• 한국축산식품학회지
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• 제42권3호
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• pp.398-410
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• 2022

We studied effects of aging methods and temperature on the physical, chemical, and amino acid composition of pork belly from Berkshire and Landrace×Yorkshire×Duroc (LYD) swine. Pork belly samples were assigned randomly to breed groups (Berkshire and LYD), aging temperature groups (0℃ and 9℃), and aging method groups. One samples of vacuum-packaged hanging pork bellies were hung in a refrigerated cooler with 83±2.0% humidity, while the other samples were immersed in a 3.5% salt solution in a vacuum package and subsequently stored in the same cooler for 2 weeks. LYD pork had lower pH and purge loss and higher lightness values than those of Berkshire pork (p<0.05). Moreover, thiobarbituric acid reactive substances and hardness values of LYD pork were lower than those of Berkshire pork after aging (p<0.05). Berkshire pork had a higher level of flavorful amino acids than LYD pork did during aging (p<0.05). Bellies aged at elevated temperatures for two weeks had higher volatile basic nitrogen. However, significantly higher percentages of flavorful and sweet taste amino acids were observed in bellies aged at 9℃ compared to those aged at 0℃ for 2 weeks. Moisture content was higher in immersed samples than hanging samples after two weeks of aging (p<0.05). Hanging pork bellies exhibited higher texture profiles than immersed pork bellies at two weeks (p<0.05). We concluded that breeds, aging temperature, and methods affected most quality attributes of pork belly.

• 한국축산식품학회지
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• 제38권3호
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• pp.515-529
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• 2018

The present study was designed to investigate the effects of calpain system on the formation of volatile flavor compounds in Hanwoo beef. In the first experiment (exp.1), Longissimus lumborum (LL) muscle samples were injected with solutions containing 50 mM $CaCl_2$ or 50 mM $ZnCl_2$ and 154 mM NaCl respectively, and aged for 7 d at $4^{\circ}C$. In the second experiment (exp.2), the ground LL muscle was incubated with the aforementioned solutions containing cathepsin inhibitor. The injection with $CaCl_2$ solution greatly elevated the calpain activity and concomitantly, significantly decreased the Warner-Bratzler shear force (p<0.05). The pH, meat color and cooking loss did not differ (p>0.05) between the treatment groups. A total of 51 volatile compounds were identified using the solid phase microextraction with gas chromatography (SPME-GC). Results on volatile analyses from the both experiments showed that the injection with calcium ions led to significant increase (p<0.05) concentrations of pyrazines and sulfuric compounds. These results coincide with a higher rate of protein degradation due to the $CaCl_2$ injection as compared to the control group. Significantly (p<0.05) higher levels of lipid oxidation derived-aldehydes were found in the samples with $ZnCl_2$. The exp.1 showed that cathepsin inhibitors had no effect on the formation of volatile flavor components after 7 d of aging. These results imply that the proteolytic activity of the calpain system is associated with generation of volatile compounds of chiller-aged beef, while the role of cathepsins is likely very limited.

• 한국축산식품학회지
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• 제36권2호
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• pp.215-222
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• 2016

The combined effects of irradiation and aging temperature on the microbial and chemical quality of beef loin were investigated. The samples were vacuum-packaged, irradiated at 0 or 2 kGy using electron-beam (EB), and stored for 10 d at different aging temperatures (2, 14, or 25℃). The microbial growth, shear values, meat color, and nucleotide-related flavor compounds of the samples were analyzed. The irradiation effect on inactivation of foodborne pathogens was also investigated. The population of Listeria monocytogenes and Escherhia coli O157:H7 inoculated in beef samples decreased in proportion to the irradiation dose. Irradiation reduced the total aerobic bacteria (TAB) over the storage, but higher aging temperature increased the TBA. Thus TAB increased sharply in non-irradiated and high temperature-aged (14, 25℃) beef samples after 5 d. With increasing aging temperature and aging time, shear force values decreased. Lipid oxidation could be reduced by short aging time at low aging temperature. The color a* values of the irradiated beef were lower than those of the non-irradiated throughout the aging period. As aging period and temperature increased, IMP decreased and hypoxanthine increased. Considering microbial and physicochemical properties, irradiation can be used for raw beef to be aged at relatively high temperature to shorten aging time and cost.

• Asian-Australasian Journal of Animal Sciences
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• 제32권8호
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• pp.1172-1185
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• 2019

Objective: Meat quality attributes in postmortem muscle tissues depend on skeletal muscle metabolites. The objective of this study was to determine the key metabolic compounds and pathways that are associated with postmortem aging and beef quality in Japanese Black cattle (JB; a Japanese Wagyu breed with highly marbled beef). Methods: Lean portions of Longissimus thoracis (LT: loin) muscle in 3 JB steers were collected at 0, 1, and 14 days after slaughter. The metabolomic profiles of the samples were analyzed by capillary electrophoresis time-of-flight mass spectrometry, followed by statistical and multivariate analyses with bioinformatics resources. Results: Among the total 171 annotated compounds, the contents of gluconic acid, gluconolactone, spermidine, and the nutritionally vital substances (choline, thiamine, and nicotinamide) were elevated through the course of postmortem aging. The contents of glycolytic compounds increased along with the generation of lactic acid as the beef aging progressed. Moreover, the contents of several dipeptides and 16 amino acids, including glutamate and aromatic and branched-chain amino acids, were elevated over time, suggesting postmortem protein degradation in the muscle. Adenosine triphosphate degradation also progressed, resulting in the generation of inosine, xanthine, and hypoxanthine via the temporal increase in inosine 5'-monophosphate. Cysteine-glutathione disulfide, thiamine, and choline increased over time during the postmortem muscle aging. In the Kyoto encyclopedia of genes and genomes database, a bioinformatics resource, the postmortem metabolomic changes in LT muscle were characterized as pathways mainly related to protein digestion, glycolysis, citric acid cycle, pyruvate metabolism, pentose phosphate metabolism, nicotinamide metabolism, glycerophospholipid metabolism, purine metabolism, and glutathione metabolism. Conclusion: The compounds accumulating in aged beef were shown to be nutritionally vital substances and flavor components, as well as potential useful biomarkers of aging. The present metabolomic data during postmortem aging contribute to further understanding of the beef quality of JB and other breeds.

• 한국축산식품학회지
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• 제43권3호
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• pp.512-530
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• 2023

The present study evaluated the effects of fermented whey protein using kimchi lactic acid bacteria Lactobacillus casei DK211 on skeletal muscle mass, muscle strength, and physical performance in healthy middle-aged males performing regular resistance exercises. Effective protein supplementation and regular exercise are two important factors for improving muscle health. Therefore, in this study, the effects of consuming fermented whey protein twice a day were investigated and compared with that of non-fermented supplementation. Forty-eight males (average age 44.8) were randomly assigned to two groups: Fermented whey protein supplementation (FWPS) and non-fermented whey protein concentration supplementation (WPCS) groups. Each group ingested 37 g of FWPS or WPCS twice a day for eight weeks. Body composition, muscle strength, and physical performance were assessed pre- and post-intervention. Independent t-tests or chi-square tests for the categorical variables were performed for analyzing the observations. FWPS was effective in promoting the physical performance in dynamic balance measurement and muscle health, indicated through the increment in grip strength (left), upper arm circumference, and flat leg circumference from the baseline. However, similar improvements were not observed in the WPCS group. These results imply that whey protein fermented by L. casei DK211 is an effective protein supplement for enhancing muscle health in males performing regular resistance exercises.

• 한국가금학회지
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• 제33권1호
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• pp.15-24
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• 2006

본 연구는 종계사료 내 홍화씨 및 키토산의 첨가 급여가 산란종계에서 종란 생산성 및 후기 난각질 강화에 미치는 영향을 검토하기 위하여 수행하였다. 54주령 Hy-Line Brown 산란종계 암탉 400수와 수탉 40수를 공시하여 Ca을 3.5%로 수준으로 함유한 실험사료(대조구)에 홍화씨 분말을 0.25% 및 0.50% 수준으로 첨가하거나 키토산을 0.10% 및 0.20% 수준으로 첨가한 총 5개의 실험사료(4반복)를 6주간 급여하였다. 사료섭취량 및 난생산성에서는 처리간에 차이가 없었으나, 종란율은 대조구에 비해 홍화씨 분말 및 키토산을 첨가한 모든 실험구에서 첨가 수준과 관계없이 유의하게 증가하였다(P<0.05). 평균 난각 강도는 홍화씨 분말 및 키토산 첨가에 의해 유의하게 개선되었으며(P<0.01), 난각 두께는 키토산 첨가구가 대조구에 비해 유의하게 높은 것으로 나타났다(P<0.01). 수정율 및 입란대 부화율은 대조구에 비해 키토산 첨가구에서 유의하게 개선되는 결과가 관찰되었다. (P<0.01). 경골 파쇄강도는 처리간에 큰 차이가 없었으나, 경골 내 Ca 및 P 함량은 대조구에 비해 홍화씨 분말 0.5% 첨가구와 키토산 첨가구(T3 및 T4)에서 유의하게 증가하였다. (P<0.01). 혈중 estrogen, calcitonin 및 PTH 등 호르몬 농도에서는 큰 변화가 없는 것으로 나타났다. 상기의 결과로부터 산란종계의 후기 난각질 및 생산성의 개선을 위해서는 사료 내 홍화씨 및 키토산과 같은 Ca의 이용성에 영향을 미치는 성분을 적절히 활용함으로써 후기 난각질과 부화율의 개선을 통해 종란 생산성을 향상시킬 수 있을 것으로 사료된다.

• 동의생리병리학회지
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• 제18권6호
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• pp.1580-1584
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• 2004

On the basis of the widely collected fork prescriptions, long clinical practice of himself, together with integration of all the good points of earlier medical specialists, 孫思邈 wrote 『千金方』 of thirty volumes. Among them Volumes 『食治』 (Food Therapy) and 『養性』(Cultivating the Character) are especially meaningful for in gerontology. Thirty years after its completion, as a supplement, he wrote another thirty volumes of 『千金翼方』. Mr. Sun integrated his discoveries in the treatments of the aged patients, and his opinions for longevity into the Volumes 『養性』 (Cultivating the Character), 『?穀』(Fasting), 『退居』(Retirement), 『補益』(Supplementation). Thus he laid down the basic foundation for the gerontology of Chinese medicine. 『千金要方』 and 『千金翼方』 by Mr. Sun discuss mainly the prevention of illness for aged patients. As for the function of food therapy, he explains: 'Food can dispel evil elements of the body and settle down its organs. It can further bring pleasure to man's spirit and help the circulation of blood and breath.' He then propose the major method of food therapy: 'For a medical doctor, he should understand the causes of disease, then treat it with food. Only after the food treatment fails, medicine is employed.' He thinks that medicine does work in treatment, but it also creates imbalance in the body, and makes the latter vulnerable to outside harms. Therefore, a good doctor is the one who cures the disease and bring pleasure to the patient with food. He stresses that food therapy is always a priority. Mr. Sun prefers animal's organs in the food therapy for aged. For example, he uses powder of sheep's kidney to treat the lumbago. He suggests the viewpoint of 'Curing man's organs with animal's organs' and 'Strengthening man's organs with animal's organs,' and sets the theoretical foundation of 'Organic Treatment.' Mr. Sun's gerontology and food therapy received further development latter. The prescriptions contained therein had been widely used in 王懷隱's 『太平聖惠方』 and 陳直's 『養老奉親書』, both in the Song Dynasty. Eventually they had become a science of food therapy for aged patients.

• Asian-Australasian Journal of Animal Sciences
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• 제14권9호
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• pp.1209-1215
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• 2001

We conducted this study to investigate 24 h leptin profiles and to ascertain whether leptin secretion occurs in a pulsatile manner in cattle. Plasma leptin concentrations were measured every 10 min for 24 h in five Holstein steers aged 10 months. Simultaneously, feeding behavior was recorded every 5 min during this experiment. In two of the five cattle, leptin showed diurnal rhythmicity, which could be described by a cosine, with peaks between 15:00 and 16:00 and nadirs at around midnight. Pulsatile leptin release was quantified by model-free Cluster analysis. Plasma leptin showed a pulsatile pattern in all cattle, with an average number of pulses at 15 peaks/24 h. The daily number of pulses was not related to total time spent eating, ruminating or chewing. However, when divided into six 4 h time intervals, time spent ruminating was positively related with pulse number (p=0.05) in cattle showing no diurnal plasma leptin variation. These results suggest that cattle may have unique diurnal variation and pulsatile patterns of plasma leptin, differing from those of monogastric animals.

• 한국식생활문화학회지
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• 제22권6호
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• pp.833-840
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• 2007

The purpose of this study was to obtain baseline data of nutritional management for women's bone health according to age. This study was conducted through questionnaire, bone mineral density(BMD) measurement by DEXA and dietary survey by 24hr recalls to 134 adult women. Subjects were divided into three groups: young women group who aged 20-29(n=48), middle aged women group who aged over 30 and were pre-menopause(n=36), postmenopausal women group(n=48). The body fat percent of postmenopausal women group was the highest among the three groups. BMD of lumbar spine(L1-L2) were $0.93\;g/cm^2$ for young women, $0.97\;g/cm^2$ for middle aged women, and $0.88\;g/cm^2$ for postmenopausal women, respectively(p<0.05). BMD of femoral neck(p<0.05), trochanter(p<0.05), and ward's (p<0.001) were significantly decreased as age increasement. Drinking alcohol and skipping meals were significantly higher in young women groups than in the other groups, however frequency of doing regular exercise was significantly lower in young women groups. Young women group consumed the significantly higher amount of cereals(p<0.05), sugar and sweeteners(p<0.001), meats(p<0.01), eggs(p<0.01), milks(p<0.05) and oils(p<0.001) than middle aged and postmenopausal women. Also, energy(p<0.001), animal protein, (p<0.01), plant oil(p<0.001), animal fat(p<0.001), retinol(p<0.001), vitamin E(p<0.01), and cholesterol(p<0.001) intakes of young women were highest among the three groups. However, young women group consumed the significantly lower amount of dietary fiber(p<0.05), vitamin C(p<0.01), folate(p<0.05) and fruits(p<0.01) than the other groups. To summarized the our results, young women who were in still undergoing bone formation activity to develope peak bone mass, had more dietary habit and lifestyle problems than middle aged and postmenopausal women. The results of this study revealed that nutritional management and education for bone health should be emphasized in young women not only aged women.

• Nutritional Sciences
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• 제7권2호
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• pp.98-106
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• 2004

The dietary vitamin $B_6$ intake of 185 Korean children aged 7-12 years (y), who showed no health problems, in the Seoul area and its sources were estimated using a modified Korean vitamin $B_6$ database. The age and sex of each subject was classified according to the classifications in the Korean Recommended Dietary Allowance (RDA). Dietary vitamin $B_6$ intake and food sources were estimated using the three-day recall method with the help of a trained interviewer. Food portion sizes were estimated by using standard household measures and published average portion sizes. The average daily vitamin $B_6$ intake was 1.69$\pm$0.50 mg/d in children aged 7-9 y, 1.86$\pm$0.44 mg/d in male children aged 10-12 y and 1.77$\pm$0.62 mg/d in female children aged 10-12 y. Less than 5% of the subjects consumed less than the Korean RDA of vitamin $B_6$. The average ratio of vitamin $B_6$intake to daily protein intake was 0.028$\pm$0.006 mg/g in children aged 7-9 y, 0.028$\pm$0.004 mg/g in male children aged 10-12 y and 0.029$\pm$0.007 mg/g in female children aged 10-12 y. The intake of vitamin $B_6$ was significantly (p<.01) positively correlated to the intake of all other nutrients. Foods from animal and plant sources provided 37% and 73% respectively, of total vitamin $B_6$. Major dietary sources of vitamin $B_6$ in children in the Seoul area were rice, soybean sprouts, pork, beef, cereal, kimchi, milk, onions, and potatoes. As for major dietary sources of vitamin $B_6$, the top 20 foods provided nearly 73-75% of the total vitamin $B_6$ consumed by Korean children.