• Journal of Animal Science and Technology
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• v.55 no.3
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• pp.219-227
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• 2013

This study was conducted to elucidate the characteristics of equine meat traits and to evaluate the utilization of dried-citrus pulp abundantly produced in Jeju Island as feed ingredient in the diet of finished meat horses. Treatment groups consisted of wheat bran (A) and the dried-pellet mixture of citrus pulp (20%) and wheat bran (80%) (B). Feeding of agricultural by-products were 2 times in a day at the level of 1.5% of body weights. Water and dried-grass forage was not restricted. The average daily gain was similar in both groups. Feed conversion of treatment B showed lower level than that of A. Carcass rate of B was relatively lower than that of A, but meat yield grade of B was higher than that of A. For meat color traits, $L^*$ of B was lighter than that of A, and $b^*$ of group B was lower than that of group A. From the analysis of physical characteristics of equine meats, shearing force had decreased in the treatment B but the levels of drip loss and water holding cavity had increased in the treatment B compared to A. The level of crude fat is lower in the treatment B than the treatment A. For the mineral contents, the treatment B showed higher levels of Ca, K, Mg, Cu and Mn than that of A. For the fatty acid contents, the treatment B showed increased levels of stearic acid, oleic acid, eicosenoic acid, and arachidonic acid compared to A. Consequently, these results suggested that dried-citrus pulp might be utilized as replacement material for equine forage. Please rewrite the whole abstract and should include all required information. Before resubmission, please check it again from a native colleague in your group.

• Food Science of Animal Resources
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• v.24 no.4
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• pp.319-325
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• 2004

The objective of the present study was to investigate the effect of processing conditions on the physical and sensory properties of pork cutlet produced from chilled pork loin (T1), the cured and massaged chilled pork loin (T2), the cured and massaged frozen pork loin (T3), frozen pork loin (T4), massaged frozen pork loin (T5). Water holding capacity (WHC) of pork cutlets were not significantly different among the treatments. In chilled pork loin, WHC of T2 were slightly higher than that of T1. T4 showed the lowest WHC among all treatment group. In meat color, CIE L$\^$*/, a$\^$*/. b$\^$*/ values in chilled pork loin were not significantly different between T1 and T2. L$\^$*/ values of T3 and T5 were higher than that of T4. a$\^$*/ values were not significantly different among the all treatments. T3 produced through the curing and massaging treatment showed the highest tenderness in shear force (p< 0.001), while force value (kg/㎤) of T4 were the highest among all treatments. Separation ratio of wheat dough from pork cutlet was highest (p.<0.001) in T4. In triangle test, T1 : T3 combination was higher than that of other pairs. No differences in acceptability of sensory evaluation were observed among T1, T2, T3, and T5 groups, while the frozen pork showed the lowest (p<0.001) acceptability. In conclusion, pork cutlets from T4 with the curing and/or massaging process showed similar acceptance than those from chilled pork loins, and this treatments may contribute to promote the consumption of frozen pork loins.

• Korean Journal of Poultry Science
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• v.43 no.4
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• pp.235-242
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• 2016

This study was conducted to investigate the microbiological sanitation status of raw chicken meat distributed in Korea, and potential changes in chicken breast quality during storage. The microbiological sanitation status analysis of raw chicken involved studying the results of microbiological monitoring for a 5-year period (2010~2014) by the Korean Food and Drug Administration. Furthermore, the microbiological status of raw chicken meat in meat packing centers and shops in Seoul/Gyeonggi, Kangwon, and Chungcheong Provinces was investigated from July to August 2015. The total bacterial counts of chicken meat in the packaging centers and meat shop of these Provinces were below the level specified in the Korean Meat Microbiological Guideline ($1{\times}10^7$ colony forming units [CFU]/g) and showed a similar microbiological sanitation status with results of the microbiological monitoring for the analyzed 5-year period. To evaluate the relationship between quality change and microbiological level of the meat distributed in Korea, the pH and microbiological and sensory quality characteristics of the chicken breast samples during storage at $4{\pm}2^{\circ}C$were determined. On day 4, the total bacterial count of the chicken breast was 6.76 log CFU/g, which was close to the official $1{\times}10^7CFU/g$ standard, the pH was 5.96, and the overall acceptability was reduced significantly (p<0.05). In particular, the aroma score was <5, indicating that the consumer panel expressed a negative perception even though the chicken contained a lower microbial level than that specified in the Korean microbiological guideline. These results suggest that the current Korean microbiological guideline for raw chicken meat may require a stricter level of up to $1{\times}10^6CFU/g$ to satisfy both meat safety standards and organoleptic quality for consumers.

• Journal of Life Science
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• v.25 no.7
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• pp.740-747
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• 2015

This study was carried out to evaluate changes in the meat quality and antioxidation activity in the loin and ham of Korean Native Black Pigs (KNBP) during frozen storage at −18℃ for 150 days. The pH value of the loin was decreased as storage days progressed, while the pH value of the ham showed no consistent changes with storage days. The lightness (L*) of the loin did not show any significant reduction until day 120, whereas L* of the ham was significantly declined throughout the storage period (p<0.05). The redness (a*) values of the loin and ham were significantly decreased as storage progressed. The water holding capacity of the loin was decreased by day 30 and that value was maintained until the end of storage. The initial total numbers of microorganisms in the loin and ham were 4.88 and 5.16 Log CFU/g, respectively and these numbers were significantly decreased by day 30 (p<0.05). The levels of 2-thiobarbituric acid reactive substances (a measurement of lipid oxidation) in the loin and ham ranged from 0.057-0.069 and 0.052-0.087 mg MDA/kg meat, respectively, until storage day 150. Volatile basic nitrogen values of the loin and ham ranged from 15.13-16.55 and 16.05-16.23 mg%. Oxygen radical absorbance capacities and carnosine contents of the loin and ham were significantly decreased during frozen storage for 3 months (p<0.05). In summary, the meat quality of the loin and ham from KNBP was somewhat decreased during frozen storage. However, the levels of antioxidants and dipeptides with antioxidant activity were significantly decreased in pork loin and ham during frozen storage.

• Journal of Life Science
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• v.22 no.11
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• pp.1477-1486
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• 2012

This study was performed to determine the effect of onion peel extract using 70% ethanol and 95% ethanol on its anti-oxidation activity, small intestine length, and intestinal villi of high-fat fed mice. Five percent of each onion peel extract using 70% and 95% ethanol showed significant decrease of E. coli and Listeria monocytogenes. Total phenolic contents of onion peel extracts using 70% and 95% ethanol were $166.89{\pm}0.03$ mg/g and $160.89{\pm}0.13$ mg/g, respectively. In anti-oxidation activity, DPPH radical scavenging activity and SOD-like activity of onion peel extracts were higher at 100 ug/ml concentration. The obese mice were fed high-fat diets supplemented by 1, 3, and 5% of the onion peel extracts using 70% and 95% ethanol for 4 weeks. Body weight, feed intake, feed efficiency, small intestine weight, length, villi's length, and number of bacteria in intestine were determined. Body weight of mice fed 5% of onion extracts using both 70% and 95% ethanol was significantly lower than that of control (p<0.05). However, feed intake was increased in mice fed 5% of onion extracts at both fermented ethanol levels. Small intestine weight and length of mice showed no significant change with supplementation of the onion peel extracts. However, length of small intestine villi was significantly longer than that of control. Total bacteria counts of Cl. Perfringenes and E. coli in small intestine of the mice were significantly reduced by supplementation of 5% of onion extract using ethanol, while lactic acid bacteria were increased. These results suggest that 5% of onion peel extracts using ethanol at either 70% or 95% concentration have potential to be used as an additive for body weight control and enhanced gut health; however, more research on its effectiveness is needed.

• Food Science of Animal Resources
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• v.33 no.2
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• pp.258-267
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• 2013

This study was conducted to determine the antioxidative and neuroprotective effect of pig skin extracts (PS) and pig skin gelatin hydrolysates (LPS) using a human neuroblastoma cell line (SH-SY5Y). The extraction yield of PS was 3 fold higher than that of LPS. The protein content of PS was about 10 fold higher than that of LPS (p<0.05). Also LPS increased antioxidative activity dose dependently, and the activity was significantly higher than PS at all concentration (p<0.05). DPPH radical scavenging activity of LPS at 50 mg/mL was 92.97%, which was similar to $1{\mu}M$ vitamin C as a positive control. ABTS radical scavenging activity of LPS (20 mg/mL) was 89.83% and oxygen radical absorbance capacity of LPS at 1 mg/mL was $141.39{\mu}M$ Trolox Equvalent/g. No significant change of human neuroblastoma cells was determined by MTT test. Cell death by oxidative stress induced by $H_2O_2$ and amyloid beta 1-42 ($A{\beta}_{1-42}$) was protected by LPS rather than PS. Acetylcholine esterase was significantly inhibited, by up to 33.62% by LPS at 10 mg/mL. Therefore, these results suggest that pig skin gelatin hydrolysates below 3 kDa have potential to be used as anti-oxidative and neuroprotective functional additives in the food industry, while further animal test should be determined in the future.

• Journal of Life Science
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• v.23 no.12
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• pp.1477-1485
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• 2013

The aim of this study was to evaluate changes in the meat quality and natural di-peptide (carnosine and anserine) content in the loin and ham cuts of female, Korean Native Black Pigs (KNBP) during cold storage for 10 days. The pH value of the loin and the ham cuts increased with an increase in the number of storage days. The lightness ($L^*$) of the loin cuts did not show any significant difference; however, the lightness of the ham cuts was decreased at storage day 10 (p<0.05). The redness ($a^*$) of the ham was higher than the redness of the loin (p<0.05) during the entire 10-days of storage. The water holding capacity of the loin was decreased from 78.5% to 67.9% during storage (p<0.05). The total number of microorganisms and coliforms was increased in both the loin and the ham during storage, and the initial total microbial contamination was higher in the ham cut (5.16 log CFU/g) than it was in the loin cut (4.87 log CFU/g). The carnosine content of the loin and the ham was in the range of 1.12-1.35 mg/ml and no significant difference was found between those two pork cuts. The anserine content of the ham cut was higher than it was in the loin cut until storage day 3. The ratio of carnosine and anserine increased with an increase in the number of storage days and it ranged from 27.6-59.7 for the loin cut and from 20.1-51.2 for the ham cut. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of the loin and the ham cuts significantly decreased as the number of storage days increased. For both types of KNBP cuts, lipid oxidation and volatile basic nitrogen significantly increased after storage day 5. These results found that natural antioxidants carnosine and anserine decreased as the number of storage days increased, and anserine decreased more rapidly than carnosine (p<0.05).

• Korean Journal of Poultry Science
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• v.45 no.4
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• pp.261-272
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• 2018

This study was conducted to evaluate the difference in the quality of chicken thigh meat from conventional and animal welfare farms during refrigeration storage over 9 days. Chicken thigh meat from conventional (CTC, n = 30) and animal welfare farms (CTW, n = 30) was tested. The pH value was significantly lower in CTW (6.28) than in CTC (6.37) on day 1; however, no significant differences were found on subsequent days. The yellowness of CTW was higher than that of CTC on day 1, but CTW showed lower yellowness than did CTC on day 7 and 9. The cooking loss, water holding capacity, lightness, redness, and coliform levels of CTC did not show any significant difference when compared with CTW during storage. The shear force of CTW was significantly higher than that of CTC on day 1, 3, 7, and 9. Total microorganism and coliform in CTC and CTW increased with increasing storage days. On day 7 and 9, the total microorganism level of CTW was lower than that of CTC. The thiobarbituric acid value of CTW was lower than that of CTC on day 9. The volatile basic nitrogen (VBN) of CTW was lower than that of CTC during storage. Anserine content and 1,1-diphenyl-2-picryl-hydrazyl(DPPH) scavenging activity of CTW was significantly higher than CTC on day 1. These results suggest that CTW stayed fresher for longer than did CTC because of low total microorganism level on day 7 and 9, and VBN during refrigerated storage.

• Journal of Science Education
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• v.42 no.3
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• pp.371-389
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• 2018

This study focuses on the fact that students and teachers commonly have difficulty in 'selecting the topic' in many activities including student-led research that is conducted from topic selection to the drawing of conclusion. The purpose of this study is to develop a manual for science teaching research. The instructional manuals of 4 stages were developed based on practical knowledge that can be implemented in the actual class through previous research and literature. Each stage is composed of , , , and . In the third stage, students are expected to find scientific questions and develop them into research topics through detailed class research on newspaper articles, scientific magazines, traditional knowledge, proverbs, daily life, and textbook experiments. In the experimental group, the final research topic was selected through a variety of sources such as textbook experiments, proverbs, YouTube images, newspaper articles, individual WHY NOTEs, and understood the conditions of the scientific research topic and expressed the variables in the research title. However, in the control group, some students did not consider the research scope of the selected research subjects to be specific or not to be able to study at their level. As a result of giving the students as much autonomy as possible, many groups did not fully understand the previous research and submitted it. Based on the results of this study, it can be concluded that development and use of a 'topic selection stage' centered practice manual for general high school teachers would not only improve the students' abilities to discover solutions to scientific questions, but it will also help shift their attitudes towards science in a positive direction.

• Korean Journal of Poultry Science
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• v.46 no.3
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• pp.137-154
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• 2019

This study was conducted to develop and compare Samgyetang broth from extract of pre-treated chicken feet. Chicken feet were subjected to non-heating (control), heating at $70^{\circ}C$ for 12 h in a hot air dryer, and heating at $180^{\circ}C$ for 1 h in an oven. The heat-treated chicken feet were extracted at $121^{\circ}C$ for 1 h and 2 h, respectively. The extract was placed in a pouch with whole chicken carcass ($470{\pm}10g$). The sealed Samgyetang retort was made according to the industrial method. The pH of the extract from preheated chicken feet was lower than that extracted from fresh chicken feet. The Thiobarbituric Acid Reactive Substances (TBARS) value of the preheated chicken feet extract was significantly lower (P<0.05) than that of fresh chicken feet extract, but there were no significant differences among the broths. As the extraction time increased, the pH and TBARS value decreased in the extract (P<0.05) but increased in the broth (P<0.05). According to the sensory evaluation test, the extract from 1 h hot air heating and drying was significantly better in appearance, aroma, and overall preference than the other treatments (P<0.05). The GC-MS results showed that benzaldehyde and benzothiazole, which are widely known to give meat and nuts flavor, were detected in those treatments (P<0.05). The Samgyetang broths prepared from 1 h hot air heating and drying extract were significantly higher in the overall acceptability according to the sensory test (P<0.05). In summary, the quality of retort Samgyetang broth can be improved by adding chicken feet extract which is subjected to heating and drying for 1 h.