• Korean System Dynamics Review
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• v.6 no.1
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• pp.17-32
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• 2005

An agricultural commodity production cycle model consisting of corn, beef, and dairy sectors was constructed for the purpose of exploring the propagating effects of large-scale disruptive events. In an initial proof-of-concept exercise, we considered an agricultural disruption scenario in which foot-and-mouth disease (FMD) is introduced into the U.S., causing a large-scale outbreak of the disease in both beef and dairy cattle. The magnitude of disruption to the beef and dairy sectors are presented under the existing W response policy and then improvements under two alternative policies are shown.

• Food Science of Animal Resources
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• v.34 no.4
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• pp.482-495
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• 2014

The objectives of this study were to know the effect of repeated freeze-thaw cycles of beef on the sensory, physicochemical quality and microbiological assessment. The effects of three successive freeze-thaw cycles on beef forelimb were investigated comparing with unfrozen fresh beef for 75 d by keeping at $-20{\pm}1^{\circ}C$. The freeze-thaw cycles were subjected to three thawing methods and carried out to know the best one. As the number of freeze-thaw cycles increased color and odor declined significantly before cook within the cycles and tenderness, overall acceptability also declined among the cycles after cook by thawing methods. The thawing loss increased and dripping loss decreased significantly (p<0.05). Water holding capacity (WHC) increased (p<0.05) until two cycles and then decreased. Cooking loss increased in cycle 1 and 3, but decreased in cycle 2. pH decreased significantly (p<0.05) among the cycles. Moreover, drip loss, cooking loss and WHC were affected (p<0.05) by thawing methods within the cycles. 2-Thiobarbituric acid (TBARS) value increased (p<0.05) gradually within the cycles and among the cycles by thawing methods. Total viable bacteria, total coliform and total yeast-mould count decreased significantly (p<0.05) within and among the cycles in comparison to the initial count in repeated freeze-thaw cycles. As a result, repeated freeze-thaw cycles affected the sensory, physicochemical and microbiological quality of beef, causing the deterioration of beef quality, but improved the microbiological quality. Although repeated freeze-thaw cycles did not affect much on beef quality and safety but it may be concluded that repeated freeze and thaw should be minimized in terms of beef color for commercial value and WHC and tenderness/juiciness for eating quality.

• Journal of agriculture & life science
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• v.46 no.6
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• pp.197-205
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• 2012

This paper analyzes the beef cycle and forecasts the number of Hanwoo. This study uses Sine function for this purpose. Data shows that beef cycle varies from five to twelve years and the cycle becomes longer as time passes. The adjusted $R^2$ of the estimated model is 0.95. The forecasted value based on this model for the number of Hanwoo is 1.6-1.8 million heads in lower bound and 3.2-3.7 million heads in upper bound, where the peak points are slightly different according to cycles. These predicted values imply the instability of number of Hanwoo and corresponding farm income, so we have to prepare adequate policies to cope with it.

• Food Science of Animal Resources
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• v.35 no.6
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• pp.772-782
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• 2015

This study was performed to explore the deterioration of physicochemical quality of beef hind limb during frozen storage at −20℃, affected by repeated freeze-thaw cycles. The effects of three successive freeze-thaw cycles on beef hind limb were investigated comparing with unfrozen beef muscle for 80 d by keeping at −20±1℃. The freeze-thaw cycles were subjected to three thawing methods and carried out to select the best one on the basis of deterioration of physicochemical properties of beef. As the number of repeated freeze-thaw cycles increased, drip loss decreased and water holding capacity (WHC) increased (p<0.05) till two cycles and then decreased. Cooking loss increased in cycle one and three but decreased in cycle two. Moreover, drip loss, WHC and cooking loss affected (p<0.05) by thawing methods within the cycles. However, pH value decreased (p<0.05), but peroxide value (p<0.05), free fatty acids value (p<0.05) and TBARS value increased (p<0.05) significantly as the number of repeated freeze-thaw cycles increased. Moreover, significant (p<0.05) interactive effects were found among the thawing methods and repeated cycles. As a result, freeze-thaw cycles affected the physicochemical quality of beef muscle, causing the degradation of its quality.

• Korean Journal of Human Ecology
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• v.14 no.1
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• pp.217-221
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• 2005

In this study, the effect of microwave treatment on physico-chemical properties and microbial changes of beef and pork loin was investigated. Beef and pork were heated in microwave with an adjusted electric output at 500 W and operating frequency 2,450 MHz. The beef and pork samples were treated with microwave for 10 s or 20 s at 50% duty cycle. Drip losses and TBA values of beef and pork samples increased due to the microwave treatment. The samples became darker and more yellowish through microwaves, whereas their redness was unchanged. Microbial content of beef and pork samples declined as the treatment time increased. When pork samples were heated in a microwave oven, organisms were reduced by 2 log cycles in 20 s. It was concluded that a 20 second-long microwave treatment can great1y enhance the microbial safety of the pork sample.

• Korean Journal of Animal Reproduction
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• v.12 no.2
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• pp.91-96
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• 1988

A study was conducted to improve breeding efficiency of dairy and beef cows on Cheju Island. Milk progesterone and plasma progesterone profiles were determined by using radioimmunoassay techniques during the oestrus cycle, onset on oestrus and during the gestation period. Progesterone connections in milk were very low during the oestrus with a means value of 2.4ng/ml and 4.6ng/ml at the onset of oestrus but gradually declined at 4 to 9 hr after oestrus. In the cyclic cow, milk progesterone concentraitons in the early part of the cycle, ranged from 3 to 5ng/ml and increased from 6.0 to 11.6ng/ml on day 13 to 21 of cycle. Milk progesterone concentrations of pregnancy cows ranged from 5.0 to 40ng/ml during the gestation and grom basal line to 3.5ng/ml for nonpregnant cows. Plasma progesterone concentrations of beef during pregnancy period ranged form 3.0 to 33ng/ml and basal levels ranged from 0 to less than 2.5ng/ml for non-pregnant beef cows.

• Korean Journal of Organic Agriculture
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• v.17 no.4
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• pp.463-481
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• 2009

Regional Agricultural Cluster(RAC) at Asan area has been formed with Purundeul farming union corporation(Purundeul) as the center from the year 2005. Originally, RAC has been proceeded by Ministry for Food, Agriculture, Forestry and Fisheries (MFAFF) all over the nation from 2005. This RAC has helped Asan area to establish the foundation of environmentally friendly agriculture(EFA) searching for nutritional cycle. This also made jumping age turn developing age in EFA at Asan area. The number of Purundeul producer members was 386 farmers in 2008. Purundeul introduced organic livestock farming(Korean beef cattle; Hanwoo) for proceeding EFA searching for nutritional cycle in 2007, and had 719 cattle at the end of March 2009. Feedstuff materials for organic livestock is mostly produced from seeding farming by-products within Asan or the country. Asan RAC had built factories for feedstuff producing and beef processing with producers' investment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.6
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• pp.1016-1024
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• 2000

The study was conducted to develop a rapid method for the detection of Listeria monocytogenes in foods via polymerase chain reaction (PCR) technique using hemolysin gene (hlyA) primers. Specificity and sensitivity of PCR, optimal conditions for PCR and application of hlyA gene primers for the detection of L. monocytogenes from milk and beef were investigeted. Each of the 20 L. monocytogenes strains gave a single 713 bp band, but other Listeria sup. and other bacteria did not show any bands. As few as 1 pg of L. monocytogenes DNA or 2.4$\times$10$^4$L. monocytogenes cells could be detected with hlyA gene primers. PCR product was most improved at 20~30 cycle in terms of removal of tailing and sensitivity. Also, the sensitivity was significantly improved by the further 10~15 cycle after 20 cycle PCR amplication. Milk (10 mL) and beef (10 g) samples were inoculated with L. monocytogenes at the concentrations ranging from 0 to 10$^{7}$ CFU/mL or g to determine the best sensitivity of PCR for the rapid detection of L. monocytogenes. PCR assay could detect 2 cells in milk with repeating PCR amplication and 2.6$\times$10$^2$cells in beef sample after 24 hr enrichment growth at 35$^{\circ}C$ in LEB.

• Korean System Dynamics Review
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• v.14 no.3
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• pp.135-163
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• 2013

This study aims to analyze the feedback loops and policy simulation of price fluctuation of Korean Cattle. The Korean Cattle market shows the 'Cycle of Beef' since 1970. In general, the market for agricultural commodities exhibit repeated cycles of prices and production. Why Beef products market in Korea shows the fluctuation of cattle and beef price repeatedly for forty years? To find an answer, this paper explores the feedback structure of the dynamics of the beef market by the systems thinking and build a stock-flow diagram model for the simulation of future behavior of the market sector of the Cattle. The dynamic simulation model was developed to identify and analyze the cyclical behavior among many variables, which is the number of cattle (calves, cow, etc.), the price of cattle, the demand for beef, the desirable number of cattle, slaughter, etc. The results of this study demonstrate that dominant feedback loops between the number of cattle and livestock prices. The demand for Beef and slaughter with time delay, also the results of the simulation to explain the persistence of future price fluctuations and actions meat market until 2025.

• Animal Bioscience
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• v.36 no.3
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• pp.506-520
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• 2023

Objective: Japanese Brown (JBR) cattle, especially the Kochi (Tosa) pedigree (JBRT), is a local breed of moderately marbled beef. Despite the increasing demand, the interbreed differences in muscle metabolites from the highly marbled Japanese Black (JBL) beef remain poorly understood. We aimed to determine flavor-related metabolites and postmortem metabolisms characteristic to JBRT beef in comparison with JBL beef. Methods: Lean portions of the longissimus thoracis (loin) muscle from four JBRT cattle were collected at 0, 1, and 14 d postmortem. The muscle metabolomic profiles were analyzed using capillary electrophoresis time-of-flight mass spectrometry. The difference in post-mortem metabolisms and aged muscle metabolites were analyzed by statistical and bioinformatic analyses between JBRT (n = 12) and JBL cattle (n = 6). Results: A total of 240 metabolite annotations were obtained from the detected signals of the JBRT muscle samples. Principal component analysis separated the beef samples into three different aging point groups. According to metabolite set enrichment analysis, post-mortem metabolic changes were associated with the metabolism of pyrimidine, nicotinate and nicotinamide, purine, pyruvate, thiamine, amino sugar, and fatty acid; citric acid cycle; and pentose phosphate pathway as well as various amino acids and mitochondrial fatty acid metabolism. The aged JBRT beef showed higher ultimate pH and lower lactate content than aged JBL beef, suggesting the lower glycolytic activity in postmortem JBRT muscle. JBRT beef was distinguished from JBL beef by significantly different compounds, including choline, amino acids, uridine monophosphate, inosine 5'-monophosphate, fructose 1,6-diphosphate, and betaine, suggesting interbreed differences in the accumulation of nucleotide monophosphate, glutathione metabolism, and phospholipid metabolism. Conclusion: Glycolysis, purine metabolism, fatty acid catabolism, and protein degradation were the most common pathways in beef during postmortem aging. The differentially expressed metabolites and the relevant metabolisms in JBRT beef may contribute to the development of a characteristic flavor.