• Korean Journal of Poultry Science
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• v.46 no.4
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• pp.279-286
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• 2019

Currently, feather-sexing, which is based on differences in feather development at hatching, is a widely used chick sexing method in the poultry industry. For effective chicken feather-sexing, paternal early-feathering (EF) chickens and maternal late-feathering (LF) chickens must be bred. Therefore, it is critical to identify the effect of EF and LF patterns on production traits in chickens. Thus, the purpose of this study is to analyze and compare the production performances between 522 EF and 232 LF chickens in order to establish the Korean native chicken feather-sexing lines. The results showed that the survival rate of the LF group was significantly higher than that of the EF group from hatching to 52 weeks of age (P<0.05). Body weight, however, was not significantly different between the two groups at all ages. LF and EF groups did not significantly differ in age at first egg laying. However, the hen-day and hen-housed egg production of the LF group were significantly higher than those of EF group (P<0.01). No significant differences were found between the EF and LF groups in all egg quality indicators such as egg weight, eggshell color, albumin height and Haugh unit. Because the breeding target of Korean native commercial chicken is meat-type chicken, feather-sexing strains of Korean native chicken should be established using weighing-based paternal EF lines and laying-based maternal LF lines. Therefore, these results are critical for establishing desirable and effective feather-sexing strains.

• Korean Journal of Poultry Science
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• v.49 no.1
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• pp.1-8
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• 2022

We investigated the effects of stunning methods and gas treatments during slaughter on the quality characteristics of chicken breast and small intestine. Broilers (Ross 308) were stunned and slaughtered using halal, CO₂, or N₂ gas stunning methods (for 10 birds). After slaughter, the pH, proximate composition, color, water-holding capacity, cooking loss, and shear force of chicken breast muscle and small intestine were determined. Compared with the halal treatment, CO₂ treatment resulted in higher pH and lower cooking loss (P<0.05), and the pH, color, and shear force of chicken breast muscle with N₂ treatment were similar to those of the halal treatment (P>0.05). Compared with the halal treatment, the gas treatments resulted in lower pH and lightness and higher redness, yellowness, thickness, and shear force of the small intestine (P<0.05). However, compared with the CO₂ treatment, the N₂ treatment resulted in lower pH, redness, and yellowness, and higher lightness, thickness, and shear force. Overall, compared with the halal method, our results suggest that the use of N₂ gas suppresses the discoloration and deterioration of the texture of chicken meat and small intestine caused by CO₂ gas treatment in the gas stunning method.

• Food Science and Preservation
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• v.16 no.2
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• pp.276-285
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• 2009

This study evaluated the microbiological quality and safety of food items(seafood, meat, eggs, and frozen food) supplied to elementary school food services, during delivery, and analyzed the distribution/delivery system. To this end, 10 food items supplied by 13 factories in Daegu and Gyeongbuk were chosen for study. Beef and pork were delivered directly to schools in freezer vans. Seafood, chicken, and frozen food were delivered to schools by refrigerated vans(${\leq}10^{\circ}C$) that made other delivery stops before arriving at schools. After food was delivered to schools, total bacterial counts and coliforms(respectively) were as follows: mackerel($2.0{\times}10^2-3.2{\times}10^5$, $<5-4.0{\times}10^3CFU/g$), common squid($2.5{\times}10^4-6.6{\times}10^5$, $1.6{\times}10^2-6.0{\times}10^3CFU/g$), shellfish($3.2{\times}10^5-1.7{\times}10^3$, $4.0{\times}10^3-3.0{\times}10\;CFU/g$), boiled fish paste($1.9{\times}10^4$, <5 CFU/g), beef($9.2{\times}10^2-6.4{\times}10^4$, $<5-2.0{\times}10\;CFU/g$), pork($2.6{\times}10^3-1.3{\times}10^6$, $<5-2.7{\times}10^2CFU/g$), chicken($1.0{\times}10^4$, $2.4{\times}10^2CFU/g$), egg($<5-2.3{\times}10^2$, <5 CFU/g), frozen mandu($3.2{\times}10^3-9.5{\times}10^4$, <5 CFU/g), and frozen noodles($<5-9.0{\times}10$, <5 CFU/g). Bacillus cereus($2.0{\times}10\;CFU/g$) and E. coli($1.0{\times}10\;CFU/g$) were detected on shellfish, and Staphylococcus aureuswas detected on pork($3.1{\times}10\;CFU/g$) and chicken($7.8{\times}10\;CFU/g$). Most food items were double-wrapped in vinyl and placed in corrugated cardboard boxes prior to delivery, and the boxes weremixed with other food items when they were put in the vans. There was no cross-contamination during distribution. However, total shellfish bacterial counts increased slightly. These results indicate that foods need to be completely pasteurized during processing. Frozen food items should not be mixed and should be delivered by freezer vans(${\leq}4^{\circ}C$). The number of stops made during distribution/delivery should be reduced.

• Korean Journal of Poultry Science
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• v.45 no.2
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• pp.109-118
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• 2018

A great progress in genetic selection, nutrition and management practices has contributed to the improved growth rate of broilers and egg production in laying hens. For the increased productivity of modern poultry, a healthy chicken liver needs to cope with the increased metabolic demands. The liver is the major site of de novo fatty acid synthesis; therefore, hepatic lipogenesis is crucial for producing better quality meat and eggs. When de novo lipogenesis exceeds the capacity of lipid metabolism and secretion, large amounts of lipids accumulate in the liver of broilers, leading to a fatty liver. Upon onset of egg-laying in hens, lipids including free fatty acids, triglycerides, and phospholipids are dramatically increased in blood plasma for the synthesis of yolk precursors in oocytes. Productive hens with fatty liver often have hemorrhagic syndrome and sudden death due to the heavy demands of yolk synthesis, which burdens the liver. Understanding the lipid metabolism and hepatic lipid disorders is a key point in the improvement of the growth and production of chickens. This review focuses on the recent studies on lipid metabolism, the hepatic lipid disorders, and the prevention or reduction of fatty liver in poultry.

• Korean journal of food and cookery science
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• v.19 no.2
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• pp.144-154
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• 2003

A survey on meal preferences from 693 middle school students was conducted with the objective to enhance the quality of the school food service in Gwangju and the Chollanamdo area. Data were collected by questionnaires and analysed with the SAS program. The most preferred rice was cooked rice; the most unusual meal preference was laver rice; and the most-liked bread was sweet red bean jam bun. The noodle of choice was Tchajangmyon, and the most-liked rice cake was reasoned bar rice cake. The highest ranted korean soups were boiled fish paste soup, kimchi stew, and short rib sour. The most preferred fried meal included fried beef with sweet and sour sauce, and favorite side-dishes were seasoning vinegar squid and kimchi. Yogurt and strawberry were the preferred desserts. A gender difference in preferred foods was seen. The males tended to favor rice with blackish bean sauce, dumpling soup, beef bean curd soup, beef soup, short rib soup, beef bone and tripe soup, hot shredded beef soup, chopped roast chicken, pork roast, roast meat, steamed pork short-ribs, fried port, fried ham, sausage, milk, and yogurt. Males were partial to staple foods and side dishes, The, females favored laver rice, seasoned bar rice cake, bean sprouts soup, fried squid ring, seasoned cucumber, seasoned bean sprouts, fried kimchi, fruits salad, corn salad and citrus fruits. Females tended to choose lighter meals. Meal preference according to residential area showed that, students in Gwangju had more preferences than students in the Chollanamdo area. Classified according to grades, third graders had the greatest meal preference.

• Journal of the Korean Society of Food Culture
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• v.21 no.2
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• pp.142-153
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• 2006

This study was planned to investigate the current using status of agricultural products in school food service both produced in Korea and imported from other countries and the dieticians' perception on using those. A total of 723 dieticians of 442 elementary schools and 381 middle high schools were surveyed in July, 2003 to perform the purposes of the study. A high using rate (93.4%) for Korean agricultural products was investigated. As for meat such as pork and chicken except beef and eggs, the using rate of Korean agricultural products was high. Almost 100% of vegetables and fruits, except tropical fruits such as banana, kiwi, orange and pineapple supplied for school food service were also Korean products. As for nuts and edible oil, the rate of using for Korean agricultural products was comparatively lower than those of other food items due to the price gap. Most dieticians rated the quality of the products produced in Korea higher than that of the imported products in the aspects of their freshness, taste, and safety. But they found no difference in the package condition of the products produced in Korea and of those imported from other countries. This result suggests that the package system should be improved for the agricultural products produced in Korea.

• Animal Bioscience
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• v.37 no.6
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• pp.1041-1052
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• 2024

Objective: Bacillus subtilis, a kind of probiotic with broad-spectrum antibacterial function, was commonly used in livestock and poultry production. Recent research suggested that Bacillus subtilis may have antioxidant properties and improve immune response. This study aimed to verify the probiotic function of Bacillus subtilis in the production of broiler chickens. Methods: A total of 324 (1-day-old) Arbor Acres broilers were selected and randomly divided into three groups: basal diet group (Ctr Group), basal diet + antibiotic growth promoter group (Ctr + AGP) and basal diet + 0.5% Bacillus subtilis preparation group (Ctr + Bac). The experiment lasted for 42 days. Muscle, serum and liver samples were collected at 42 days for determination. Results: The results showed that Bacillus subtilis could decrease malondialdehyde content in the serum and liver (p<0.05) and increase superoxide dismutase 1 mRNA expression (p<0.01) and total superoxide dismutase (p<0.05) in the liver. In addition, compared with AGP supplementation, Bacillus subtilis supplementation increased interleukin-10 (IL-10) and decreased tumor necrosis factor-α and IL-1β level in the serum (p<0.05). At 45 minutes after slaughter Ctr + Bac presented a higher a^* value of breast muscle than Ctr Group (p<0.05), while significant change in leg muscle was not identified. Moreover, there was no difference in weight, shear force, cooking loss and drip loss of breast and leg muscle between treatments. Conclusion: Our results demonstrate that Bacillus subtilis in diet can enhance antioxidant capacity and optimize immune response of broilers.

• Journal of dental hygiene science
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• v.16 no.5
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• pp.361-369
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• 2016

Oral health can influence on diverse food intake, and food intake affect oral health related quality of life. The aim of this study was to select key foods to be able to represent oral health related quality of life in Korea. We used the data of 503 Korean older persons to participate in the oral health promotion programme in 2009. The low consumption or low intake foods with criteria in 2012 National Nutrition Statistics were eliminated among 30 foods of food intake ability (FIA) at first. Decision tree model, correlation analysis, factor analysis, and internal reliablity test were used for oral health related quailty of life (OHRQoL) key food selection. We selected 13 foods-hard persimmon, dried peanut, pickled radish, caramel, rib of pork, glutinous rice cake, cabbage kimchi, apple, yellow melon, boiled chicken meat, boiled fish, mandarin, noodles as OHRQoL Key Foods 13. Thirty foods of FIA and OHRQoL Key Foods 13 displayed the same pattern of variation among sociodemographic groups. In a regression model, both of 30 foods of FIA and OHRQoL Key Foods 13 influenced on oral health impact profile-14. The findings suggest that OHRQoL Key Foods 13 have good reliability and validity and be able to use in oral health survey.

• Food Science of Animal Resources
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• v.30 no.2
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• pp.243-251
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• 2010

This study was conducted to investigate the effects of the addition of cordyceps ochraceostromat, conjugated linoleic acid (CLA) and silkworm cocoon on the quality and storage characteristics of pork sausage manufactured by MDCM (mechanically deboned chicken meat) recovered protein. The samples were divided into 5 groups (sausage made from pork ham; control, 40% of MDCM recovered protein to replace pork ham; T1, 40% of MDCM recovered protein to replace pork ham with 0.1% cordyceps ochraceostromat; T2, 40% of MDCM recovered protein to replace pork ham with 0.1% CLA; T3, and 40% of MDCM recovered protein to replace pork ham with 0.1% silkworm cocoon; T4). The control sample had a higher moisture and protein contents and lower fat content than the other samples during 4 weeks of storage at $4^{\circ}C$ The treatment samples had lower lightness and higher redness values than the control (p<0.05). Hardness, cohesiveness, gumminess and chewiness were significantly lower in the treatment samples than the control (p<0.05). All sausage samples showed a significant increase in thiobarbituric acid reactive substances (TBARS), volatile basic nitrogen, and total plate counts during the storage time (p<0.05). In addition, the MDCM treatment samples had higher TBARS values than the control, but the VBN value of the treatment samples was lower than the control after the 4 weeks storage period.

• Korean Journal of Poultry Science
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• v.50 no.1
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• pp.51-61
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• 2023

This study was designed to evaluate the effects of feral peach (Prunus persica Batsch var. davidiana Max.) sugar extracts (peach extracts) and Gomchwi (Ligularia fischeri) extracts on physicochemical properties of Woorimatdag 1breast marinated with red pepper sauce during cold storage for 18 days. Experimental groups were divided into five groups; CON: marinated breast with basic red pepper sauce, GP15 and GP30: added with 15% and 30% of peach extracts into CON, respectively, GG5 and GG10: added with 5% and 10% of Gomchwi extracts into CON, respectively. Moisture and fat contents of GP30 were lower than those of CON, GG5, and GG10 (P<0.05). Cholesterol content of GP15 was similar to that of CON, while it was lower than the other treatments. GP15 and GP30 showed significantly lower pH than the others. Especially, GP30 showed significantly lower total aerobic bacteria count than other treatment on day 10. During storage, peach and Gomchwi extracts were not significantly effect on meat shear force. Overall acceptability of GP15 was higher than that of GG10 at day 10 and 15 (P<0.05). These results indicated that the treatment of peach extracts has a tendency to improve the storage stability maintaining the sensory preference of marinated Woorimatdag 1 breast compared to Gomchwi extracts. Further study would be needed to identify the specific flavor-enhancing factors of GP treatments.