• Food Science of Animal Resources
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• v.36 no.5
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• pp.594-600
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• 2016

This study aimed to examine the microbial contamination levels in livestock products at retail stores. Beef, pork, and chicken samples from raw materials and final products were obtained between January and December 2015. All homogenized meat samples (25 g) were tested for the aerobic plate count (APC), coliform count (CC), and Escherichia coli count (E. coli). The highest APCs in meat samples, by month, at retail shops were obtained in September, followed by July, May, and October (p<0.001). However, APC was the highest in summer and the lowest in winter (p<0.001). Average APCs for beef, pork, and chicken samples were 2.90, 3.19, and 3.79 Log CFU/g, respectively (p<0.05). A comparison between different months revealed that, CC levels in meat samples ranged from 0 to 1.13 CFU/g, and the highest CC was obtained in August (p<0.001). By season, the highest CC was found in the summer, followed by autumn, and spring (p<0.001). All meat samples were negative for E. coli. The average log₁₀APC and CC for all samples was 3.10 and 0.37 Log CFU/g, respectively. Furthermore, there was a direct correlation between the season and coliform presence (p<0.001). There was also a positive correlation between the APC and CC (r = 0.517, p<0.001). The microbiological APCs for livestock products were in most cases below 10⁶ CFU/g.

• Korean journal of food and cookery science
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• v.20 no.3
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• pp.265-270
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• 2004

To investigate the formation of pyrazines, by-products of chicken were hydrolyzed by protease/peptidase for 4, 8 and 24 hours, after which the hydrolysates were heated with glucose, fructose and xylose, respectively, at l80$^{\circ}C$ for l00min. The formation of pyrazines showed a significant difference by quality and quantity according to the degree of protein hydrolysis. Especially, the formation of 2-methyl pyrazine and 2-ethyl-5-methyl pyrazine was considerably affected by, the degree of protein hydrolysis. Also, 3-ethyl-5-methyl pyrazine, 2-butyl-3-methyl pyrazine, 2-butyl-3,5-dimethyl pyrazine, methyl pyrazine, and 3-ethyl-5-methyl pyrazine were identified only in the hydrolysates for 24 hours.

• Asian-Australasian Journal of Animal Sciences
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• v.4 no.1
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• pp.21-24
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• 1991

A mixed infection of Haemophilus paragallinarum (Hpg), Mycoplasma gallisepticum (MG) and M. synoviae (Ms) was detected in layers of a poultry farm in Iwate prefecture in Japan by pathological, serological and bacteriological investigation. Hpg strains were isolated from three of five birds investigated and all strains were identified to be type C. The Hpg isolates were more susceptible in vitro to a combination of sulfamonomethoxine and ormetoprim (Ektecin) than each of sulfamethoxasol, sulfamonomethoxine, oxytetracycline, tetracycline, streptomycin, erythromycin and thianphinicol. After a total of six days' medication of 1% feed additive Ektecin, symptoms of infectious coryza of hens in the farm almost disappeared and no Hpg was detected even from birds showing nasal discharge.

• Korean Journal of Poultry Science
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• v.40 no.4
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• pp.315-325
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• 2013

In this study, the effects of Doenjang powder (DP : Korean traditional fermented soy bean paste) addition on the quality and shelf-life of chicken sausages during storage were evaluated. The chicken sausages were manufactured with 60% of chicken breast meat, 20% of chicken skin and other ingredients. The sausages were divided into four treatments according to DP addition level such as 0, 2, 5 and 8%. The sausages were vacuum packed and stored at a refrigerator ($5^{\circ}C$) for 4 weeks. pH of sausage was in creased with DP addition after 2 weeks storage (p<0.05). The addition of 2% and 5% DP decreased the lipid oxidation (TBARS) value (p<0.05) and addition of 8% DP seemed to promote the protein deterioration (VBN) over the storage (p<0.05). In the instrumental color, the chicken sausages with 5% and 8% DP showed higher redness and lower lightness value than sausage with 0 and 2% DP (p<0.05) over the storage. The hardness and gumminess of chicken sausages added with 5% DP were significantly lower than those of other treatments during the storage (p<0.05). The addition of DP detained the growth of aerobic and anaerobic bacteria counts after 2 week of storage (p<0.05), but no significant difference was found by DP addition level (p>0.05). In conclusion, 5% DP could be used as ingredient of chicken sausage to enhance sensory quality and retard lipid oxidation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.6
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• pp.761-767
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• 2006

To determine freshness and quality change of chicken products during storage, we manufactured freshness indicator and monitored the surface pH, volatile basic nitrogen (VBN), thiobarbituric acid reacted substance (TBARS), total bacterial counts, electronic nose analysis, and sensory evaluation. All chicken products (drum, wing, thigh) had a change in color of freshness indicator after storage of 3 days at $4^{\circ}C$, indicating poor quality at the time. VBN, TBARS values, and total bacterial counts reached the decay point at the time of color change of freshness indicator attached to the surface of chicken samples. The sensory evaluation also indicated sample was not acceptable by off-odor at day 4 of storage. According to electronic nose analysis to examine off-odor, there were significant differences in terms of principal component analysis values among chicken samples of day 0, day 3, and day 5 of storage. These results suggest that freshness indicator should be useful in determining expiration date of chicken products during marketing by indicating the microbial safety as well as physicochemical and sensory change.

• Food Science of Animal Resources
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• v.32 no.3
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• pp.316-322
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• 2012

This study was conducted to evaluate the effects of soaking pH and extraction temperature on the physicochemical properties of chicken skin gelatin. In order to extract gelatin from chicken skin, the chicken skin was soaked at various pH ranges (1-13) and was extracted at 75 and $100^{\circ}C$. For the rate of weight increase, the highest value was obtained from two pH ranges (1-2 and 12-13). In addition, the rate of weight increase was affected by soaking time. The alkali treatments had greater crude protein content as well as total extraction yield compared to the acid process (p<0.05), and the increased extraction temperature resulted in a significant (p<0.05) increase of crude protein content and total extraction yield. All treatments showed ${\alpha}1$ and ${\alpha}2$ chains derived from type I collagen on SDS-PAGE. The pH value and color of gelatin gel (6.67%) were affected by soaking pH and extraction temperature. Chicken skin gelatin gel extracted at $75^{\circ}C$ after soaking at a pH of 2 had the highest melting point (p<0.05) and gel strength among all treatments. Although the chicken skin treated with the alkali process had a higher yield, a lower extraction temperature following the acid process would be better for obtaining superior gelatin from chicken skin.

• Korean Journal of Food Science and Technology
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• v.18 no.2
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• pp.88-92
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• 1986

Determination of bacterial adenosine triphosphate (ATP) based on luciferin-luciferase bioluminescene reaction was applied to the measurement of bacteria on the surface of chicken as an alternative rapid method. The light yield was proportional to the concentration of ATP giving a straight line within a range of $10^{-10}\;to\;10^{-6}M$. The bacteria isolated from the surface of chicken were identified as Escherichia coli, Hafnia alvei, Pseudomonas putida and Aeromonas hydrophila. When the ATP contents of each bacteria were determined by bioluminescence reaction and compared, there was no significant difference (r = 0.95). The Patterns of growth curves for E. coli look very similar, when the bacterial growth was monitored by ATP content and viable cell count. When bacterial ATP of each samples collected every 2 days during storage for 14 days at $4^{\circ}C$was determined and compared with viable cell count, it gave a good correlation (r = 0.95, n = 32).

• Food Science of Animal Resources
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• v.35 no.1
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• pp.101-107
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• 2015

The aim of this study was to investigate the effects of various marination processes on the quality characteristics of chicken breast prepared with chicken feet gelatin and wheat fiber. The chicken feet gelatin was swollen with hydrochloric solution (0.1 N HCl, pH $1.31{\pm}0.02$) and dehydrated by freeze-drying. The composition (w/w) of the marinade was water (10%), soy sauce (12%), phosphate (0.3%), wheat fiber (1.5%), and chicken feet gelatin (1.5%). Three samples of chicken breast were manufactured with Tumbler (only tumbler), Tenderizer (tenderizer and tumbler), and Injector (injector and tumbler). The water content of the Injector sample was significantly higher than those of the Tumbler and Tenderizer samples (p<0.05). During heating, the lightness of all chicken breasts increased and the redness decreased. The tumbling and cooking yield of the Injector sample were significantly higher than those of the Tumbler and Tenderizer samples (p<0.05). The shear force of the Tenderizer sample was significantly lower than that of the Tumbler and Injector samples (p<0.05). No significant differences, except for color, were observed in the sensory analysis of the samples. Thus, the proper selection of mechanical processing is important to improve the quality characteristics of marinated chicken breast, considering the types of final products.

• Food Science of Animal Resources
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• v.32 no.5
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• pp.618-626
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• 2012

Citrus (Citrus unshiu S. Marcoy) industry by-products were used as a source of dietary fiber, and the effects of dietary fiber extracted from citrus peel on the proximate composition, pH, color, protein solubility, cooking loss, emulsion stability, and apparent viscosity of a chicken emulsion in model systems were examined. Chicken emulsions were prepared by adding citrus peel fiber at four different concentrations (1, 2, 3, and 4%). The apparent viscosity, redness, and yellowness of the chicken emulsion with citrus peel fiber were higher than those of the control (p<0.05). The lightness values of the chicken emulsions were lower in treatments containing citrus peel fiber (p<0.05). Furthermore, moisture content, cooking loss, and emulsion stability of the chicken emulsion with 1-2% citrus peel fiber were higher than those of other treatments (p<0.05). Fat content was lower in the treatments with added citrus peel fiber than that in the control (p<0.05). Chicken emulsions with added citrus peel fiber had improved quality characteristics, and the best results were obtained for the chicken emulsion with 2% added citrus peel fiber.

• Preventive Nutrition and Food Science
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• v.10 no.2
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• pp.122-129
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• 2005

Chlorine dioxide $(ClO_2)$ treatment was evaluated for microbial growth inhibition and its effects on the quality of vacuum-packaged chicken breasts. Chicken breast samples were treated with 3, 50, and 100 ppm of $ClO_2$ solution, respectively. After $ClO_2$ treatment, chicken breast samples were individually vacuum-packaged and stored at $4^{\circ}C$, a typical storage temperature for meat and meat product, for 7 days. The vacuum-packaged chicken breasts treated with $ClO_2$ had significantly lower total bacteria, yeast and mold, total coliform, and Salmonella spp. were significantly reduced by $ClO_2$ treatment. $D_{10}-values$ of total bacteria count, yeast and mold, total coliform, and Salmonella spp. in vacuum-packaged chicken breasts was 93, 83, 85, and 50 ppm, respectively. The pH of vacuum-packaged chicken breasts decreased with increasing $ClO_2$ concentration. Thiobarbituric acid reacted substance (TBARS) values of vacuum-packaged chicken breasts increased during storage, regardless of $ClO_2$ concentration. $ClO_2$ treatment caused negligible changes in Hunter L, a, and b values in the vacuum-packaged chicken breasts. Sensory evaluation of the vacuum-packaged chicken breasts showed that there were no significant changes among the samples treated with various $ClO_2$ concentration. These results indicate that $ClO_2$ treatment could be useful in improving the microbial safety and quality of meat products.