• Journal of Environmental Health Sciences
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• v.32 no.1 s.88
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• pp.53-59
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• 2006

This study was carried out to investigate the physicochemical characteristics with the elapsed time of $1\~10$ minutes after adding green tea leaves in the tap water. The results are summarized as follows: 1. $UV_{254}$ measurement increased sharply in direct opposition to increasing conductivity slowly. It is expected that the water soluble organic matters were better extracted than minerals. 2. Residual chlorine decay coefficients evaluated by assuming first-order reaction was increased in proportion to adding weights of green tea leaves. 3. In DBP formation experiments, residual chlorine decreased when reaction time was elapsed. whereas DBPs such as HAAs and THMs increased with the passing of time. From these results, it was showed that residual chlorine decay was related with the formation of DBPs. Therefore, use of boiled tap water in preparation of green tea is suggested if the residual chlorine in the tap water is high.

• Journal of the Mineralogical Society of Korea
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• v.17 no.1
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• pp.23-35
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• 2004

The weathering characteristics of periodically submerged sedimentary rocks in the Sayeon dam, Ulsan was examined by field work, electron probe micro-analysis, X-ray diffraction, and X-ray fluorescence spectrometry. Analysis of fracture zone and exfoliation showed the submerged sedimentary rocks have undergone severe mechanical weathering. Mechanical weathering in the water-rock interface accelerated chemical weathering, such as dissolution and alteration of the most of minerals except for quartz in the weathering zone. The dissolution of carbonates specially calcite, is remarkable creating the cavities, whereas formation of minerals including clay minerals is not active. The sedimentary rocks have been periodically submerged for a certain period of time, and have repeated freezing and thawing. This mechanical weathering favored infiltration, which accelerated mineral dissolution. The high content of easily soluble carbonate of the sedimentary rocks is likely the major cause of intense chemical weathering. The dissolved elements within the infiltrated water interrupted the occurrence of clay and weathering minerals, and expend fractures by infiltrated water accelerated weathering process.

• Korean Journal of Soil Science and Fertilizer
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• v.26 no.3
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• pp.204-214
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• 1993

The purpose of this study was to elucidate the chemical changes and formation of sulfur minerals following reduction and subsequent oxidation of the acid sulfate soils derived from the fluvio-marine plains in Gimhae area. Changes in pH, Eh and water soluble $SO_4$, Fe, Al, K, na and Ca were determined in the soil under the reduced and oxidized conditions. These chemical properties were related to the formation of the pyrite and jarosite, the major sulfur minerals in the acid sulfate soils. On incubation, suspension pH tended to increase with decreaseing Eh in the reduction periods. Jarosite formation was favored by maintaining continuous low pH(below 4.0) and high Eh(above 400mV) during the oxidation periods, however, the conditions were not favorable for the soils with $Ca(OH)_2$. Water soluble K increased by reduction but decreased by oxidation, while the jarosite of the soil with $Ca(OH)_2$ was dissolved even under the oxidation conditon, resulting in rapid increase of water soluble K. The water soluble Ca decreased rapidly, indicating that gypsum was formed with $Ca(OH)_2$ during the oxidation periods. The formation of jarosite was favored by the oxidation condition, and hindered by the reduction condition. But the formation of pyrite was favored by reduction and hindered by oxidation. When the troll was treated with $Ca(OH)_2$, Jarosite was dissolved in both oxidized and reduced conditions.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.4
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• pp.515-524
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• 2001

Two experiments using growing and finishing pigs (Landrace$\times$Duroc$\times$Yorkshire) were conducted to determine the effects of different levels of vitamins and trace minerals (VTM) on growth performance, nutrient digestibility, carcass characteristics and meat quality of growing-finishing pigs, and to evaluate the suitability of vitamin-mineral levels commonly used in the swine industry in Korea. A total of 120 three crossbred (Landrace$\times$Duroc$\times$Yorkshire) growing (Experiment I: 20.90 0.44 kg average initial body weight) and finishing (Experiment II: 53.55 0.97 kg average initial body weight) were used in 6 and 9 weeks feeding trials, respectively. Pigs were allotted on the basis of sex and weight to 5 treatments with 6 replications per treatment with 4 pigs per pen in a completely randomized block design. Treatments were: 1) control, 2) fat soluble vitamin 200% vs. control, 3) water soluble vitamin 200% vs. control, 4) trace mineral 50% vs. control, 5) trace mineral 200% vs. control. In experiment I, during the overall experimental period (0 to 6 weeks, 21 to 54 kg body weight), ADG of the 200% trace mineral supplemented group was significantly higher than that of the 50% trace mineral supplemented group. There were no significant differences among other the treatments. Digestibility of crude protein was lowest in mineral 50% supplemented group (p<0.05). Calcium digestibility was significantly higher in the 200% fat soluble vitamin supplemented group than in the other treatments (p<0.05). In experiment II, during the overall experimental period (0 to 9 weeks, 54 to 106 kg body weight), growth performance was not significantly affected by dietary vitamin and trace mineral levels. However, increasing level of water soluble vitamins at the level of 200% compared to control had a tendency to improve the overall growth performance. Overall carcass characteristics except for carcass length did not differ among pigs fed the dietary treatments. Loin eye area, pH, drip loss and shear force of meat were not affected by dietary vitamin and trace mineral levels. There was a trend for less fat content (%) in pork when the level of vitamin and trace mineral was increased, but the difference was not significant. Flavor score was the lowest in control and highest in the 200% fat soluble vitamin supplemented group (p<0.05). Juiciness of muscle was lower in the 200% fat soluble vitamin supplemented group than other dietary treatments, except for trace mineral 50% supplemented group (p<0.05). Based on these results, it is suggested that "typical" commercial levels of vitamin and trace minerals used by feed companies in Korea are sufficient to meet requirement for the maximum growth of growing-finishing pigs. Our results suggests that a reduction in trace mineral levels in commercial diets could be considered to reduce feed cost and nutrient excretion with economic and environmental benefits.

• Journal of Nutrition and Health
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• v.33 no.7
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• pp.717-724
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• 2000

A number of epidemiological studies has indicated lifestyles including dietary habits are closely related to the development of certain forms of cancer. These findings have led several investigators to identify the ways in which these factors mdulate the risk of cancer. Seaweeds are rich sources of non-digestible polysaccharides which possibly posses physiological functions. In vitro studies showed several components in seaweeds inhibit tumor cell growth and mutagenicity of known food mutagens. On the other hand non-digestible polysaccharides of different food sources negatively affect mineral nutrition by decreasing mineral absorption. The objectives of this study was to investigate the effect of major seaweed intake on azoxymethane(AOM) - induced DNA damage a known cancer initiation step and on apparent absorption of calcium and iron. To accomplish these objectives twenty five ICR mice were divided into five groups and fed one of the following diets for 10 days : control diet d, diet containing 10% water-soluble fraction of seamustard or seatangle diet containing 10% water-insoluble fraction of seamustard or seatangle. AOM was injected 6 hours before sacrifice and N7-methylated guanines from the colonic DNA were quantified using a gas chromatography -mass spectroscopy. Fecal samples were collected on days 4 and 8. Caclium and iron contents of the diets and feces were analyzed using an atomic absorption spectrophotometry to determine the apparent absorption of these minerals. Results are as follows. AOM-induced guanine methylation of colon was decreased in animals fed diets containing water-soluble fractions of seamustard or seatangle compared to those in animals fed control diet although only the seatnagle fed group showed statistically significant effect. Apparent calcium absorption was significantly reduced in animals fed diets containing water-insoluble fractions of seaweeds. Iron absorption was significantly decreased and negatively balanced in animals fed diets containing water-insoluble fractions of both seaweeds, and water-soluble fraction of seatangle. In conclusion, seamustard and seatangle intakes may effectively prevent colon tumorigenesis by reducing a carcinogen-induced DNA damages, and more mechanistic studies on possible role of seaweeds on carcinogenesis are required. Also, adverse effects of seaweed diets cintaming a large amount of polysaccharides on mineral nutrition should be carefully monitored.

• Korean Journal of Food Science and Technology
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• v.14 no.3
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• pp.276-282
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• 1982

The UHT treatment and consequent storage effect on nutritional value of milk are discussed. Compared with the conventional sterilization the UHT treatment of milk represents a relatively small thermal stress. During UHT processing, nutritive value of protein, fat, carbohydrates, fat-soluble vitamins and minerals are generally unaffected. Nutritive value of some water soluble vitamins and protein are adversely affected in a small degree during storage. It has been recommended that UHT milk has best nutritional and organoleptic qualities on storage under refrigeration. Some unsolved future problems are also suggested.

• The Korean Journal of Community Living Science
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• v.28 no.4
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• pp.525-535
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• 2017

The purpose of this study was to compare the of ash and minerals contents in different types of soybeans (Baektae, Seoritae, Heuk Tae and Seomoktae) with different cooking methods. Raw, boiled and pan-fried soybean samples were prepared by the Rural Development Administration. Samples were digested by using a microwave and analyzed using ICP-OES and ICP-MS for determining the ash and minerals contents. Ash content in four raw soybeans ranged from 5.07 to 5.59 g/100g. There was no significant difference in the ash contents in raw and pan-fried soybeans (p>0.05). However, the ash content of boiled soybeans was 9 to 14% lower than that of raw soybeans (p<0.05). The minerals contents of Baektae and Seomoktae were high and the major minerals of various soybeans were K, P, Mg, and Ca, which accounted for ash 60.80-65.61%, 20.73-24.26%, 6.90-8.46% and 5.79-8.60%, respectively. The mineral contents of soybeans were significantly different depending on the type of cultivar (p<0.05), but the tendency was not constant. Because the process of soaking and boiling of soybeans made the soluble minerals elute, the ash and mineral contents were reduced. And process of pan-frying of soybeans make Because process of soaking and boiling of soybeans make soluble minerals elute (Ed- this section is very confused and seems to have 2 sentences combined: please check your intended meaning), the ash and mineral contents were reduced. As the soybeans are cooked by pan-frying, the water in the soybeans is evaporated and the mineral content is concentrated or kept constant. These results can serve as the basic data of mineral content during processing and cooking of soybeans.

• Journal of the Korean Society of Food Science and Nutrition
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• v.14 no.2
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• pp.171-176
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• 1985

The effects of cooking methods by boiling, electric oven and microwave on the proximate composition, minerals and water-soluble vitamins of two major Korean potato varieties (Soomi and Namjac) were studied. The dry matter content was increased after the cooking by the methods of electric oven and microwave, however, the crude fiber content was highly decreased by both methods. The crude ash content was not affected by the cooking methods used. The potassium content was increased by electric oven and microwave methods, and iron content was increased by electric oven baking, however, the copper content was significantly decreased by the electric oven and microwave cooking methods. The macrominerals (phosphorus, magnesium, calcium) and microminerals (zinc, manganese, nickel, lead, cadmium) content present initially in potatoes have not been changed by the cooking methods employed in this study. Relative retention value of ascorbic acid was the lowest and the value of thiamin was the highest in the potatoes cooked by microwave. The retention values of riboflavin and folic acid obtained. after boiling were similar to those after microwave cooking, and both of these treatments were superior to the electric oven baking. The retention values of niacin and vitamin $B_6$ varied between 93 and 100% depending on the cooking methods used. Overall, with a few exceptions, the retention values of water-soluble vitamins in boiled and microwave cooked potatoes were superior to those of the electric oven baked.

• Korean Chemical Engineering Research
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• v.43 no.1
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• pp.153-160
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• 2005

There have been large areas of soil contaminated with high levels of explosives. For this experimental work, 2,4,6-trinitrotoluene (TNT) was tested as a representative explosive contaminant of concern in both aqueous and soil samples and its removal was evaluated using three different chemical treatment methods: 1) the classical Fenton reaction which utilizes hydrogen peroxide ($H_2O_2$) and soluble iron at pH less than 3; 2) a modified Fenton reaction which utilizes chelating agents, $H_2O_2$, and soluble iron at pH 7; and 3) a Fenton-like process which utilizes iron minerals instead of soluble iron and $H_2O_2$, generating a hydroxyl radical. Using classic Fenton reaction, 93% of TNT was removed in 20 h at pH 3 (soil spiked with 300 mg/L of TNT, 3% $H_2O_2$ and 1mM Fe(III)), whereas 21% removed at pH 7. The modified Fenton reaction, using nitrilotriacetic acid (NTA), oxalate, ethylenediaminetetraacetic acid (EDTA), acetate and citrate as representative chelating agents, was tested with 3% $H_2O_2$ at pH 7 for 24 h. Results showed the TNT removal in the order of NTA, EDTA, oxalate, citrate and acetate, with the removal efficiency of 87%, 71%, 64%, 46%, and 37%, respectively, suggesting NTA as the most effective chelating agent. The Fenton-like reaction was performed with water contaminated with 100 mg/L TNT and soil contaminated with 300 mg/L TNT, respectively, using 3% $H_2O_2$ and such iron minerals as goethite, magnetite, and hematite. In the goethite-water system, 33% of TNT was removed at pH 3 whereas 28% removed at pH 7. In the magnetite-water system, 40% of TNT was removed at pH 3 whereas 36% removed at pH 7. In the hematite-water system, 40% of TNT was removed at pH 3 whereas 34% removed at pH 7. For further experiments combining the modified Fenton reaction with the Fenton-like reaction, NTA, EDTA, and oxalate were selected with the natural iron minerals, magnetite and hematite at pH 7, based on the results from the modified Fenton reaction. As results, in case magnetite was used, 79%, 59%, and 14% of TNT was removed when NTA, oxalate, and EDTA used, respectively, whereas 73%, 25%, and 19% removed in case of hematite, when NTA, oxalate, and EDTA used, respectively.

• The Korean Journal of Food And Nutrition
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• v.18 no.4
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• pp.316-324
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• 2005

The objectives of this study were to examine effect of ion chip and yellow soil on the growth and physicochemical characteristics of soybean sprouts. The weight and length increased rapidly in soybean sprouts cultivated for 4 days and then the increases slowed. Ascorbic acid increased rapidly after day 6 in soybean sprouts cultivated with ionized water (I.W), $1.0\%$ yellow soil in tap water (T.W+l.0) and $1.0\%$ yellow soil in ionized water (I.W+l.0). The detected content of minerals such as Mg, Ca, K and Fe in soybean sprouts was higher than other minerals. Iron content was the highest in soybean sprouts cultivated by I.W+1.0. The detected levels of glutamic acid in soybean sprouts cultivated for 4 days with ionized water was higher than in those grown with tap water. In all soybean sprouts, nucleotides such as UMP, CMP, AMP, Hx and soluble free sugars like sucrose, raffinose, stachylose were detected, and the levels of UMP were found to be the highest among nucleotides and sucrose among free sugars.