• Asian-Australasian Journal of Animal Sciences
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• v.30 no.7
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• pp.1029-1036
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• 2017

Objective: In the livestock industry, the regulatory mechanisms of muscle proliferation and differentiation can be applied to improve traits such as growth and meat production. We investigated the regulatory pathway of MyoD and its role in muscle differentiation in quail myoblast cells. Methods: The MyoD gene was mutated by the clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 technology and single cell-derived MyoD mutant sublines were identified to investigate the global regulatory mechanism responsible for muscle differentiation. Results: The mutation efficiency was 73.3% in the mixed population, and from this population we were able to establish two QM7 MyoD knockout subline (MyoD KO QM7#4) through single cell pick-up and expansion. In the undifferentiated condition, paired box 7 expression in MyoD KO QM7#4 cells was not significantly different from regular QM7 (rQM7) cells. During differentiation, however, myotube formation was dramatically repressed in MyoD KO QM7#4 cells. Moreover, myogenic differentiation-specific transcripts and proteins were not expressed in MyoD KO QM7#4 cells even after an extended differentiation period. These results indicate that MyoD is critical for muscle differentiation. Furthermore, we analyzed the global regulatory interactions by RNA sequencing during muscle differentiation. Conclusion: With CRISPR/Cas9-mediated genomic editing, single cell-derived sublines with a specific knockout gene can be adapted to various aspects of basic research as well as in functional genomics studies.

• Korean Journal of Community Nutrition
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• v.4 no.1
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• pp.46-56
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• 1999

A deep understanding of the dietary patterns and nutrient intake is important for assessment of possilbe nutritional risk and for establishing nutrition improvement strategies. This study was conducted toexamine the dietary characteristics of a nutritionally poor elderly group compared to the middle-and highly-nourished group. Elderly participant was recruited from local elderly centers in Suwon city in 1998. Trained dietitians interviewed 119 elderly(35 males, 84 females) aged 60 years and over for collecting dietary data(24-hour recall) and related variables. Male and female subjects were grouped into high, middle, and low according to the mean nutrient adequancy ratio(MAR) tertiles. An analysisof the percentage of RDA(Recommended Daily Allowances of Korea) for each of the 10 nutrients showed that the male low-MAR group consumed below the RDA in all kinds of nutrients, and the female low-MAR group consumed nutrients below the RDA except vitamin C. An evaluation of nutrient density by Index of Nutritonal Quality(INQ) also showed a similar tendency. Thus, the INQ level of the male low-MAR group was significantly lower than the middle-or high-MAR group, especially in protein, vitamin A, thiamin, riboflavin, and phosphorus(p<0.05). Moreover, INQ level of female low-MAR group was significantly lower than that of the high group(p<0.05) in all nutrients. The female low-MAR group's daily food intake were also lower than those of the high-MARgroup in gains, fish, fruits, oil and beverages. The energy distribution from carbohydrates, fats and proteins showed that the male low-MAR group had significantly higher carbohydrate and lower fat proportions compared to each gender high-MAR group, respectively. The male and female low-MAR group had low scores about eating all side dishes. These findings indicate that a moderate increase of the meat/egg/fishes intake was needed by the male low-MAR group for improving nutrition adequacy, and an overall increase of the food quantity and quality was desired for the female low-MAR group. These data could be used for planning a community elderly nutrition program and establishing strategies for tailored guidelines for the individuals.

• Nutrition Research and Practice
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• v.13 no.6
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• pp.480-487
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• 2019

BACKGROUND/OBJECTIVES: Osteoarthritis (OA) is a major public health issue in Japan and other countries, and foods that prevent or treat OA are in strong demand. Proteins and peptides in chicken meat and bones are known for being rich in functional and nutritional ingredients for the improvement of osteoporosis. We speculated that chicken legs, a food consumed in many regions of the world, may also contain such ingredients. In this study, we aim to (i) evaluate the effect of chicken leg extract (CLE) on the promotion of cartilage matrix production and (ii) identify the active ingredient in CLE that contributes to this function. MATERIALS/METHODS: Artificial CLE digest was prepared, and the acid mucopolysaccharide production-promoting activity of the CLE digest was evaluated by alcian blue staining of ATDC5 cells. CLE was orally administered to rabbits with burr holes in the knee joint of the femur, and the degree of regeneration of cartilage matrix was evaluated. Furthermore, we investigated orally administered CLE-derived peptides in human plasma using LC-MS. From measuring the acid mucopolysaccharide production-promotion activity of these peptides, a molecule considered to be an active ingredient in the CLE digest was identified. RESULTS: CLE digest promoted acid mucopolysaccharide production and facilitated regeneration of cartilage matrix in in vitro and in vivo experiments. Four peptides including phenylalanyl-hydroxyproline (Phe-Hyp) were detected as CLE-derived peptides in human plasma. The effect of CLE was inferred to be due to Phe-Hyp, which was confirmed to be present in the CLE digest. CONCLUSIONS: It was shown that CLE stimulated the production of articular cartilage matrix both in vitro and in vivo, and that CLE could be an effective food for preventing or treating OA. Furthermore, only Phe-Hyp was confirmed as the active compound in the CLE digest, suggesting that the activity of CLE was due to Phe-Hyp.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.4
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• pp.505-511
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• 2023

This study investigated the effect of transglutaminase (TGase) and polysaccharide kappa carrageenan on the texture, chemical, and microbiological qualities of refrigerated unmarketable rainbow trout Oncorhynchus mykiss. Gel strength increased substantially in TGase-treated samples, and was adding kappa carrageenan resulted in no significant difference. SDS-PAGE results confirmed that the myosin heavy chain band with a molecular weight of 205-250 kDa was weakened in trout meat treated with 1% TGase, which led to cross-linking reactions between proteins. The volatile basic nitrogen (VBN) increased in all samples during storage at 4℃ for 10 days; however, the samples treated with 0.5% and 1% kappa carrageenan had the lowest VBN. The viable cell count increased in all samples treated with TGase and kappa carrageenan; however, an increase in TGase enzyme and kappa carrageenan concentration successfully hindered total bacteria growth. Thus, adding 1% TGase and 1% kappa carrageenan to refrigerated unmarketable rainbow trout formulations can optimize quality characteristics.

• Journal of Animal Science and Technology
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• v.65 no.5
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• pp.1065-1080
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• 2023

The solubility and structure of myosin and the properties of pork gel with NaCl, KCl, CaCl₂, and MgCl₂ were investigated. Myofibrillar proteins (MPs) with phosphate were more solubilized with NaCl than with KCl (p < 0.05). CaCl₂ and MgCl₂ showed lower MP solubilities than those of NaCl and KCl (p < 0.05). The α-helix content of myosin was lower in KCl, CaCl₂, and MgCl₂ than in NaCl (p < 0.05). The pH of pork batter decreased in the order of KCl, NaCl, MgCl₂, and CaCl₂ (p < 0.05). The cooking yield of the pork gel manufactured with monovalent salts was higher than that of the pork gel manufactured with divalent salts (p < 0.05). The pork gel manufactured with KCl and MgCl₂ showed lower hardness than that of the pork gel manufactured with NaCl. The solubility and structure of myosin were different with the different chloride salts and those led the different quality properties of pork gel. Therefore, the results of this study can be helpful for understanding the quality properties of low-slat meat products manufactured by replacing sodium chloride with different chloride salts.

• Animal Bioscience
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• v.37 no.2
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• pp.284-294
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• 2024

Objective: Pork is an important source of animal protein in many countries. Subtle physiochemical changes occur during pork postmortem aging. The changes of apoptosis and autophagy in pork at 6 h to 72 h after slaughter were studied to provide evidence for pork quality. Methods: In this article, morphological changes of postmortem pork was observed through Hematoxylin-eosin staining, apoptotic nuclei were observed by TdT-mediated dUTP nick end labeling assay, protein related to apoptosis and autophagy expressions were tested by western blot and LC3 level were expressed according to immunofluorescence assay. Results: In this study, we found the occurrence of apoptosis in postmortem pork, and the process was characterized by nucleus condensation and fragmentation, formation of apoptotic bodies, increase in apoptosis-related Bax/Bcl-2 levels, and activation of caspases. Autophagy reached its peak between 24 and 48 h after slaughter, accompanied by the formation of autophagosomes on the cell membrane and expression of autophagy-related proteins beclin-1, P62, LC3-I, LC3-II, and ATG5. Conclusion: Obvious apoptosis was observed at 12 h and autophagy reached its peak at 48 h. The present work provides the evidence for the occurrence of apoptosis and autophagy during postmortem aging of pork. In conclusion, the apoptosis and autophagy of muscle cells discovered in this study have important implications for pork in the meat industry.

• Food Science of Animal Resources
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• v.29 no.2
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• pp.151-156
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• 2009

The prevalence of food allergies was investigated using questionnaires with 300 subjects whose ages ranged from 19 to 24 years old and the causative food allergens was analyzed using immunological analysis with serum of the subjects who answered that they have/had food allergy. The questionnaire showed that 11.33% of subjects have/had experience of food hypersensitivity, where the main causative foods were fish, beef, chicken, milk, egg, and pork in order. The meat allergy shared 4.65% (2.33% for beef, 1.66% for chicken, 0.66% for pork) in the prevalence of food allergies. The causative beef allergens were investigated with the serum of 6 subjects who have had beef allergy. Western blots were carried out with the serum of P6 subject who showed a positive reaction to beef extract in ELISA. The two specific bands were detected in beef extract on the PVDF membrane, and no band was detected in extracts of pork and chicken. A calculation of the distance of migration by SDS-PAGE enabled the molecular masses of the two bands to be estimated as 67kDa and 31kDa, respectively. The 67kDa was revealed as bovine serum albumin (BSA) which is one of the important beef allergens as reported previously though an analysis of the N-terminal amino acid sequence. However we could not identify the sequence of 31kDa, probably because they comprised several subunits and were modified proteins such as glycoprotein that were unlikely to be easily degraded by the Edman method. The 31kDa band were dyed with the PAS (periodic acid-schiff reagent), suggesting that it might be a glycoprotein. These results suggested that the 31kDa might be considered as a novel potential beef allergen which is not reported previously, although further studies are needed.

• Journal of Nutrition and Health
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• v.57 no.1
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• pp.153-169
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• 2024

Purpose: The main goal of this study was to identify the impact of coronavirus disease 2019 (COVID-19) on grocery purchases (i.e., fresh and processed foods by grain, vegetable, fruit, seafood, and meat categories) in Korea. To understand the specific impact of COVID-19, the study period was divided into 3 segments: PRE-COVID-19, INTER-COVID-19, and POST-COVID-19. Methods: We used the microdata of household income and expenditure from Statistics Korea (KOSTAT), representing households across the country. The data comprised monthly grocery expenditure data from January 2019 to September 2022. First, we compared the PRE-COVID-19 period to INTER-COVID-19 and then INTER-COVID-19 to POST-COVID-19 and used multiple regression analysis. The covariates used were the gender and age of the head of the household, the household's monthly income, the number of family members, the price index, and the month (dummy variable). Results: The expenditures on all grocery categories except fresh fruit increased from PRE-COVID-19 to INTER-COVID-19. From INTER-COVID-19 to POST-COVID-19, almost all grocery category spending declined, with processed meat being the only exception. Most purchases of protein sources, increased during INTER-COVID-19 compared to PRE-COVID-19, while ham/sausage/bacon for meat protein, fish cakes and canned seafood for seafood protein, and soy milk for plant-based protein did not decrease during POST-COVID-19 compared to INTER-COVID-19. Conclusion: These results show an overall increase in in-home grocery expenditure during COVID-19 due to an increase in eating at home, followed by a decrease in this expenditure in the POST-COVID-19 period. Among the trends, the protein and highly processed convenience food categories did not see a decline in spending during the POST-COVID-19 period, which is a reflection of the preferences of consumers in the post-COVID-19 period.

• Korean Journal of Agricultural Science
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• v.45 no.1
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• pp.84-93
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• 2018

This study was conducted to develop a pasture feeding program for reducing the Hanwoo feeding cost. Italian ryegrass (IRG) is a major plant which is abundantly produced in the southern area of South Korea. Locally produced Italian ryegrass has a 30 - 50% reduced pasture cost compared to imported pasture grasses. We hypothesized that Italian ryegrass feed could reduce the feeding cost but not change the physiological characteristics of the Hanwoo steers in the feedlot. Four treatments (Control, short fed IRG silage, long fed IRG silage, and IRG hay) in a completely random design were used to feed 27 Hanwoo steers. Three or four steers were fed in the same pen, and 8 pens were used for the treatments. Blood was drawn from each steer on the first week of every month from 11 to 30 months. Overall, the average daily gain and feed efficiency were not different among the treatments (p < 0.05) except for the final fattening diets (p < 0.05). The long fed IRG silage group had a low ADG compared to the other groups (p < 0.05). The serum non-esterified fatty acid and glucose concentrations were reduced during the fattening periods (p < 0.05); however, the serum albumin, total proteins, triglycerides, and phosphorus were increased during the fattening periods (p < 0.05). The carcass weight, longissimus muscle area and back-fat thickness were low in the long fed IRG silage group (p < 0.05). The IRG diet induced saturated fatty acids in the longissimus dorsi (p < 0.05). These results show that the IRG diet increased the serum triglycerides but reduced the glucose level at the final fattening diet and decreased the meat yield score in Hanwoo steers.

• The Korean Journal of Food And Nutrition
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• v.22 no.4
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• pp.669-677
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• 2009

The purpose of this study was to compare the anthropometry, nutrient intakes, dietary - related behaviors and health - related behaviors of male workers that were divided according to their alcohol consumption. The mean height, weight and BMI of all subjects were 172.0$\pm$5.8 cm, 67.8$\pm$9.3 kg and 22.9$\pm$2.6 kg/$m^2$, respectively. The WHR was higher in the heavy drinking group than in the other groups(p<0.01), while the other anthropometric indices were not significantly different among the three groups. The calorie intake was highest(p<0.001) in the heavy drinking group(3,270.4$\pm$686.5 kcal), followed by moderate(2,602.8$\pm$415.8 kcal) drinking group and light drinking group(2,341.5$\pm$449.4 kcal). As alcohol consumption increased, there was a decrease in the percent of energy derived from carbohydrates and lipids, while there was an increase in the percent of energy derived from proteins and alcohol(p<0.001). The heavy and moderate drinking groups had a highers intake of protein compared to the light drinking group, and the heavy drinking group had a higher intake of lipid compared to the light and moderate drinking groups(p<0.01). The intakes of vitamin $B_2$, niacin and phosphorus were lower in the moderate group than the other groups(p<0.01). The average MAR(Mean adequacy ratio) was 1.44$\pm$0.35 and the intake of all nutrients, except for folic acid, was much higher than the Korean RI(Recommended intake). The fruit intake frequency and sleeping hours were the lowest in the heavy drinking group(p<0.05) and the subjects preferred the following order of food products when they drink: meat(42.5%), fish & shellfish(30.0%), fruit & vegetable(22.5%) and others(5.0%) as a side dish. The average rates of smoking and exercise for all the subjects were 77.5% and 67.5%, respectively. The results of this study showed that heavy alcohol drinkers were more prone to abdominal obesity and related chronic degenerative diseases, indicating the need for extensive nutritional education for heavy alcohol drinkers.