• Korean Journal of Food Science and Technology
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• v.18 no.3
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• pp.210-214
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• 1986

The culture conditions and cell composition of a hydrogen bacterica, Alcaligenes eutrophus ATCC 17697. were investigated. Optimum pH and temperature for cell growth under autotrophic condition ($H_2$ as energy source, $CO_2$, as crabon source) were around 7.0 and $30^{\circ}C$, respectively. Effect of oxygen partial pressure in the range of 0.059 atm and 0.27 atm on cell growth was also studied. Maximum specific growth rate $({\mu}max=0.31hr^{-1})$ was observed at 0.11 atm of oxygen partial pressure $(H_2:O_2:CO_2=7:1:1)$. The contents of crude protein, nucleic acid and ash in cells were 69.2%, 17.6%, and 3.62%, respectively.

• Journal of Nutrition and Health
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• v.38 no.6
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• pp.455-464
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• 2005

The study was designed to observe the correlation between the eating habits and growth development in 1,574 children (3-6 years old) in Kyunggi-do and Seoul, Korea. The eating habits and nutrient intake were determined by mini dietary assessment and food frequency questionnaire (FFQ). 35.6% children had been practicing an unbalanced diets. Children with unbalanced diet consumed less amount of protein source foods (meat, fish, egg, soy products), vegetables and fruits and had irregular meal time, but more of them preferred sweet foods (ice creme, cookies) and carbonated drinks as snack compared with children in balanced diet. 24-35% children consumed energy, iron (Fe), calcium (Ca), Niacin, Zinc (Zn) less than 75% RDA. Energy intake of children with unbalanced diet was not significantly different from those with balanced diet, but they consumed less amount of niacin, Fe, Ca and Zn than those with balanced diet. By using the relative percentage of standard weight-length-index (WLI), 65.7% children was normal weight, 12.9% was underweight, 13.4% was overweight and 7.9% was obese. However, 11.9% of underweight and normal weight children was so called thin obese since their body fat content was greater than 20%. There were 16.8% underweight in children with unbalanced diet and 12.6% underweight in those with balanced diet. Compared to normal weight, the underweight children significantly consumed less amount of milk and its product, high protein foods, fried foods and fruits, but obese children consumed more high protein source foods (meat, fish, egg, etc) and sweet foods. In conclusion, the eating habits of unbalanced meal was prevalent problem in preschool children which resulting in their health risks. Therefore, it would be needed that new approach for nutrition education to improve eating habits in preschoolers.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.3 no.3
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• pp.165-171
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• 2022

The Chinese crested tern (Thalasseus bersteini) is one of the most globally endangered species, listed as "Critically Endangered (CE)" on the IUCN Red List, with only approximately 30-49 individuals surviving in the wild. Chinese crested terns were discovered to breed in South Korea for the first time in 2016 while conducting a census on uninhabited islands. The Ministry of Environment has declared the breeding habitat of the Chinese crested terns as "Specified Island" to protect this CE species. However, brown rats (Rattus norvegicus) inhabiting the breeding grounds of the Chinese crested terns and Black-tailed gulls may potentially pose a threat to the breeding of these avian species. Therefore, we conducted a study on the feeding behavior of brown rats involving stable isotope analysis to determine their food sources. Fecal analysis showed that brown rats mainly fed on plants, whereas they scarcely fed on animals, such as insects. In addition, the stable isotope analysis showed that the δ¹³C values of brown rats, insects, and Indian goosegrasses were approximately -16 to -11‰, whereas the δ¹³C value of Chinese crested terns that obtained their food from the marine ecosystem was approximately -22 to -18‰. Hence, we conclude that the source of carbon for brown rats on this island is the terrestrial ecosystem. We ruled out the possibility of any direct prey-predator interaction between the brown rat and the Chinese crested tern or Black-tailed gull.

• Food Science of Animal Resources
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• v.43 no.1
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• pp.61-72
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• 2023

The practical use of Korean native black goat skin as a source of gelatin extraction is limited. The objective of this study was to optimize the extraction temperature and time of gelatin from Korean native black goat skin, and to compare the quality characteristics of goat skin gelatin and other commercial gelatin products. Response surface methodology was applied to optimize the extraction temperature and time of gelatin obtained from native Korean black goat skin. The effects of temperature (50℃-70℃) and time (2-4 h) on extraction yield and gel strength were investigated using a face-centered central composite design with 13 experiments. Gelatin extraction from Korean native black goat skin was prepared through the serial processes of alkali pre-treatment, bleaching, neutralization, hot-water extraction, and freeze-drying. Using the optimization plot of Minitab software, the optimized conditions for extracting temperature and time of goat skin gelatin were 59.49℃ and 3.03 h, and the optimized values of extraction yield and gel strength were 12.52% and 263.37 g, respectively. Based on a quality comparison of goat skin gelatin with commercial gelatin, the pH value of gelatin extracted from Korean native black goat skin was 5.57. The color of gelatin extracted from Korean native black goat skin was darker than that of commercial gelatin (p<0.05). Higher emulsifying properties and gel strength of goat skin gelatin were observed when compared to those of commercial gelatin (p<0.05). Therefore, the results of this study indicate that Korean native black goat skin may be a valuable source for gelatin extraction.

• Food Science of Animal Resources
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• v.43 no.2
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• pp.305-318
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• 2023

This study investigated the protein digestibility of chicken breast and thigh in an in vitro digestion model to determine the better protein sources for the elderly in terms of bioavailability. For this purpose, the biochemical traits of raw muscles and the structural properties of myofibrillar proteins were monitored. The thigh had higher pH, 10% trichloroacetic acid-soluble α-amino groups, and protein carbonyl content than the breast (p<0.05). In the proximate composition, the thigh had higher crude fat and lower crude protein content than the breast (p<0.05). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of myofibrillar proteins showed noticeable differences in the band intensities of tropomyosin α-chain and myosin light chain-3 between the thigh and breast. The intrinsic tryptophan fluorescence intensity of myosin was lower in the thigh than in the breast (p<0.05). Moreover, circular dichroism spectroscopy of myosin revealed that the thigh had higher α-helical and lower β-sheet structures than the breast (p<0.05). The cooked muscles were then chopped and digested in the elderly digestion model. The thigh had more α-amino groups than the breast after both gastric and gastrointestinal digestion (p<0.05). SDS-PAGE analysis of the gastric digesta showed that more bands remained in the digesta of the breast than that of the thigh. The content of proteins less than 3 kDa in the gastrointestinal digesta was also higher in the thigh than in the breast (p<0.05). These results reveal that chicken thigh with higher in vitro protein digestibility is a more appropriate protein source for the elderly than chicken breast.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.1
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• pp.171-180
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• 2007

The purpose of this study is to determine the possibility of using Flos Sophora japonica as natural health food source. To accomplish this purpose, the contents of general and antioxidative nutrients of Flos Sophora japonica a were measured. The contents of carbohydrate, crude protein, crude lipid and ash are 67.76%, 19.87%, 4.61% and 7.76%. And the calories of Flos Sophora japonica Linne was 318.32 Kcal. Total dietary fiber was 25.35% of total carbohydrates. The percentages of water soluble dietary fiber to insoluble dietary fiber were 1.80 % and 23.56 %, respectively. The protein were contained total 18 different kinds of amino acids. The contents of non-essential and essential amino acids were 4,898.78mg and 5,953.51mg. The K was the largest mineral followed by Ca, P and Mg, which means Flos Sophora japonica Linne is alkali material. The contents of saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids were 29.69%, 34.93% and 35.38%. Therefore, the amount of the total unsaturated fatty acid was higher than that of any other plant. The content of vitamin C in Flos Sophora japonica Linne was higher than that of any other plant, which suggest that it could increase blood elasticity. The content of rutin, which is responsible for capillary vessel permeability, was 22.60%. The contents of water soluble antioxidative materials in 1 mL of water-extracted Flos Sophora japonica Linne were 3.9 ${\mu}$g which is comparable to 1233.0 mmol of vitamin C in antioxidant effect. The general nutrients and other antioxidatant bioactive materials in Flos Sophora japonica Linne were also potential materials for good health food. It is expected that follow up study of Flos Sophora japonica Linne through developing processed food and evaluation of their functional properties would provide useful information as a source of medicinal foods.

• Journal of the Korean Society of Food Science and Nutrition
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• v.8 no.1
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• pp.31-36
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• 1979

As a preliminary study to estimate the amount of daily calcium intake of Korean people, the present study was conducted investigating the kinds and amount of food among ordinary Korean food considered to be sources of calcium. The author sampled arbitrarily a total of 165 apartment households in Pusan City which were distributed in seven administration sections. Duration of this study was eight months, from June, 1975 to February, 1976. During summer vacation in this period twenty trained students visited these households where they measured the calcium source food at dinner, and three times this amount was regarded as the total daily intake. Also questionairs itemizing the various kinds of food which were considered to be sources of calcium were given to housewives and collected about two months later. The results are summarized as follows: The major sources of calcium food were milk and anchovy, and the total calcium content taken daily was an average 195.06 mg which was far smaller than the recommended standard. Cooking methods varied according to the kinds of food; for anchovy, the boiled water extract or the part remaining after removing bone and head was used, and for chopped cattle bone, the broth from boiling foe 5 to 6 hours was used. For boiled water extract, during extraction the amount of calcium was increased in the water but smaller than foe fresh anchovy. It is, therefore, desirable to cook and eat edible fish bone instead of discarding it after extraction. The amount of calcium of shrimp and whitebait consumed was considerably less than that of milk or anchovy. Most housewives, about 71%, discarded fish bones which contained a lot of calium before or after cooking them. So, it was considered necessary to find a good method of preparing fish so that it can be eaten palatably together with the bones.

• Journal of Microbiology and Biotechnology
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• v.12 no.2
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• pp.318-326
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• 2002

The pathogenic marine bacterium Vibrio vulnificus is the causative agent of food-borne diseases such as life-threatening septicemia. To better understand this organism's strategies to survive osmotic stress, a mutant that was more sensitive to high osmolarity was screened from a library of mutants constructed by a random transposon mutagenesis. By a transposon-tagging method, putAP genes encoding a proline dehydrogenase and a proline permease were identified and cloned from V. vulnificus. The amino acid sequences deduced from nucleotide sequences of putAP from V. vulnificus were 38 to $59\%$ similar to those of PutA and PutP reported from other Enterobacteriaceae. Functions of putAP genes were assessed by the construction of mutants, whose putAP genes were inactivated by allelic exchanges. When proline as the sole carbon or nitrogen source was used, the putA mutant was not able to grow to the substantial level, revealing the proline dehydrogenase is the only enzyme for metabolic conversion of proline into other amino acids. Although the growth rate of the putP mutant on proline as the sole carbon or nitrogen source was significantly reduced, the mutant still grew. This indicated that at least one more proline permease is produced by V. vulnificus. The putP mutant decreased approximately $2-log_10$ CFU/ml after a hyperosmotic challenge, while the parent strain decreased approximately $l-log_10$ CFU/ml. This result suggests that the gene product of putP contributes to the osmotic tolerance of V. vulnificus.

• Korean Journal of Community Nutrition
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• v.27 no.3
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• pp.245-253
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• 2022

Objectives: This study was conducted to find out if the dietary iron intake of Koreans estimated by 2 different methods (iron content sources) using the food intake data from the Korea National Health and Nutrition Examination Survey (KNHANES) are comparable. One method was based on the KNHANES's Food & Nutrient Database (FND) derived mainly from the Korean Food Composition Table and the other used the iron content (IC) of food samples processed in the Korean Total Diet Study (KTDS). Methods: Dietary intake data from the 2013-2016 KNHANES was used to select representative foods (RFs) in KTDS for iron analysis. Selection of the RFs and cooking methods for each RF (RF × cooking method pair) was performed according to the 'Guidebook for Korean Total Diet Studies' and resulted in a total of 132 RFs and 224 'RF × cooking method' pairs. RFs were collected in 9 metropolitan cities nationwide once or twice (for those with seasonality) in 2018 and made into 6 composites each, based on the origin and season prior to cooking. Then, the RF composites prepared to a 'table ready' state for KTDS were analyzed by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Dietary iron intake of the Korean population was estimated using only RFs' intake data based on the 2 sources of iron content, namely FND-KNHANES and IC-KTDS. Results: RFs in KTDS covered 92.0% of total food intake of Koreans in the 2016-2018 KNHANES. Mean iron intake of Koreans was 7.77 mg/person/day by IC-KTDS vs 9.73 mg/person/day by FND-KNHANES. The major food groups contributing to iron intake were meats (21.7%), vegetables (20.5%), and grains & cereals (13.4%) as per IC-KTDS. On the other hand, the latter source (FND-KNHANES) resulted in a very different profile: grains & cereals (31.1%), vegetables (16.8%), and meats (15.3%). While the top iron source was beef, accounting for 8.6% in the former, it was polished rice (19.2%) in the latter. There was a 10-fold difference in the iron content of polished rice between 2 sources that iron intakes excluding the contribution by polished rice resulted in very similar values: 7.58 mg/person/day by IC-KTDS and 7.86 mg/person/day by FND-KNHANES. Conclusions: This study revealed that the dietary iron intake estimated by 2 different methods were quite comparable, excluding one RF, namely polished rice. KTDS was thus proven to be a useful tool in estimating a 'closer-to-real' dietary intake of nutrients for Koreans and further research on various nutrients is warranted.

• Journal of the Korean Society of Food Culture
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• v.26 no.4
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• pp.331-343
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• 2011

A survey of consumer awareness and attitudes was conducted about genetically modified (GM) foods and the labeling regulations. The questionnaires were distributed to 4,620 consumers who lived in a variety of areas in Korea, and 4,076 people responded. The consumers were asked about knowledge, labeling information, and the source of obtaining information about GM foods. More than 11.5% of the consumers had never heard about GM foods and 86.9% of consumers had less than a normal level of knowledge about GM foods. No statistically significant relationship was found between genders, but the teachers group had moderate knowledge (p<0.001). In total, 28.4% of consumers did not know the GMO labeling regulations. They answered that the reason to buy GM food was do not know>nothing wrong>create benefit>think as safe>inexpensive. The answers to the question of what was the first benefit were: solve food shortage>functional and nutritious food>cultivate in bad condition>nothing>various cultivars. They answered that the worst factor was the next generation effect>environmental disruption. Regarding the development of GM food in Korea, males answered do not know>stronglyrecommend>defer>strongly suppress. Female answered: don't know>defer>strongly recommend>strongly suppress. More than half of the respondents did not have much information about GM foods; 88.3% of respondents answered they did not have educational experience about GM food.