• Applied Biological Chemistry
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• v.16 no.2
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• pp.60-77
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• 1973

The non-enzymatic browning phenomenons of red ginseng were studied to identify these compounds which function as the factors for browning. The samples were classified into five divisions; Fresh ginseng, blanched ginseng, sun dried red ginseng, dehydrated red ginseng, and browning accelerated red ginseng respectively, and the various compounds in each of them were analyzed quantitatively and investigated the compounds which were thought to function for browning during the drying and the dehydration processes; the results were as follows. 1. The chemical compositions among five divisions did not show any difference except a) total and reducing sugars, b) total acids, c) water soluble extracts; a) and b) were decreased during the drying process, c) was decreased about 6-7% in red ginseng divisions. 2. Sixteen free amino acids; asp., thr., ser., glu., gly., ala., val., cys., met., ileu., leu., tyr., phe., lys., his., and arg, were identified in each division. Among them the arg, was extremly high. All of the essential amino acids were contained, while generally these amino acids were decreased in drying period and their rates were smaller in dehydrated red ginseng than in sun dried red ginseng. 3. Three kinds of sugars; fructose, glucose and sucrose were identified and other four kinds of unidentified sugars were seperated. The content of sucrose was 80% and all kind of sugars were generally less in red ginseng divisions than in the other two divisions. The decreasing rate of sngars was higher in the sun dried red ginseng than in the dehydrated red ginseng. Especially the decreasing rate of the reducing sugars was high as compared with that of sucrose. 4. Almost all the ascorbic acid was decomposed during the blanching whereas there could'nt be shown any change of the ascorbic acid content during the period of drying. 5. Eleven kinds of volatile acids; acetic acid, propionic acid, acrylic acid, iso-butyric acid, n-butyric acid, isovaleric acid, n-valeric acid, isoheptylic acid, n-heptylic acid, and an unknown volatile acid were identified. They showed a little decrease during the period of blanching perhaps on account of their volatility whereas they were increased in drying period. 6. Six kinds of non-volatile acids; citric acid, malic acid, ${\alpha}-ketoglutaric$ acid, succinic acid, pyruvic acid and glutaric acid were identified. The content of them were decreased during the drying procedures in red ginseng but only that of succinic acid was increased. 7. Three kinds of polyphenols; 3-caffeyl quinic acid, 4-caffeyl quinic acid, 5-caffeyl quinic acid and an unknown polyphenol were identified. The content of them showed considerable decrease during the drying procedures, especially in sun drying. 8. The intensity of the browning in each divisior was as follows; browning accelerated red ginseng> sun dried red ginseng> dehydrated red ginseng. 9. In the process of red ginseng preparation, a. certain relationship could be found between the decreasing rates of amino acids, reducing sugars, polyphenols and the intensity of browning. Therefore the browning phenomenon may be concluded that nonenzymatic browning reactions of the amino-carbonyl reaction and autoxidation of polyphenols are the most important processes, furthermore, as their reactions could be controlled it is thought to be possible to accelerate effectively browning within a relatively short period.

• Journal of Nutrition and Health
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• v.44 no.5
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• pp.416-427
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• 2011

This study investigated the association among parental socioeconomic level, overweight, and eating habits with diet quality in Korean sixth grade school children. A 3-day dietary survey was conducted, and a questionnaire and anthropometric data were collected from the Korean child obesity cohort (320 boys and 345 girls). The children were classified into two groups (low or high level) based on monthly household income and paternal and maternal education status. Lower maternal education status was associated with a higher risk for overweight in girls (odd ratio, 1.91; 95% confidence interval 1.07-3.44), whereas belonging to a higher socioeconomic group in terms of parental income or parental education level resulted in the consumption of significantly more fruit. Boys did not show significant differences in the intake of most nutrients or diet quality regardless of socioeconomic status. However, girls in the lower socioeconomic group had a lower food habit score (higher frequency of breakfast skipping and ramen noodle consumption), diet quality, and intake of nutrients (carbohydrate, vitamin C, potassium, and fiber) than those in the higher socioeconomic group. Therefore future nutrition policies and interventions should support parents and children with lower socioeconomic status to develop health-related behaviors that may prevent childhood overweight.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.2
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• pp.94-101
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• 1989

Transport properties of 2DEG at AlGaAs/GaAs interface such as average electron energy, flight distance, each valley occupancy ratio, average electron velocity for various fields are investigated by MONTE-CARLO method. As the electric field increases, more electrons transit drastically from (000) valley to (000) upper valley. This phenomenon shows the nonstationary effect such as velocity overshoot. The duration of the transient decreases from about 1.4 psec for electric field E = 7KV/cm to about 0.7 psec for 12KV/cm. The average electron velocity during transient transport in 2DEG is about 8 times the steady-state velocity for E = 12KV/cm at room temperature. In comparison with bulk GaAs the peak velocity in the 2DEG is higher than that in even pure bulk GaAs at electric field E = 7 KV/cm. On the basis of the fact that the electrons in the 2DEG have larger peak velocity and shorter transient time of velocity than those in the bulk GaAs, it is suggested that the device with 2DEG may obtain higher mobility than that with bulk GaAs.

• Journal of Nutrition and Health
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• v.35 no.4
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• pp.464-472
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• 2002

This study was conducted to investigate dietary and other factors affecting bone mineral density in young Korean collage women. Thirty subjects were recruited; the mean age was 22.1 years and the mean age at menarche was 12.6 years. Bone mineral density (BMD) was measured in the spine (LS), femoral neck (FN), ward's triangle (WT), and femoral trochanter (FT) by Dual Energy X-ray Absorptiometry (DEXA), and physical activity was assessed by a questionnaire. Dietary intake data were obtained 8 times by using a 24 hour recall method to evaluate the subjects' usual diet. Bone mineral densities of lumbar spine, femoral neck, ward's triangle and femoral trochanter were 1.149 g/$\textrm{cm}^2$, 0.980 g/$\textrm{cm}^2$, 0.936 g/$\textrm{cm}^2$ and 0.759 g/$\textrm{cm}^2$ respectively. The met energy intake of subjects was 1,790 kcal, and calcium and iron intakes were found to be inadequate compared to the Korean RDA. The BMD of the lumbar spine was significantly and positively related to the BMI and intake of vitamin C, carbohydrate, potatoes, fruits and plant food. The BMD of the femur (FN, WT, FT) was positively related to the BMI, to carbohydrate and fruit intake, and to the percentage of plant food in total food intake. Multiple recession analysis showed that fruit intake was significantly related to the BMD of the LS. The subjects'ages and fruit intakes were significantly related to the BMD of the femur (FN, WT, FT). These results indicate that higher fruit intakes may have a beneficial effect on bone mineral density.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.5
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• pp.716-724
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• 2015

Trienzyme extraction coupled with microplate assay (Lactobacillus casei subsp. rhamnosus) was validated and applied for the determination of folate (vitamin B9) in Korean ancestral rite foods. Foods included five Guk (Tang), eleven Sookchaes, eight Jeoks, nine Jeons, six Jjims, and twenty desserts. Folate was detected in all samples: Guk (Tang) 4.62~18.84, Sookchae 6.13~48.40, Jeok 5.49~49.50, Jeon 6.96~30.77, Jjim 10.34~38.88, and desserts $3.33{\sim}49.55{\mu}g/100g$. The lowest folate content was observed in Sikhye ($3.33{\mu}g/100g$), whereas the highest was observed in Songhwa-dasik ($49.55{\mu}g/100g$). Folate analyses of certified reference materials, BCR-121 (whole meal flour) and BCR-487 (pig liver), showed good recoveries of 90.0% (0.45 mg/kg) and 92.4% (12.3 mg/kg), respectively. The recoveries (96.0 to 106.2%) obtained by analyzing eight spiked samples with different matrices also showed good accuracy. Both repeatability and reproducibility were less than 5%, indicating good precision. The quality control chart (n>30) obtained by running commercial folate fortified-wheat flour once a week for about 10 months showed that all assays were under control. All validation method and analytical quality control results showed that folate contents in Korean ancestral rite foods produced by microplate assay were reliable enough to be used for the construction of a national folate database.

• Journal of agriculture & life science
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• v.46 no.4
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• pp.129-139
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• 2012

This study was carried out to evaluate the chemical properties and functional characteristics, such as general composition and bioactivity compounds contents of fresh and blanched (at $95^{\circ}C$, for 5min) garlic shoot from Namhae. Also, evaluated antioxidant and antimicrobial activities of water and ethanol extract of fresh and blanched garlic shoot. The moisture content of fresh garlic steam was $ 85.14{\pm}0.35%$, crude protein and crude lipid were $0.79{\pm}0.26%$ and $2.96{\pm}0.03%$ respectively. Vitamin C content was higher in fresh garlic shoot ($7.07{\pm}0.84mg/100g$) than blanched. Total phenol and total chlorophyll contents were respectively $16.93{\pm}1.17mM/g$ and $6.70{\pm}0.46mg/g$ in fresh garlic shoot. Allicin content of blanched garlic shoot was $128.63{\pm}1.59mM/g$. This content was 1.82 times higher than the fresh garlic shoot. Total pyruvate content was higher in fresh garlic shoot ($24.63{\pm}1.59mM/g$), but thiosulfinate was higher in fresh garlic shoot. Total flavonoide was the highest in water extract of blanched garlic shoot ($3.67{\pm}0.00mM/g$). ABTS radical scavenging activity of water extract form blanched garlic shoot was $85.09{\pm}0.28%$, which was higher than the other extracts. NO radical scavenging activity of ethanol extract from blanched garlic shoot was significantly higher than the extracts from fresh garlic shoot. Antibacterial activity to S. aureus, S. enterica, B. cereus and E. coli was only indicated in water extract of fresh garlic shoot.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.4
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• pp.518-525
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• 2010

The purpose of the study was to examine health-related behaviors and nutrient intake in relation to job stress level of police officers. Total of 166 police officers working in Jeonbuk area participated in the study. The study was conducted from February to March, 2009. Subjects were given self-administered questionnaire on their general health status, dietary and health-related habits. Nutrient intake was assessed by semi-quantitative food frequency questionnaire. Subjects were divided into four groups (very low, low, high, very high) by their job stress level scores. Main concerns of job stress were from 'job demand', 'organizational system' and 'lack of reward'. More than 95% of the subjects were confident of their health status. Health habits, such as drinking, smoking and exercising, were better than that of average Korean men. There were significant differences in dietary habits in relation to job stress level. Lower job stress group showed lower rate of skipping breakfast (p<0.01), more affordable meal time (p<0.05) and better snacking habits (p<0.001). Sweet food preference was higher in lower job stress group (p<0.05). The average calorie intake was $2063\pm532.7$ (88.5% of EER) and there was no significant difference in nutrient intake among job stress levels. However, mean intake of calcium and vitamin $B_2$ was less than 75% of %DRI in higher job stress group. Therefore, further support in nutritional counseling programs to improve dietary behaviors and health habits and to reduce job concerned stress of the police officers will be necessary.

• The Korean Journal of Food And Nutrition
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• v.29 no.1
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• pp.65-72
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• 2016

Black tomato (Lycopersicum esculentum) is known to have more ${\beta}-carotene$, lycopene, and vitamin C than general red-colored tomatoes. In this study, we evaluated the quality properties, antioxidant activities and sensory characteristics of black tomato cookies. Cookies were prepared by replacing 0, 1, 3, 5, and 7% of flour with black tomato powder. Density of black tomato cookies tended to be decreased between control (1.20) and 3% added groups (1.12). pH value was decreased from control (6.66) to 7% added group (5.16). Spread factor and loss rate were increased with increasing amounts of black tomato powder. Hardness was gradually increased from $107.77g/cm^2$ in control to $170.50g/cm^2$ in 7% added group. Color measurement indicated that L-value (brightness) was highest in control (70.46) and lowest in 7% added group (45.23); whereas, a-value (redness) increased while b-value (yellowness) tended to decrease with increasing amounts of black tomato powder. Total polyphenol contents and DPPH radical scavenging activities were directly proportional to the amount of black tomato powder. Consumer preference scores in color and flavor of black tomato powder added group were higher than those of control. Characteristic strength test was not significantly different among the groups. Overall, the results indicated that adding 5% black tomato powder is desirable for making black tomato cookies.

• Korean Journal of Food Science and Technology
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• v.38 no.4
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• pp.475-482
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• 2006

The quality characteristics and functional properties of fermented soybean by lactic acid bacteria (FSB) were investigated and compared with those of soybean (control) and commercial cheonggukjang Powder (CGP). The crude protein, lipid, and fiber contents of FSB were similar to those in CGP. The vitamin $B_2$ content in FSB (1.4 mg%) was similar to the control (1.3 mg%) whereas it was remarkably low in the CGP (0.2 mg%). The bright yellow color of FSB determined by Hunter's colormeter was quite different from the dark reddish brown color of the CGP. The pH of FSB was the lowest and thee amino-nitrogen was 517.2 mg%, which was higher than that in CGP (468.1 mg%). Glutamic acid, aspartic acid and leucine were the most abundant amino acids. In particular, the increase in the glutamic acid level was noticeable in FSB. The fatty acid compositions of FSB and CGP were similar to the control. However, the sucrose and fructose levels were lower after fermentation but the glucose level was higher. The results of isoflavone analysis by HPLC showed that the levels of daidzein and genistein in FSB were as much as 48.33 and 52.82 mg%, respectively, which is higher than that found in CGP. The DPPH free radical scavenging effects of FSB and CGP were 1.8 times higher an those of the control. The fibrinolytic activity determined by the diameter of the lysed area on the fibrin plate was the most effective in FSB. In conclusion, it is believed that FSB has a similar or higher quality than CGP. Therefore, FSB is expected to be good functional food material.

• Journal of Nutrition and Health
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• v.55 no.3
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• pp.321-329
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• 2022

Riboflavin and its derivatives, flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), are key components of mitochondrial energy metabolism and oxidation-reduction reactions. Proposed dietary reference intakes for Koreans (KDRIs), that is, estimated average requirements (EARs), for riboflavin, based on current knowledge of riboflavin and riboflavin derivative levels, and glutathione reductase activity, are 1.3 mg/d for men aged 19-64 years and 1.0 mg/d for women aged 19-64 years. By applying a coefficient of variance of 10%, reference nutrient intakes (RNIs) were set at 1.5 mg/d for men aged 19-64 years and 1.2 mg/d for women aged 19-64 years. Likewise, EARs and RNIs of riboflavin intake were proposed for all age groups and women in specific life stages such as pregnancy. Mean adult riboflavin intake for adults aged ≥ 19 years was 1.69 mg/d in Korea National Health and Nutrition Examination Survey (KNHANES) 2020, which was 124.9% of EAR according to the 2020 KDRIs. In the 2015-2017 KNHANES study, the mean riboflavin intake from foods and supplements was 2.79 mg/d for all age groups, and 32.7% of individuals consumed less riboflavin than EAR according to the 2020 KDRIs. For those that used supplements, mean intakes were 1.50 mg/d for riboflavin from foods, 10.26 mg/d from supplements, and 11.76 mg/d from food and supplements, and 5.5% of individuals consumed less riboflavin than EAR. Although the upper limit of riboflavin has not been established, the merits of increasing supplement use warrant further consideration. Also, additional epidemiologic and intervention studies are required to explore the role of riboflavin in the etiology of chronic diseases.