• Journal of Life Science
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• v.23 no.7
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• pp.893-903
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• 2013

The purpose of this study was to evaluate the effects of dietary Flammulina velutipes mycelium (FVM) on physico-chemical properties and nutritional components of chicken meat. Ninety-six broiler chicks (HanHyup No. 3, Korea) were divided into four groups: control (basal diet), T1 (supplemented with 1% FVM), T2 (3%), and T3 (5%). Broiler chicks in each group were slaughtered at 7 weeks of age, and their breast and thigh meat were collected. Lightness ($L^*$) and yellowness ($b^*$) in the T2 and T3 groups were higher than in the control group (p<0.05). The loss of breast meat during cooking was increased in the T1, T2, and T3 groups, and the water-holding capacity of the breast meat was also decreased in these three groups (p<0.05). The water-soluble protein solubility was lower in the T1, T2, and T3 groups than in the control group (p<0.05), but the salt-soluble protein solubility in these three groups was higher than that in the control group (p<0.05). The crude fat content of the breast meat was decreased and that of the thigh meat was increased as the level of FVM was increased (p<0.05). The unsaturated fatty acid content of the breast meat was higher in the T2 and T3 groups than in the control group (p<0.05). The free amino acid content was high in the T1, T2, and T3 groups compared to the control. In conclusion, these results showed that feeding with 3% and 5% FVM increased the L and b values in thigh meat, improved the salt-soluble protein solubility, and increased the content of unsaturated fatty acids and free amino acids.

• Journal of Microbiology and Biotechnology
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• v.26 no.9
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• pp.1551-1556
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• 2016

Broiler meat production worldwide has been plagued by lethal food-poisoning bacteria diseases, including listeriosis. A fatality rate of 15.6% was recorded in human beings in the EU in 2015. During 2013, a total of 200 poultry farm samples, including litter, chicken breast, farm feed, and drinking water, were collected to generate baseline data for the characterization of the genus Listeria in broiler poultry farms. Listeria spp. were detected in a total of 95 (47.5%) poultry farm samples. The isolates of Listeria spp. included L. innocua (28.5%), L. ivanovii (12.5%), L. welshimeri (4.5%), and L. monocytogenes and L. seeligeri (1% each). Listeria spp. contamination rates were higher in farm feed (70%), followed by litter (52.5%), chicken breasts (42.2%), and drinking water (10%). Almost all Listeria spp. isolates were resistant to more than three classes of antibiotics (multidrug resistant). Besides this, we observed a significant resistance level to penicillin and fluoroquinolone drugs. However, lower resistance levels were recorded for broad-spectrum cephalosporins. The inlA, inlC, and inlJ virulence genes were detected in almost all of the L. monocytogenes isolates. Thus, food safety management approaches and interventions at all stages of the broiler rearing cycle were needed to control cross-contamination and the zoonotic potential of listeriosis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.2
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• pp.234-241
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• 2015

This study investigated the effects of different cooking methods on contents of cholesterol, retinol, and tocopherol in poultry meats (chicken, Korean native chicken, and duck) using saponification extraction and HPLC analysis. The cooking methods were boiling, grilling, stir-frying, deep-frying, steaming, roasting, and microwaving. Generally, contents of cholesterol increased after cooking. Especially, after deep-frying, large amounts of cholesterol were detected from legs of chicken (94.25 mg/100 g) and wings of Korean native chicken (132.96 mg/100 g). High cholesterol content was detected in wings (233.77 mg/100 g) from duck after microwaving. However, contents of retinol decreased after cooking. The retinol contents of breast meat from Korean native chicken were low ($0.86{\sim}0.56{\mu}g/100g$) compared to other meats ($1.10{\sim}22.66{\mu}g/100g$ in chicken and $1.96{\sim}36.80{\mu}g/100g$ in duck), whereas raw materials from wings of all poultry showed the highest tocopherol contents. Of the various cooking methods, stir-frying and deep-frying resulted in increased ${\alpha}$-tocopherol contents in meats.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.11
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• pp.1649-1656
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• 2015

Gene expression profiling has offered new insights into postmortem molecular changes associated with meat quality. To acquire reliable transcript quantification, high quality RNA is required. The objective of this study was to analyze integrity of RNA isolated from chicken skeletal muscle (pectoralis major) and its capability of serving as the template in quantitative real-time polymerase chain reaction (qPCR) as a function of postmortem intervals representing the end-points of evisceration, carcass chilling and aging stages in chicken abattoirs. Chicken breast muscle was dissected from the carcasses (n = 6) immediately after evisceration, and one-third of each sample was instantly snap-frozen and labeled as 20 min postmortem. The remaining muscle was stored on ice until the next rounds of sample collection (1.5 h and 6 h postmortem). The delayed postmortem duration did not significantly affect $A_{260}/A_{280}$ and $A_{260}/A_{230}$ ($p{\geq}0.05$), suggesting no altered purity of total RNA. Apart from a slight decrease in the 28s:18s ribosomal RNA ratio in 1.5 h samples (p<0.05), the value was not statistically different between 20 min and 6 h samples ($p{\geq}0.05$), indicating intact total RNA up to 6 h. Abundance of reference genes encoding beta-actin (ACTB), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), hypoxanthine-guanine phosphoribosyltransferase (HPRT), peptidylprolylisomerase A (PPIA) and TATA box-binding protein (TBP) as well as meat-quality associated genes (insulin-like growth factor 1 (IGF1), pyruvate dehydrogenase kinase isozyme 4 (PDK4), and peroxisome proliferator-activated receptor delta (PPARD) were investigated using qPCR. Transcript abundances of ACTB, GAPDH, HPRT, and PPIA were significantly different among all postmortem time points (p<0.05). Transcript levels of PDK4 and PPARD were significantly reduced in the 6 h samples (p<0.05). The findings suggest an adverse effect of a prolonged postmortem duration on reliability of transcript quantification in chicken skeletal muscle. For the best RNA quality, chicken skeletal muscle should be immediately collected after evisceration or within 20 min postmortem, and rapidly preserved by deep freezing.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.3
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• pp.331-335
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• 1996

A study was conducted to determine the carcass composition of broilers when fed with three varying levels of dietary energy (3,000, 3,200 and 3,400 kcal/kg ME) at 20% crude protein and 0.79% Total Sulphur Amino Acid. The results showed that there was a significant (p < 0.05) increase in the ME intake of the chickens when the ME of the diet increased. Other factors like the protein intake, dressing percentage, weight gain and feed intake were not significantly affected. On the carcass, the increasing dietary ME levels resulted in a significant (p < 0.05) increase in the abdominal fat percentage and carcass fat percentage and a significant (p < 0.05) decrease in the carcass protein percentage. Similarly, the dietary ME produced a significant (p < 0.05) increase in the amount of and fat percentages of breast meat, thigh meat, and drumstick meat with a significant reduction in the protein percentage. There seemed to be an inverse relationship between the percentages of protein and fat. An increase in fat percentages always resulted in similar reduction in the protein content of the meat. These results also showed major differences between the white and red meat of the chicken.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.6
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• pp.912-916
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• 2008

Pre-slaughter conditions affect poultry meat quality. Therefore, stresses before slaughter like heat stress, struggle and shackling on the shackle line, crating and transport and feed withdrawal are very important for the poultry industry in respect of quality as well as welfare of the birds. However, exposure to heat in oxidative stress can in turn lead to cytotoxicity in meat type birds. Chickens exposed to heat stress before slaughter showed the lowest ultimate pH and birds shackled for a longer time the highest. The abdominal fat content was higher in heat stressed birds. Struggling on the shackle line hastened the initial rate of the pH drop and increased the redness of breast meat. Again, with increasing struggling activity, lactate concentration in breast muscle of chicken increased. Paler meat was found in birds that were transported for a longer time than in those after a small journey or not transported. The pre-slaughter and eviscerated weights were decreased as the length of feed withdrawal period increased.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.8
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• pp.1153-1156
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• 2005

An experiment was conducted with three hundred and twenty broiler chickens to evaluate the influence of supplementation of probiotic on growth, microbiological status and carcass quality of chickens. The probiotic contained similar proportions of six strains of variable organisms namely Lactobacillus acidophilus, Lactobacillus casei, Bifidobacterium bifidum, Aspergillus oryzae, Streptococcus faecium and Torulopsis sps and was fed at 100 mg/kg diet. The body weight and feed conversion of probiotic fed groups were superior (p<0.05) compared to the control group in the 4th, 5th and 6th weeks. The chickens fed the diet with probiotic had lower (p<0.05) numbers of coliforms and Campylobacter than chickens fed the control diet. All chickens' carcasses on the control diet were positive for Salmonella while only 16 of the 40 carcasses were positive from chickens fed diets containing probiotic. The leg and breast meat of probiotic fed chickens were higher (p<0.05) in moisture, protein and ash, and lower in fat as compared to the leg and breast meat of control chickens.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.11
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• pp.1608-1614
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• 2014

The objective of this study was to investigate the different dietary ratios of n-6 to n-3 (n-6/n-3) fatty acid (FA) on performance and n-6/n-3 FA in muscles of broiler chickens. A total of 300 one-day-old Cobb chicks were randomly assigned to 3 treatments of 10 replicates in each (10 birds/replicate). Birds were fed on a corn-soybean meal-based diet containing 1% oil during starter (day 1 to 21) and 2% oil during finisher (day 22 to 39) phases, respectively. Treatments of high, medium and low dietary n-6/n-3 FA were formulated by replacing rice bran oil with linseed oil to achieve n-6/n-3 FA close to >20:1, 10:1 and 5:1, respectively. Average daily gain, average daily feed intake, and feed conversion ratio were similar (p>0.05) among the treatments. Serum glucose, cholesterol and triglycerides concentrations were not affected (p>0.05) by dietary treatments. In breast, concentration of C18:3n-3 was significantly greater (p = 0.001) for medium and low vs high n-6/n-3 FA, while concentrations of C20:5n-3, C22:6n-3, total n-3 FA, and n-6/n-3 FA were significantly higher for low vs medium, and medium vs high dietary n-6/n-3 FA. In contrast, concentrations of C18:2 and mono-unsaturated FA (MUFA) were lower for low vs high dietary n-6/n-3 FA. In thigh muscles, concentrations of C20:5n-3 were higher (p<0.05) for medium and low vs high dietary n-6/n-3 FA, and concentrations of C18:3n-3, C22:6, and n-3 FA were greater (p<0.05) for medium vs high, low vs medium dietary n-6/n-3 FA. However, concentrations of C18:1, MUFA, n-6/n-3 were lower (p<0.05) for low and medium vs high dietary n-6/n-3 FA. In conclusion, lowering the dietary n-6/n-3 FA did not affect the performance of chickens, but enhanced beneficial long-chain n-3 FA and decreased n-6/n-3 FA in chicken breast and thigh, which could be advantageous for obtaining healthy chicken products.

• Korean Journal of Poultry Science
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• v.41 no.3
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• pp.151-157
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• 2014

Korean native chicken (KNC) is classified as five lines (grey, black, red, white, brown) based on the plumage colors. The KNC has superior meat quality and flavor compared with those of the commercial broilers, which can be explained by the high arachidonic acid contents. The current study was conducted to investigate arachidonic acid contents in five lines of KNC and used for the development of commercial KNC. Breast and thigh muscles from 597 F1 KNC birds were used in this study and linoleic (precursor of the arachidonic acid) and arachidonic acid contents were measured by the standard protocol. In addition, heritabilities and genetic correlations were estimated. As the results, arachidonic acid contents were significantly different among the KNC lines. Also, relatively high heritabilities (0.414~0.570) for arachidonic acid contents were estimated in both breast and thigh muscles. The estimated genetic correlation was negative between linoleic and arachidonic acids. This study indicated that selection of KNC is possible for improving meat flavor in relation to the arachidonic acid. Also, this study can be used for making breeding plans for commercial KNC in the future.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.4
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• pp.547-552
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• 2002

Characteristics of components related to meat taste of broiler and Korean native chicken (KNC) were investigated. Carnosine was detected much more in the breast meat of KNC at 28 weeks of age and in the leg meat of KNC over 6 weeks of age than broiler. Glutamic acid was much contained in the leg meat of KNC over 11 weeks of age. In the case of breast meat, the content of glutamic acid was higher in KNC over 6 weeks of age than that of others. The ratio of good-tasting amino acid to bitter-tasting amino acid was higher in KNC over 11 weeks of age than broiler. Concentration of IMP in KNC over 15 weeks of age was higher than that of broiler.