ash were higher in hens excreta than commercial mudfish diet. The growth performance of mudfish tend to high when fed hens excreta. There were no differences in contents of E. Coli and Salmonella and pH of water in aquariums between the groups. Mortality of mudfish tend to decrease when fed hens excreta. No problem with mudfish health was observed during the experimental period of 35 days. These results indicated that it is possible to raising mudfish fed on hens excreta only.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.5
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• pp.695-701
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• 2016

This study was conducted to observe antioxidant enzyme activity, iron content and lipid oxidation of Korean native chickens and other poultry. The breast and thigh meat of three Korean native chicken breeds including Woorimatdak, Hyunin black and Yeonsan ogye, and three commercial poultry breeds including the broiler, White Leghorn and Pekin duck (Anasplatyrhyncos domesticus) were studied. The analyses of the antioxidant enzymes activity, iron content and lipid oxidation were performed in raw and cooked samples. The activity of catalase (CAT) in the thigh meat was higher than that of the breast meat of three Korean native chickens and the broiler, respectively. The activity of glutathione peroxidase (GPx) in the uncooked thigh meat of three Korean native chickens was higher than that of the breasts. The breast meat of Woorimatdak and Pekin duck had higher superoxide dismutase (SOD) activity than the others, while only the thigh meat of Pekin duck had the highest activity. Cooking inactivated CAT and decreased the activity of GPx and SOD. The thigh meat of Woorimatdak, White Leghorn, Yeonsan ogye and Hyunin black contained more total iron than the breast meat of those breeds. The heme-iron lost during cooking ranged from 3.2% to 14.8%. It is noted that the thigh meat had higher thiobarbituric acid reactive substances values than the breast in all chicken breeds. Though Woorimatdak showed higher antioxidant enzyme activity and lower released-iron percentage among Korean native chickens, no differences were found on lipid oxidation. We confirm that the dark meat of poultry exhibited higher antioxidant enzyme activity and contained more iron than the white meat.

• Journal of Food Hygiene and Safety
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• v.29 no.3
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• pp.228-233
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• 2014

This study was performed to examine antimicrobial resistance of Enterococcus spp. strains from retail raw meat and fish products purchased in 2012. 43 Enterococcus spp. strains were isolated from a total of 207 samples (beef, pork, chicken, fish) with contamination rate of 20.8%. The isolated strains were identified as E. faecalis (22 strains), E. gallinarum, E. hirae (5 strains), E. avium (4 strains), E. faecium (3 strains), E. duram, E. casseliflavus (2 strains). Susceptibility to 10 antibiotics was tested, and the highest resistance was observed to tetracycline. And antimicrobial resistance rates were presented below 20% with most of the other antimicrobial agents. The isolated Enterococci from chicken showed higher resistance also to ciprofloxacin and erythromycin, not only to tetracycline, compared to the isolated Enterococci from beef, pork and fish. Sixteen isolates (37.2%) were sensitive to all antibiotics. Four isolates (9.3%) were resistant to 3 or more antibiotics. Vancomycin-resistant enterococci (VRE) was not identified. According to the results of genetic similarity pattern analysis via PFGE and rep-PCR, Enterococci strains showed different patterns from these collected in 2011. This indicates that there is no genetic similarity among all the strains.

• Journal of Microbiology and Biotechnology
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• v.27 no.11
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• pp.1942-1951
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• 2017

Campylobacter jejuni and Campylobacter coli are important foodborne pathogenic bacteria, particularly in poultry meat. In this study, the presence of extracellular DNase activity was investigated for biofilm-deficient Campylobacter strains versus biofilm-forming Campylobacter strains isolated from chickens, to understand the relationship between extracellular DNase activity and biofilm formation. A biofilm-forming reference strain, C. jejuni NCTC11168, was co-incubated with biofilm non-forming strains isolated from raw chickens or their supernatants. The biofilm non-forming strains or supernatants significantly prohibited the biofilm formation of C. jejuni NCTC11168. In addition, the strains degraded pre-formed biofilms of C. jejuni NCTC11168. Degradation of C. jejuni NCTC11168 biofilm was confirmed after treatment with the supernatant of the biofilm non-forming strain 2-1 by confocal laser scanning microscopy. Quantitative analysis of the biofilm matrix revealed reduction of extracellular DNA (16%) and proteins (8.7%) after treatment. Whereas the biofilm-forming strains C. jejuni Y23-5 and C. coli 34-3 isolated from raw chickens and the C. jejuni NCTC11168 reference strain showed no extracellular DNase activity against their own genomic DNA, most biofilm non-forming strains tested, including C. jejuni 2-1, C. coli 34-1, and C. jejuni 63-1, exhibited obvious extracellular DNase activities against their own or 11168 genomic DNA, except for one biofilm non-former, C. jejuni 22-1. Our results suggest that extracellular DNase activity is a common feature suppressing biofilm formation among biofilm non-forming C. jejuni or C. coli strains of chicken origin.

• Food Science of Animal Resources
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• v.38 no.3
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• pp.433-441
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• 2018

The objective of present study was to investigate the effect of cooking and their combinations with re-heating methods on the formation of cholesterol oxidation products (COPs) in stored chicken thigh meat. Pan roasting, steaming, oven grilling, charcoal grilling, and microwaving were used for cooking. Re-heating of samples was done using the same cooking methods or microwaving after 3 and 6 d of refrigerated storage. Cooking and re-heating resulted in reduction of crude fat and cholesterol contents of chicken thigh meat depending on storage period before re-heating. Cooking and storage period had no influence on the total amount of COPs. The highest total amount of COPs was observed in meat samples cooked by steaming and reheated by microwaving after 6 d of storage, which showed similar value to raw chicken meat stored for 6 days. However, different re-heating methods formed different types of COPs depending on storage period before re-heating. The high amount (p<0.05) of 25-hydroxycholesterol or ${\alpha}-epoxide$ was detected in meat samples reheated by steaming or microwaving at 3 or 6 d of storage after steamed cooking, respectively. As a result, the combination of steaming and re-heating with microwaving could increase the total amount of COPs in chicken thigh meat and different cooking/re-heating methods could form different types of COPs, even though no significant difference in the total amount of COPs depending on storage period.

• Journal of Microbiology and Biotechnology
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• v.18 no.11
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• pp.1853-1857
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• 2008

Salmonella contamination in chicken meat was studied with 100 chicken meat samples purchased from 55 shops located in various regions. A total of 21 isolates of Salmonella enterica were isolated from 21 chicken meat samples from four shops located at open markets, whereas there were none from supermarkets with well-equipped cold systems. Among these, 18 isolates were identified as Salmonella enterica serotype Haardt (S. Haardt) and three isolates were S. enterica serotype Muenchen. When the minimal inhibitory concentrations of the S. Haardt isolates were assayed with the agar dilution method to determine susceptibility to ampicillin, chloramphenicol, sulfisoxazole, tetracycline, and nalidixic acid, all 18 isolates were resistant to tetracycline and nalidixic acid and nine of these were resistant to ampicillin. These isolates showed reduced susceptibility to eight fluoroquinolones including ciprofloxacin, enrofloxacin, levofloxacin, gatifloxacin, gemifloxacin, moxifloxacin, norfloxacin, and ofloxacin. When quinolone resistance determining regions of gyrA and gyrB were sequenced, every isolate had the same missense mutation Ser83$\rightarrow$Tyr (TCC$\rightarrow$+TAC) in gyrA, whereas no mutation was found in gyrB. Pulsed-field gel electrophoresis with XbaI revealed a close relationship among these isolates, suggesting a contamination of raw chicken meat with clonal spread of nalidixic acid-resistant and quinolone-reduced susceptibility S. Haardt in chickens. Results in this study show the importance of a well-equipped cold system and the prudent use of fluoroquinolone in chickens to prevent the occurrence of quinolone-resistant isolates.

• Food Science of Animal Resources
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• v.43 no.2
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• pp.305-318
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• 2023

This study investigated the protein digestibility of chicken breast and thigh in an in vitro digestion model to determine the better protein sources for the elderly in terms of bioavailability. For this purpose, the biochemical traits of raw muscles and the structural properties of myofibrillar proteins were monitored. The thigh had higher pH, 10% trichloroacetic acid-soluble α-amino groups, and protein carbonyl content than the breast (p<0.05). In the proximate composition, the thigh had higher crude fat and lower crude protein content than the breast (p<0.05). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of myofibrillar proteins showed noticeable differences in the band intensities of tropomyosin α-chain and myosin light chain-3 between the thigh and breast. The intrinsic tryptophan fluorescence intensity of myosin was lower in the thigh than in the breast (p<0.05). Moreover, circular dichroism spectroscopy of myosin revealed that the thigh had higher α-helical and lower β-sheet structures than the breast (p<0.05). The cooked muscles were then chopped and digested in the elderly digestion model. The thigh had more α-amino groups than the breast after both gastric and gastrointestinal digestion (p<0.05). SDS-PAGE analysis of the gastric digesta showed that more bands remained in the digesta of the breast than that of the thigh. The content of proteins less than 3 kDa in the gastrointestinal digesta was also higher in the thigh than in the breast (p<0.05). These results reveal that chicken thigh with higher in vitro protein digestibility is a more appropriate protein source for the elderly than chicken breast.

• Food Science of Animal Resources
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• v.38 no.5
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• pp.936-949
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• 2018

Changes in microbial community and physicochemical traits of chicken summer sausage made from spent layer thigh added with different level (0%, 0.1%, 0.3%, and 0.5% w/w) of ground chopi (Zanthoxylum piperitum) during manufacture were analyzed. The microbial community was profiled and analyzed by sequencing 16S rRNA gene using Illumina MiSeq. Samples were taken from raw sausage batter, after 15 h of fermentation, 8 h of cooking including cooling down, and 7 d of drying. The final pH of the sausage was reduced by the addition of ground chopi. However, no clear effect on water activity was observed. Ground chopi inhibited the development of red curing color after fermentation as it exhibited antimicrobial effect. However, the effect on species richness and microbial composition after cooking was unclear. Ground chopi delayed lipid oxidation during manufacture and the effect was dependent on the addition level. Fermentation reduced the species richness with a dominancy of lactic acid bacteria. The profile of microbiota in the raw batter was different from other stages, while the closest relationship was observed after cooking and drying. Proteobacteria was predominant, followed by Firmicutes and Bacteroidetes in raw samples. Firmicutes became dominating after fermentation and so forth, whereas other predominant phylum decreased. At genus level, unclassified Lactobacillales was the most abundant group found after fermentation and so forth. Therefore, the overall microbial composition aspects were mainly controlled during fermentation by the abundance of lactic acid bacteria, while bacterial counts and lipid oxidation were controlled by cooking and the addition of ground chopi.

• Korean Journal of Veterinary Research
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• v.39 no.3
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• pp.513-522
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• 1999

DNA hybridization assay using probes prepared from liver was carried out to identify species characterization of the domestic animals. Gel electrophoresis showed that the target DNA extracted from raw muscle were 1kb and uniform pattern while fragments size of heated muscle were irregular. Hybridization was performed by adding 200ng/ml probe in hybridization solution and incubating for 12 hours at $68^{\circ}C$. To obtain good discrimination, applied washing buffer and washing step differently depending on the species. The probes of pig, horse and dog formed the specific hybrids with each target DNA respectively. Although cross reaction was detected in cattle, goat and sheep but signal intensity among these species made the discrimination possible each other. Such pattern was the same in the cases of chicken, turkey and duck. The hybridization pattern of heated muscle was similar to that of raw muscle in general, but the signal intensity was inferior to that of raw muscle. Species identification between closely related animal species, hybridized using the target DNA of such closely related animal species as a blocking agent, remarkable increase of discrimination from the evident decrease of non specific reaction compared with the control group. In addition, in the admixture where certain meat was included in the beef, pork, chicken meat, we could find whether any unjust meat was admixed or not. In this case, detection limit of certain meat in admixture was 1%.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2003.07b
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• pp.67-88
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• 2003

The consumption of poultry meat (chicken and turkey) grew the most during the past few decades due to several contributing factors such as low price. product research and development. favorable meat characteristics, responsive to consumer needs, vertical integration and industry consolidation, new processing equipments and technology, and aggressive marketing. The major processing technologies developed and used in chicken processing include forming/restructuring, tumbling, curing, smoking, massaging, injection, marination, emulsifying, breading, battering, shredding, dicing, and individual quick freezing. These processing technologies were applied to various parts of chicken including whole carcass. Product developments using breast, thigh, and mechanically separated chicken meat greatly increased the utilization of poultry meat. Chicken breast became the symbol of healthy food, which made chicken meat as the most frequent menu items in restaurants. However, the use of and product development for dark meat, which includes thigh, drum, and chicken wings were rather limited due to comparatively high fat content in dark meat. Majority of chicken are currently sold as further processed ready-to-cook or ready-to-eat forms. Major quality issues in chicken meat include pink color problems in uncured cooked breast, lipid oxidation and off-flavor, tenderness PSE breast, and food safety. Research and development to ensure the safety and quality of raw and cooked chicken meat using new processing technologies will be the major issues in the future as they are now. Especially, the application of irradiation in raw and cooked chicken meat products will be increased dramatically within next 5 years. The market share of ready-to-eat cooked meat products will be increased. More portion controlled finished products, dark meat products, and organic and ethnic products with various packaging approaches will also be introduced.