• Korean Journal of Food Science and Technology
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• v.8 no.4
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• pp.263-272
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• 1976

According to the intercombined review of chemical and biological investigation it has been noted that the metabolizable energy per gram dietary protein of mixed diet of daily intake patterned by Korean population has been found 3.4-3.6 Cal., which entails 10-12% level of the protein calorie percentage of total metabolizable energy, the biological value being fallen within the scope 63-73. The structure of dietary protein has revealed that the lysine and isoleucine were primary limiting amino acids and threonine secondary limiting as a general trend, however, it is assumed that the ultimate nutritional effect of dietary protein might be restricted uniformly among regions by the amount of lysine, since the lysine availability has been yielded as low as 72-82% level. As for the net protein utillization NPUst falls in the range of 52-62 and the NPUop 47-58. In either part the mountainous region has demonstrated lowest value and the urban area highest, these trend being obviously associated with the ratio of animal protein relative to the vegetable origin. The net dietary protein calorie percentage (NDpCal %) has been found within the range of 5-7 that may be capable of meeting the requirement for the maintenance of adult, though for the growth it is insufficient. Present level of total caloric intake would not influence on the fate of protein value of prevailing regional diet in terms of caloric restriction, since the present intake of food energy is higher than the lower limit of caloric intake that would impair the biological performance of dietary protein fed ad libitum basis. Based on the protein efficiency, the adequacy of current level of protein intake was analyzed in terms of utilizable protein, and it has been demonstrated that the 37.8g of utilizable protein in the fishery region and 38.2g in the mountainous region were bellow the FAO recommendation. Accordin to the hematological study it may be interpreted that the anemic symptoms of the mountainous region has some possibility of being related to the inferior status of dietary protein in quality as well as in quantity.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.8
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• pp.1297-1304
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• 2007

We conducted a series of investigations in order to elucidate role of nutritional status in regulating GLUT expression and energy metabolism in porcine muscle. Firstly, the role of mild undernutrition in regulating muscle GLUT gene expression and function was studied in growing pigs (3 wk of age) on a high (H) or low (L) food intake (H = 2L) at $35^{\circ}C$ or $26^{\circ}C$. Low food intake selectively upregulates GLUT1 and GLUT4 gene expression; mRNA levels were elevated in longissimus dorsi (L. dorsi) and rhomboideus muscles but not in diaphragm or cardiac muscles. Our next step was to determine whether dietary lysine, a major primary limiting amino acid in diets for pigs, affects muscle GLUT4 expression. Pigs of 6 wk of age were pair-fed a control or low lysine (LL) diet. The control diet contained optimal amounts of all essential amino acids, including 1.15% lysine. The LL diet was similar but contained only 0.70% lysine. GLUT4 mRNA expression was upregulated by the LL diet in L. dorsi and rhomboideus muscles, whereas that in cardiac muscle was unaffected. GLUT4 protein abundance was also higher in rhomboideus muscle of animals on the LL diet. We conducted another investigation in order to elucidate effects of the LL diet on post-GLUT4 glucose metabolism. Activity of hexokinase was unaffected by dietary lysine levels while that of citrate synthase was higher both in L. dorsi and rhomboideus muscles of pigs fed on the LL diet. Glucose 6-phosphate content was higher in L. dorsi msucle in the LL group. Glycogen content was higher both in L. dorsi and rhomboideus muscles in the LL group. Further, we determined the effects of dietary lysine levels on accumulation of intramuscular fat (IMF) in L. dorsi muscle of finishing pigs. A low lysine diet (lysine content was 0.40%) meeting approximately 70% of the requirement of lysine was given to finishing pigs for two months. IMF contents in L. dorsi of the pigs given the low lysine diet were twice higher than those of the pigs fed on a control diet (lysine content was 0.65%). Finally, we proved that a well known effect of breadcrumbs feeding to enhance IMF of finishing pigs could be attributed to shortage of amino acids in diets including breadcrumbs.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.6
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• pp.777-790
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• 2022

This study was conducted to investigate the nutritional characteristics of the following Korean-distributed fish species commonly consumed as sliced raw fish (CC-SRF): olive flounder Paralichthys olivaceus (OF), red sea bream Pagrus major (RS), Atlantic salmon (AS), coho salmon (CS) and sockeye salmon (SS). The crude protein and lipid contents of OF, RS, AS, CS and SS were 20.2% and 5.5%, 21.2% and 6.8%, 17.7% and 18.5%, 18.3% and 16.1%, and 20.4% and 5.7%, respectively. Regardless of the type and weight of fish species, the major amino acids were leucine, lysine, aspartic acid, and glutamic acid, whereas histidine was identified as a limiting amino acid. The major minerals in all CC-SRF were P, K and Se based on the recommended daily intake or sufficient intake for Korean males aged between 19-49 years. Among the different types of all CC-SRF, the intake of OF and SS lipids is predicted to be associated with a lower n-6/n-3 fatty acid ratio, whereas among the free amino acids, which are expected to have health functionality, we identified taurine in OF and RS, and anserine in salmons. The digestibility of OF, RS, AS, CS and SS were 60.7%, 54.9%, 48.5%, 49.6%, and 53.4%, respectively.

• Journal of Nutrition and Health
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• v.14 no.1
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• pp.16-25
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• 1981

Commercially available duck-meat was subjected to proximate analysis. On a wet basis, the duck-meat contained 62.87, 17.05, 19.06 ana 1.02 percent of moisture, crude fat, crude protein and ash, respectively. Almost all the essential amino acids contained in the duck-meat protein, ana the tryptophan was the limiting one by amino acid analysis of GLC. An analysis of the fatty acid composition by GLC showed a relatively high concentration of oleic acid. There was also a considerable content of linoleic acid. The content of polyunsaturated fatty acids of duck-meat was 70.9% and the P/S ratio of fatty acids was 3.4. The cholesterol content in duck-meat was determined to be approximately 70. 5mg/100g ofm sample. According to blood analysis, it was understood that the content of phospholipids was relatively high, particulary in lecithin. ATP-phosphorus, at the higher temperature, was released faster than at the lower temperature, by two hours after postmortem. The ATPase activity of Myogibril was inhibited at the relatively high concentration of added EDTA and metallic ions, but the activity was very high in the lower concentrations. According to the cooking conditions, boiled duck-meat showed good digestion by pepsin. It was understood that the digestibility of duck meat was relatively high, so the duck-meat protein is good source of animal protein. Therefore, it is able to be recommended that duck-meat is good nitrogen source animal food.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.3
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• pp.325-330
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• 1993

The objectives of the present study were to investigate whether or not dietary lysine addition could improve N balance of female Japanese Saanen goats at 15 to 32 months of age, weighing 31 to 40 kg, fed on a wheat bran-hay cube diet supplemented with methionine, and whether or not ruminally protected lysine supplementation could give as good an N balance performance as lysine in the presence of ruminally protected methionine when given orally to the goats. It was considered from changes in N balance and N utilization that the first-and second-limiting amino acids in the diet were methionine and lysine respectively, under the present experimental conditions. The ruminally protected lysine in addition to the ruminally protected methionine gave no improvement in N balance and N utilization compared with the ruminally protected methionine alone, suggesting that the ruminally protected lysine used in the present study was not effectively utilized by the goats.

• Nutritional Sciences
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• v.6 no.4
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• pp.189-194
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• 2003

Most of the ethyl alcohol consumed by humans is oxidized to acetaldehyde in the liver by the cytoplasmic alcohol dehydrogenase (ADH) system. For this ADH-catalyzed oxidation of alcohol, $NAD^+$ is required as the coenzyme and $NAD^+$becomes reduced to NADH. As the $NAD^+$becomes depleted and NADH accumulates, alcohol oxidation is reduced. For continued alcohol oxidation, the accumulated NADH must be quickly reoxidized to $NAD^+$, and it is this reoxidation of NADH to $NAD^+$that is known to be the rate-limiting step in the overall oxidation rate of alcohol The reoxidation of NADH to $NAD^+$is catalyzed by lactate dehydrogenase in the cytoplasm of hepatocytes, with pyruvate being utilized as the substrate. The pyruvate may be supplied from alanine as a result of amino acid metabolism via the urea cycle. Also, glutamine is thought to help with the supply of pyruvate indirectly, and to activate the urea cycle by producing $NH_3$. Thus, in the present study, we have examined the effects of alanine and glutamine on the alcohol oxidation rate. We utilized isolated perfused liver tissue in a system where media containing alanine and glutamine was circulated. Our results showed that when alanine (5.0mM) was added to the glucose-free infusion media, the alcohol oxidation rate was increased by 130%. Furthermore, when both glutamine and alanine were added together to the infusion media, the alcohol oxidation rate increased by as much as 190%, and the rate of urea nitrogen production increased by up to 200%. The addition of glutamine (5.0mM) alone to the infusion media did not accelerate the alcohol oxidation rate. The increases in the rates of alcohol oxidation and urea nitrogen production through the addition of alanine and glutamine indicate that these amino acids have contributed to the enhanced supply of pyruvate through the urea cycle. Based on these results, it is concluded that the dietary supplementation of alanine and glutamine could contribute to increased alcohol detoxification through the urea cycle, by enhancing the supply of pyruvate and $NAD^+$to ensure accelerated rates of alcohol oxidation.

• Molecules and Cells
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• v.28 no.6
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• pp.575-581
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• 2009

Ornithine decarboxylase (ODC) is a rate-limiting enzyme in the biosynthesis of polyamines, which are essential for cell growth, differentiation, and proliferation. This report presents the characterization of an ODC-encoding cDNA (SlitODC) isolated from a moth species, the tobacco cutworm, Spodoptera litura (Lepidoptera); its expression in a polyamine-deficient strain of yeast, S. cerevisiae; and the recovery in polyamine levels and proliferation rate with the introduction of the insect enzyme. SlitODC encodes 448 amino acid residues, 4 amino acids longer than B. mori ODC that has 71% identity, and has a longer C-terminus, consistent with B. mori ODC, than the reported dipteran enzymes. The null mutant yeast strain in the ODC gene, SPE1, showed remarkably depleted polyamine levels; in putrescine, spermidine, and spermine, the levels were > 7, > 1, and > 4%, respectively, of the levels in the wild-type strain. This consequently caused a significant arrest in cell proliferation of > 4% of the wild-type strain in polyamine-free media. The transformed strain, with the substituted SlitODC for the deleted endogenous ODC, grew and proliferated rapidly at even a higher rate than the wild-type strain. Furthermore, its polyamine content was significantly higher than even that in the wild-type strain as well as the spe1-null mutant, particularly with a very continuously enhanced putrescine level, reflecting no inhibition mechanism operating in the putrescine synthesis step by any corresponding insect ODC antizymes to SlitODC in this yeast system.

• Journal of the Korean Society of Tobacco Science
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• v.29 no.2
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• pp.140-145
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• 2007

Acrylamide has been found in many foods. Acrylamide in foodstuffs were analyzed by a GC/MS after bromination of acrylamide or by a LC/MS for underivatized acylamide. Time consuming and laborious clean up procedures is applied for the purification of the extract, in these methods. In this study, a simple and fast method without clean up step for the analysis of acrylamide in mainstream cigarette smoke was developed by using liquid chromatography-tandem mass spectrometry (LC/MS/MS) and the effects of tobacco leaf constituents on acrylamide content was observed. The analysis of acrylamide in mainstream cigarette smoke started to collect TPM (total particulate matter) from smoking and to extract by 0.1 % acetic acid solution and then to detect by liquid chromatography tandem mass spectrometry using electrospray in the positive mode. The recovery of acrylamide in 2R4F reference cigarette was 98 % and the reproducibility was 2.5 % and the limit of detection was 1.6 ng/mL. Reducing sugars and amino acids are considered to be main precursors of acrylamide in foodstuffs. Cut tobacco contain substantial amounts of reducing sugars and amino acid which may be explained the occurrence of acrylamide in mainstream cigarette smoke. The effects of reducing sugars and total nitrogen studied in an experiment with a various tobacco types. This result indicated that reducing sugars are not limiting factor for acrylamide formation, but the level of acrylamide in cigarette smoke was significantly correlated with the total nitrogen contents.

• Journal of Chest Surgery
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• v.42 no.4
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• pp.409-417
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• 2009

Background: Glutaraldehyde-fixed heterografts are prone to calcification after long-term implantation in human, and this is one of the limiting factors for the longevity of the heterografts used in cardiovascular surgery. The aim of the study was to evaluate the anticalcification effect of an ethanol and amino acids treatment on glutaraldehyde-fixed bovine pericardium. Material and Method: Bovine pericardial tissues were divided into 5 groups. Group 1 consisted of tissues fixed with glutaraldehyde, group 2 consisted of commercially available bovine pericardial valve tissues (Carpentier-Edwards PERIMOUNT), group 3 consisted of glutaraldehyde-fixed tissues treated with ethanol, group 4 consisted of glutaraldehyde-fixed tissues treated with ethanol and L-glutamic acid, and group 5 consisted of glutaraldehyde-fixed tissues treated with ethanol and homocysteic acid. The tissue microstructure was examined by light and electron microscopy. Tissue samples of each group were implanted into rat subcutaneous tissue for 3 $\sim$ 4 months and the calcium contents were measured after harvest. Result: The collagen fibers appeared to be well preserved in all the groups. The calcium contents of groups 2, 3, 4 and 5 (13.46$\pm$11.74, 0.33$\pm$0.02, 0.39$\pm$0.08 and 0.42$\pm$0.06 $\mu$g/mg, respectively) were all significantly lower than that of group 1 (149.97$\pm$28.25 $\mu$g/mg) (p<0.05). The calcium contents of groups 3, 4 and 5 were all significantly lower than that of group 2 (p<0.05). Conclusion: Treatment with ethanol alone or in combination with amino acids (L-glutamic acid or homocysteic acid) strongly prevented the calcification of glutaraldehyde-fixed bovine pericardium.

• Journal of the Korean Society for Marine Environment & Energy
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• v.16 no.1
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• pp.25-35
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• 2013

Dominance and survival strategy of toxic dinoflagellate Alexandrium tamarense and A. catenella under the dissolved inorganic nitrogen (DIN) limited conditions were examined in the laboratory and field observations. In Masan Bay, DIN was limiting factor for growth of phytoplankton during spring to early summer when Alexandrium spp. have been observed. They have a disadvantageous position compared with diatoms because Ks of nitrate calculated from growth kinetics experiment of A. tamarense and A. catenella was higher than diatoms. However, A. tamarense and A. catenella were able to grow using dissolved organic nitrogen (DON) compounds such as urea and amino acids as well as DIN. Therefore, DON utilization of A. tamarense, A. catenella might contribute to not only their population growth but also dominance and interspecific competition in the DIN-limited conditions in Masan Bay.