• Journal of Nutrition and Health
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• v.42 no.4
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• pp.397-405
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• 2009

A trienzyme extraction method (use of ${\alpha}$-amylase, protease and folate conjugase) for food folate assay has been used to release folate from the food matrix. In order to reduce the incubation time with three enzymes, folate values were compared between two incubation protocols; separate incubation (SI, incubated with ${\alpha}$-amylase and conjugase separately for 2 hours after protease treatment) and combined incubation (CI, incubated with ${\alpha}$-amylase and conjugase together for 2 hours after protease treatment) using 88 food items from 12 kinds of fast foods and processed foods. We found that folate values by CI were comparable to or higher than those by SI, indicating that CI might be a better extraction procedure to shorten the entire incubation time. We measured folate contents in 49 fast foods and 26 processed foods by microbiological assay after CI. Mean folate contents of one serving of various burgers ranged from 43.1 to 62.0 ${\mu}g$. One serving of French fries, pizza, sandwich and triangled kimbab contained a mean of 53.3, 28.4, 47.4, and 25.7 ${\mu}g$ of folate, respectively. Folate contents of non-alcoholic beverages were very low, ranging from 1.0 to 5.2 ${\mu}g$/100 g. Some of our values were comparable to the values in the folate database published in Korean Nutrition Society, however, some of the published values were 140 times higher than the measured values in this study. Folate values measured by the more recent modifications here can be used to update Korean folate database to accurately estimate dietary folate intake.

• Journal of Chest Surgery
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• v.36 no.3
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• pp.131-135
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• 2003

Bovine pericardium fixed in glutaraldehyde solution (GA) has been one of the most popular surgical bioprosthesis, however, late calcific degeneration after implantation remains to be solved. To mitigate calcific degeneration, we posttreated the bovine pericardium with amino acids after GA fixation. Material and Method: 40 small pieces of bovine pericardia were fixed in 0.625% GA solution with 4 g/L $MgCl_26H_2O$as a control group (group 1). 40 pieces fixed in the same GA solution were posttreated with 2% chitosan solution (group 2) and the other 40 pieces posttreated with 8% glutamate (group 3). These were implanted into the belly of forty Fisher 344 rats subdermally and extracted at f month, 2 months, 3 months and 4 months after implantation. Result: With atomic absorption spectrophotometry we measured the deposited calcium amount and the results were as follows; 2.01 $\pm$0.13 mg/g in group 1, 2.34$\pm$0.73 mg/g in group 2, 2.49$\pm$0.15 mg/g in group 3 at 1 month after implantation, and 3.57$\pm$0.15 mg/g in group 1, 3.52$\pm$0.92 mg/g in group 2, 3.46$\pm$0.12 mg/g in group 3 at the second month. But 5.45$\pm$0.42 mg/g in group 1, 3.22 $\pm$1.31 mg/g in group 2 and 4.20$\pm$0.55 mg/g in group 3 at the 3rd month, which have statistical significance in group 2 (p<0.05). Finally at 4th month, 6.01$\pm$1.21 mg/g in group 1, 3.78$\pm$1.82 mg/g in group 2, 3.92$\pm$0.92 mg/g in group 3, which also have statistical significance (p < 0.05). Conclusion: This means posttreatment with 2% chitosan shows meaningful calcium mitigation effects after 3rd month on subcutaneously implanted bovine pericardium in the rat models but 8% glutamate shows mitigation effect after 4months in this experiment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.2
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• pp.315-321
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• 2002

This study was focused on identifying the difference of food preference according to body size of elementary school boys in Daejeon city. In order to measure the food preference, the degree of liking by means of a 5-point Hedonic scale was asked to 198 boys of 5th grade from six schools throughout Daejeon for 144 food items in 17 food groups composed of main dish, side dish and dessert : cooked rice, noodles or breads, as main dish, kimchi, tang.guk.zzigae, gui, zzim, bokeum, fried.pan-fried, jorim, muchim.namul or jangachi, as side dish, fruits, beverage, milk, rice cake or anacks, as dessert and for best preferred taste among five basic. The survey was conducted in rune, 1997 by questionnaires. Overall food preference of the subject was inclined to be higher in most of dessert food : fruits, beverage, milk or snacks, but to be lower in side dishes of Korean conventional food : jangachi, muchim, namul, jorim, kimchi and tang.guk .zzigae. The percentage of boys preferring cocked rice to noodle or bread as main dish was as much almost double in overweight boys as those of underweight or normal weight boys. None of the food group among 17 groups was significantly different in the food preference by body size of the subjects. However, food preference score of overweight group showed a trend to be higher in 11 food groups except less calorie-dense food groups such as fruits, noodles, rice cake, cooked rice, soup and stew and braised food (jorim) than normal or underweight group, and they seemed to prefer especially high-protein and high-fat foods. Being based on 3 points of preference score as the criterion for comparison, underweight group showed higher preference only in fruits group but showed lower preferences in 12 food groups among 17 groups than other groups.

• Economic and Environmental Geology
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• v.54 no.6
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• pp.671-687
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• 2021

This study investigated the firing temperature and thermal deformation process of roof tiles excavated from the connected stone-mound tomb in Seokchon-dong, Seoul, based on mineralogical and physical properties. A large number of roof tiles were excavated from the tomb site and some roof tiles were deformed by heat and were fired in uneven conditions. The colors of original roof tiles and their cores are mostly yellowish-brown, with high water absorption over 12%, containing fine-grained textures and some minerals such as quartz, feldspars, amphibole, and mica. It is estimated that the original roof tiles were fired below 900℃ in oxidation condition, showing loose matrices and mica layers by scanning electron microscopy. However, deformed roof tiles have the uneven surface color of reddish-brown and bluish-gray, and those cross-sections have sandwich structures in which dense reddish-brown surface and porous grey core coexist. They contained mullite and hercynite, so it was estimated to have been fired over 1,000℃, with 0.81~11% water absorption. In some samples, bloating pores by overfiring were observed, which means that they were fired at more than 1,200℃. In addition, the refirng experiments that the original roof tile was fired between 800℃ and 1,200℃ were carried out to investigate the physical and mineralogical properties of roof tiles compared to deformed ones. As a result, the water absorption decreased rapidly and the mineral phase started to change over 1,000℃. As the temperature gradually rises, the matrices are partially melted and recrystallized, resulting in similar thermal characteristics of deformed roof tiles. Therefore, the roof tiles from ancient tombs in Seokchon-dong seem to experience the secondary high temperature of 1,000 to 1,200℃ under uneven firing conditions, resulting in deformation characteristics such as shape transformation and mineral phase transition. It is considered to have been related to cremation rituals at the tombs of Seockchon-dong during the Baekje period.