• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.3
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• pp.260-267
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• 2001

The biochemical composition and antioxidative activity of marine microalgae were investigated for the effective utilization of marine resources. Two species of marine microalgae, Nannochloris oculata (N. oculata) of Chlorophyceae and Phaeodactylum tricornutum (P. tricornutum) of Bacillariophyceae, were selected. Because these species showed the high growth rate and easy to continuous culture. The contents of crude protein, lipid, and carbohydrate were $54.91\%,\;11.29\%,\;and\;10.15\%$, for N. oculata and $38.07\%,\;13.19\%,\;and\;7.13\%$, for P. tricornutum, respectively. Glutamic acid was the highest concentration for both species. Galactose (3,712.02 mg/100g), fucose (1,966.03 mg/100g), and glucose (1,814.35 mg/100g) were the major carbohydrates for N. oculatae, and glucose (5,295.45 mg/100g) and mannose (841.34 mg/100g) were for P. tricornutum. K (12,906.86 mg/100g), Mg (1,039.15 mg/100g), Ca (882.57 mg/100g) and Fe (747.20 mg/100g) were the major minerals for N. oculata, and K (11,718.65 mg/100g), Ca (2,003.32 mg/100g), Mg (1,570.84 mg/100g) and Fe (552.58 mg/100g) were for P. tricornutum. In the composition of nucleotides, ADP ($4.77{\mu}mol/g$) was the highest in N. oculata and hypoxanthine (11.74{\mu}mol/g) in P. tricornutum. Large amount of linoleic acid (18: 2, $\omega-6$) was contained in N. oculata. In contrast 16: 1 ($\omega-7$) and 20: 5 ($\omega-3$) were major fatty acid in P. tricornutum. The antioxidative activities of organic solvent extracts of two microalgae were measured by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay method. The chloroform extract obtained from P. tricornutum was identified to be the most effective in DPPH radical scavenging activity.

• Journal of Life Science
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• v.23 no.8
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• pp.1004-1009
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• 2013

The biochemical compositions and nutritive values of six species of seaweeds were analyzed to determine their applicability in functional foods or ingredients. The biochemical compositions (moisture, ash, protein, lipid, and dietary fiber) and fatty acid contents were determined for the following seaweed extracts: Phaeophyceae (Laminaria japonica, Hizikia fusiformis, and Undaria pinnatifida), Rhodophyceae (Porphyra tenera and Gracilaria verrucosa), and Chlorophyceae (Ulva lactuca). The moisture content (% dry weight) ranged from 11.47% to 13.94%, ash from 19.15% to 26.50%, protein from 5.08% to 15.44%, lipid from 2.75% to 4.43%, and dietary fiber from 36.84% to 52.98%. C14:0, C16:0, C18:0, C16:1, C18: 1n-3, C18:2n-6, C18:3n-6, C20:4n-6, and C20:5n-3 represented the predominant proportions of fatty acids. Interestingly, docosahexaenoic acid (C22:6n-3, DHA) was either not found or only detected in trace amounts in the analyzed seaweeds. The levels of n-3 fatty acid were higher than other polyunsaturated fatty acids, and the n-6/n-3 ratio was very low. These results indicate that seaweed inhabiting Korean coastal areas will be beneficial to human health.

• Korean Journal of Food Science and Technology
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• v.17 no.1
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• pp.1-4
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• 1985

For the systematic investigation of biochemical characteristics of Korean ginseng protein by years, protein fractions were analyzed by the techniques of polyacrylamide gel electrophoresis, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and gel filtration, while the amino acid composition was studied by amino acid autoanalyzer. Results of polyacrylamide gel electrophoresis and SDS-PAGE showed a few difference in pattern and number of bands depending on the age of the root. However, the number of bands obtained from polyacrylamide gel electrophoresis and SDS-PAGE was 8 and 7 to 11, respectively. When water extracted proteins were fractionated by Sephadex G-200, the main peak among 2 peaks was collected and lyophillized. Its mol. wt. was extimated to be 43,000 by the SDS-PAGE method. In amino acid composition of water extracted protein and main fraction of gel filtration, arginine content was the highest, 47.17% in water extracted protein and 57.36% in main fraction followed by glutamic acid and asparatic acid. On the contrary, cystine and methionine contents were very low in both cases.

• Nutritional Sciences
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• v.6 no.1
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• pp.42-47
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• 2003

The objective of this study was to examine how circulating leptin concentrations and resting energy expenditures (REE) are related to body composition in obese adults, and to examine differences in these parameters according to gender. Twenty-three subjects, 6 males and 17 females, were recruited from patients with a body mass index (BMI) of greater than 27 at the Obesity Clinic of the K University Hospital. Anthropometric assessments and biochemical analyses were performed, and REEs were measured. In spite of having similar BMI values the plasma leptin levels of females (20.0$\pm$6.5 ng/ml) were significantly higher (p<.05) than those of males (14.2$\pm$6.1) ng/ml). In females, plasma leptin concentrations were found to be positively related to body weight. BMI, waist-hip ratio (WHR), fat mass (FM), body fat, and to the circumferences of forearm, waist and hip (p<.0001). However, in males, plasma leptin concentrations were positively related only to suprailiac thickness (p<.05). The higher plasma leptin levels in females compared to males may, at least partially. be explained by the females' higher subcutaneous fat mass. Plasma leptin concentrations appeared to reflect not only total fat mass but also regional fat distribution, especially in females. REE values of males (2254.3$\pm$256.2 kcal/day) were significantly higher (p＜.01) than those of females (1799.1$\pm$454.7 kcal/day). REE values for females were positively related to body weight, BMI, lean body mass (LBM), FM, body fat, and to the circumferences of waist and hip (p<.05); however, REE values for males were (positively) related only to LBM (p<.05). REE values were not related to plasma leptin concentrations for either males or females, indicating that the plasma level of leptin might not be a predictor for REE value.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.910-919
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• 2012

The role of inorganic nitrogen assimilation in the production of amino acids, organic acids and soluble sugars is one of the most important biochemical processes in plants, and, in order to achieve normally, nitrate uptake and assimilation is essential. For this reason, the characterization of nitrate assimilation and metabolite composition from leaves, roots and xylem sap of tomato (Solanum lycopersicum) was investigated under different nitrate levels in media. Tomato plants were grown hydroponically in liquid culture under five different nitrate regimes: deficient (0.25 and 0.75 mM $NO_3{^-}$), normal (2.5 mM $NO_3{^-}$) and excessive (5.0 and 10.0 mM $NO_3{^-}$). All samples, leaves, roots and xylem sap, were collected after 7 and 14 days after treatment. The levels of amino acids, soluble sugars and organic acids were significantly decreased by N-deficiency whereas, interestingly, they remained higher in xylem sap as compared with N-normal and -surplus. The N-excessive condition did not exert any significant changes in metabolites composition, and thus their levels were similar with N-normal. The gene expression and enzyme activity of nitrate reductase (NR), nitrite reductase (NIR) and glutamine synthetase (GS) were greatly influenced by nitrate. The data presented here suggest that metabolites, as a signal messenger, existed in xylem sap seem to play a crucial role to acquire nitrate, and, in addition, an increase in ${\alpha}$-ketoglutarate pathway-derived amino acids under N-deficiency may help to better understand plant C/N metabolism.

• Nutrition Research and Practice
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• v.13 no.6
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• pp.488-497
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• 2019

BACKGROUND/OBJECTIVES: There are various factors that affect metabolic abnormalities related to obesity. The purpose of this study is to analyze the differences in dietary intakes and body compositions of obese women according to metabolic risks and to classify them as metabolically healthy obese (MHO) or metabolically abnormal obese (MAO). SUBJECTS/METHODS: This study was conducted on 59 obese Korean women aged 19 to 60 years. NCEP-ATPIII criteria were applied and the women classified as MHO (n = 45) or MAO (n = 14). Body composition of each subject was measured by using dual-energy x-ray absorptiometry (DEXA). Three-day food records were used to analyze dietary intake. Eating habits and health-related behaviors were determined through questionnaires. Indirect calorimetry was used to measure resting metabolic rate and respiratory rate. RESULTS: The average age of the subjects was 43.7 years. The analysis of body composition according to phenotype revealed significantly higher body fat mass (P < 0.05), arm fat mass (P < 0.05), and android fat mass (P < 0.05), as measured by DEXA, in the MAO group than in the MHO group. There was no significant difference in the dietary intake of the two groups. However, eating behaviors differed. Compared to the MHO group, the MAO women had a shorter meal time (less than 10 minutes), a preference of oily foods, and a tendency to eat until full. Therefore, the eating habits of MHO women were more positive than those of MAO women. CONCLUSIONS: The results suggest that fat distribution in each body region affects various metabolic abnormalities. A high level of arm fat mass in obese Korean women may increase metabolic risk. In addition, eating habits of obese Korean women are considered to be environmental factors affecting the metabolic phenotype of obese Korean women.

• Journal of the Korean Society of Food Culture
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• v.25 no.1
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• pp.91-99
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• 2010

To elucidate the effects of an obesity control program on body composition and serum lipid levels, 31 obese elementary students (male: 25, female: 6) residing in the Gyeonggi area were evaluated and their body composition, serum total cholesterol, HDL-cholesterol, LDL-cholesterol and TG (triglyceride) were analyzed. The average age, height, weight and BMI (body mass index) were $11.52{\pm}1.00\;yrs$, $151.96{\pm}8.04\;cm$, $68.21{\pm}9.03\;kg$ and $29.40{\pm}1.79\;kg/m^2$ for the males, respectively, and $11.17{\pm}1.17\;yrs$, $147.83{\pm}5.15\;cm$, $65.05{\pm}10.86\;kg$ and $29.62{\pm}3.24\;kg/m^2$ for the females, respectively. There was a significant decrease in BMI for males (p<0.001) and females (p<0.05). There were also significant changes in all of the biochemical levels evaluated before and after the study. Specifically, the total cholesterol, LDL-cholesterol and TG level decreased after the obesity control program, while the HDL-cholesterol level increased after the program. These results indicate that obesity control programs do change the BMI, serum total cholesterol, HDL-cholesterol, LDL-cholesterol and TG levels in obese elementary students. Thus, obesity control programs are urgently needed to prevent degenerative disease and decrease obesity among children in elementary school.

• Clinical and Experimental Pediatrics
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• v.50 no.7
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• pp.629-635
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• 2007

Purpose : This study was conducted to assess the usefulness of fat-free mass index (FFMI) and fat mass index (FMI) as novel expression methods of body composition in children. Methods : A total of 466 Second grade students-248 boys and 218 girls- from all elementary schools the Gwacheon City underwent anthropometric measures including bioelectrical impedance analysis (BIA) and biochemical tests. The correlation coefficients between obesity indices, including FMI and FFMI, and metabolic risk factors, were assessed. Metabolic risk factors of children with increased FMI were compared with those of children with normal FMI. We compared FMI and FFMI percentile distribution between this study's subjects and the subjects of the Fukuoka body composition study. Results : FMI was lower and FFMI was higher in this study's subjects compared to the subjects of the Fukuoka body composition study. FMI was correlated with other obesity indices and several metabolic risk factors. Metabolic risk was higher in children with increased FMI than in children with normal FMI. Conclusion : FMI and FFMI were useful indicators in comparing difference of body composition among children that had different body size and growth. High FMI was related to increase of metabolic risk in children.

• Food Science of Animal Resources
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• v.43 no.5
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• pp.805-825
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• 2023

This experiment aims to investigate the impact of probiotic feed on growth performance, carcass traits, plasma lipid biochemical parameters, intramuscular fat and triglyceride content, fatty acid composition, mRNA expression levels of genes related to lipid metabolism, and the activity of the enzyme in Sunit sheep. In this experiment, 12 of 96 randomly selected Sunit sheep were assigned to receive the basic diet or the basic diet supplemented with probiotics. The results showed that supplementation with probiotics significantly increased the loin eye area, and decreased plasma triglycerides and free fatty acids, increasing the content of intramuscular fat and triglycerides in the muscle and improving the composition of the fatty acids. The inclusion of probiotics in the diet reduced the expression of adenosine 5'-monophosphate-activated protein kinase alpha 2 (AMPKα2) mRNA and carnitine palmitoyltransferase 1B (CPT1B) mRNA, while increasing the expression of acetyl-CoA carboxylase alpha (ACCα) mRNA, sterol regulatory element-binding protein-1c (SREBP-1c) mRNA, fatty acid synthase mRNA, and stearoyl-CoA desaturase 1 mRNA. The results of this study indicate that supplementation with probiotics can regulate fat deposition and improves the composition of fatty acids in Sunit sheep through the signaling pathways AMPK-ACC-CPT1B and AMPK-SREBP-1c. This regulatory mechanism leads to an increase in intramuscular fat content, a restructuring of muscle composition of the fatty acids, and an enhancement of the nutritional value of meat. These findings contribute to a better understanding of the food science of animal resources and provide valuable references for the production of meat of higher nutritional value.

• Membrane Journal
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• v.34 no.1
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• pp.50-57
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• 2024

In this experiment, Pd-Ag-Cu membrane was manufactured using electroless plating on an α-Al₂O₃ support. Pd, Ag and Cu were each coated on the surface of the support through electroless plating and heat treatment was performed for 18 h at 500℃ in H₂ in the middle of electroless plating to form Pd alloy. The surface of the Pd-Ag-Cu membrane was observed through Scanning Electron Microscopy (SEM), and the thickness of the Pd membrane was measured to be 7.82 ㎛ and the thickness of the Pd-Ag-Cu membrane was measured to be 3.54 ㎛. Energy dispersive X-ray spectroscopy and X-ray diffraction analysis confirmed the formation of a Pd-Ag-Cu alloy with a composition of Pd-78wt%, Ag-8.81wt% and Cu-13.19wt%. The gas permeation experiment was conducted under the conditions of 350~450℃ and 1~4 bar in H₂ single gas and H₂/N₂ mixed gas. The maximum H₂ flux of the hydrogen separation membrane measured in H₂ single gas is 74.16 ml/cm²·min at 450℃ and 4 bar for the Pd membrane and 113.64 ml/cm²·min at 450℃ and 4 bar for the Pd-Ag-Cu membrane. In the case of the separation factor measured in H₂/N₂ mixed gas, separation factors of 2437 and 11032 were measured at 450℃ and 4 bar.