• Journal of Nutrition and Health
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• v.31 no.8
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• pp.1355-1364
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• 1998

This study was planned to investigate the effect of 40 plant ethanolic extracts on antioxidant activities in vitro. The total phenolics, $\beta$-carotene, $\alpha$-tocopherol and selenium contents were also determined . Antioxidant activities fo the ethanolic extracts(0.02%, w/w) in the soybean oil were measured both by determining the peroxide value (POV) during 35 days of storage at 4$0^{\circ}C$ in a forced draft air-incubator and by determining changes in conductivity at 11$0^{\circ}C$(Rancimat method.). Soybean oil without any additives was used as a control and that treated with 0.02% BHT was used as a positive control. Based on the POV determination, green tea extract was found to be the most effective in stabilizing soybean oil, then followed by long tea, which both of them showed higher antioxidant activities compared to the BHT treatment. The antioxidant activities of them showed higher antioxidant activities compared to the BHT treatment. the antioxidant activities of coffee, cinnamomi cortex, acanthopanacis cortex, black tea, orange peel , instant coffee, peony and crni fructus extracts were stronger compared to the control .By the Rancimat method, green tea leaf and oolong tea leaf, foxglove, acanthopanacis cortex and peony extracts. Compared to other extracts, green tea leaf, black tea leaf, foxglove, acanthopanacis cortex and peony extracts had stronger antioxidative effects in both the POV and Rancimat methods used in this study. ethanolic extracts which showed the stronger antioxidative effect also has the higher contents of total phenolics, $\beta$-carotene, and/or $\alpha$-tocopherol. The antioxidative effect of ethanolic extracts was found to be due to the combined effect of various antioxidants.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.523-526
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• 2004

There are few studies on toxic metals in fruits. Therefore, we examined contents of toxic metals in fruits (n=386) available in Korean markets. The samples were digested with acids, then analyzed by inductively coupled plasma spectrometer (ICP) or atomic absorption spectrophotometer (AAS) for lead (Pb), cadmium (Cd), and arsenic (As). The contents of mercury (Hg) were also determined using a mercury analyzer, Contents of toxic metals in fruits were as follows [minimum-maximum (mean), mg/kg]; Hg 0.0001-0.019 (0.001), Pb 0.001-0.410 (0.013), Cd 0.001-0.035 (0.000), and As 0.001-0.210 (0.017). Our results showed that metal contents in fruits in Korean markets were similar to those reported in other countries. Average weekly intakes of Hg, Pb, and Cd from fruits are about 1-2% of Provisional Tolerable Weekly Intakes (PTWI) set by FAO/WHO Joint Food Additive and Contaminants Committee for safety evaluation.

• Journal of the Korean Society for Nondestructive Testing
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• v.20 no.1
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• pp.33-37
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• 2000

The 1-3 piezoelectric composite transducer with 75 volume percents PZT was fabricated by the dicing-filling method. The resonance modes of the 1-3 transducer have been studied with electric impedance measurement as a function of frequency. The fundamental frequencies of the planar and thickness mode were observed at 0.95MHz and 1.63MHz respectively, but the lateral mode was not observed. In the thickness mode, the electromechanical coupling coefficient of the 1-3 piezoelectric composite transducer, 0.54, was very closed to that of the single phase PZT(0.52). The pulse-echo response by exciting the 1-3 transducer with an electric pulse was observed from the water/reflector interface, and analyzed bandwidth by the spectrum of the impulse response. The quality factor Q for the 1-3 transducer was observed as 1.5 smaller than that of the single phase(80) and then the 1-3 transducer may be used to the broad band type transducer applications.

• Journal of Food Hygiene and Safety
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• v.15 no.3
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• pp.179-185
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• 2000

Daily intakes of 14 preservatives were evaluated by using their maximum permitted levels(MPL) and national food disappearance data in 1998. The estimated daily intake (EDI) of each preservatives were compared with corresponding acceptable daily intakes (ADIs). EDIs of dehydroacetic acid, sodium dehydroacetate, $\rho$-hydrobenzoic acid ester, propionic acid, sodium propionate and calcium propionate were less than 2% of ADI and judged to be safe. However, EDI of sorbic acid and potassium sorbate were 76.61 mg/person/day and it reached 5% of its ADI.. EDI of benzoic acid and sodium benzoate were 85.65 mg/person/day and it reached 31% of its ADI. The highest intake of benzoic acid came from carbonated drink.

• Journal of Food Hygiene and Safety
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• v.16 no.3
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• pp.178-187
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• 2001

A study has been performed to estimate the average and high (90th percentile of consumers-only) daily intakes of sorbates by age-sex groups (> 3 years old) in Korea. The estimation of daily intakes was based on individual-based dietary intake data in ‘National Health and Nutrition Survey in 1998’and the contents of sorbates from samples. The estimated daily intakes (EDI) of sorbates for average consumers ranged from 0.09 mg/kg/bw/day to 0.51 mg/kg bw/day corresponding to 0.4-2.1% of acceptable daily intake (ADI). For high consumers, the range of EDI of sorbates was 3.42-14.65 mg/kg bw/day corresponding to 13.7-58.6% of ADI. Foods that contributed most to the daily intakes of sorbates for all age-sex groups were processed fish products, processed meat products, and salted floods. There was an inverse relationship between age and the consumption of sorbates for average and high consumers, whereas no marked pattern was emerged by sex categories. The intake levels of sorbates even among high consumers were below the ADI in Korea.

• Korean Journal of Food Science and Technology
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• v.36 no.3
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• pp.375-378
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• 2004

There are few studies on toxic metals in crustaceans available in Korea. Therefore, this study was conducted to estimate content of toxic metals in crustaceans (n=58). Samples were digested with acids and analysed by inductively coupled plasma spectrometer (ICP) or atomic absorption spectrometer (AAS) for lead (Pb), cadmium (Cd), and arsenic (As). Mercury (Hg) contents were determined using mercury analyzer. Toxic metal contents [minimum-maximum (mean), mg/kg] in crustaceans were as follows; Hg 0.004-0.28 (0.06), Pb ND-0.31 (0.03), Cd 0.003-0.92 (0.14), and As 0.01-35.9 (6.63). Our results demonstrated that metal contents in crustaceans on Korean markets were similar to those reported in other countries. Our average weekly intakes of Pb, Cd, and Hg from crustaceans were lower than 1% of Provisional Tolerable Weekly Intakes (PTWI) set by Joint FAO/WHO Expert Committee for food safety evaluation.

• Journal of Food Hygiene and Safety
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• v.16 no.1
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• pp.53-60
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• 2001

A study has been carried out to estimate the average daily intakes of sorbates, benzoates, and and esters of $\rho$-hydroxybenzoic acid commonly used in Korea. The estimation of daily intakes was based on individual dietary intakes in “National Health and Nutrition Survey in 1998”and the the contents of preservatives from 264 samples. Estimated daily intakes(EDI) of sorbates, benzoates, esters of $\rho$-hydroxybenzoic acid were 0.22, 0.015, and 0.004 mg/kg bw/day, respectively. When assuming the standard body weight of 55 kg for Korean, ratios to acceptable daily intake (ADI) of sorbates, benzoates, and esters of $\rho$-hydroxybenzoic acid were 0.88, 0.30, and 0.04%, respectively.

• Korean Journal of Food Science and Technology
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• v.36 no.1
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• pp.158-161
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• 2004

To determine rapid and reliable analytical method for ochratoxin A detection in cereal-based Korean traditional foods, ochratoxin A content was measured by high-performance liquid chromatography (HPLC) with immunoaffinity column clean-up. Recoveries of ochratoxin A in tested samples ranged from 68.4 to 85.3%. Occurrences of ochratoxin A were 15, 10, and 5% for Kochujang, Deonjang, and Kanjang, respectively. None was detected in Sunsik (mixed cereals). Average levels of ochratoxin A ranged from $0.5\;to\;1.3{\mu}g/kg$, lower than maximum residue level of $5-50{\mu}g/kg$ of ochratoxin A recorded in foreign food code.

• Korean Journal of Food Science and Technology
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• v.36 no.6
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• pp.872-878
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• 2004

Food products selected based on their annual sales and international acrylamide research data were analyzed for quantitation of acrylamide. Samples including raw food, substitute meal, snack, drink, and sauce products were analyzed by LC/MS/MS methods adopted by PDA. Upon comparison, concentrations of acrylamide in these products were similar to those analyzed in other countries.

• The Journal of Engineering Geology
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• v.5 no.2
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• pp.129-138
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• 1995

To elucidate the effects of flow rate on the hydraulic fracturing property of andesite, the hydraulic fracturing tests were conducted under three flow rates. As the tests are conducted with 1ml/min, 2ml/min and 3 ml/min under the constant axial load of 40 kN, the breakdown pressures of andesite seem to be constant as 163kg/cm$^2$. The hydraulic fracturing tests were carried out under the temperatures of five stages to elucidate the effects of temperature variation on hydraulic fracturing property of granite. As the tests are carried out under the constant flow rate of 1.7ml/min, with the axial load of 40kN, the breakdown pressures of granite are 168kg/cm$^2$ at room temperature, and 124kg/cm$^2$ at 20$0^{\circ}C$. The breakdown pressure decreases about 25% than that of room temperature with increasing the temperature. Under the controlled flow rates, the initiation pressures of the microcracks of granite are well coincided with the breakdown pressures and these results are also confirmed by the levels of acoustic emission.