• Food Science of Animal Resources
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• v.28 no.4
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• pp.437-444
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• 2008

Microbial reduction, physicochemical property, and sensory evaluation of irradiated beef patty were investigated. The microbial counts of refrigerated beef patty were reduced to below the number of 3 logs after irradiation at 3 kGy. But no viable microorganism was detected in frozen beef patty irradiated at 3 kGy. Food additives such as nitrite, salt, phosphate and ascorbic acid did not affect on the inactivation of microorganism by irradiation. The irradiation effect on the water holding capacity was not significant, but frozen irradiated beef patty showed higher water holding capacity than refrigerated beef patty. The drip loss of irradiated beef patty did not show significant differences according to irradiation doses. Considering the influence of food additives, the irradiated beef patty mixed with salt and phosphate showed lower drip loss than that without food additives. In refrigerated beef patty, TBARS values were increased with increase of irradiation doses and showed lower values in the beer patty mixed with food additives than that without food additives. The redness of refrigerated beef patty showed highest values at 3 kGy of irradiation and then decreased with increasing irradiation doses, while in the frozen beef patty did not show distinct tendency according to the irradiation doses or food additives. In sensory evaluation, the irradiated beef patty showed unpleasant smell as compared with the non irradiated beef patty, but showed some-what higher score in smell at the sample contained ascorbic acid regardless of irradiation doses.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.4
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• pp.385-390
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• 1999

HPLC method usually has been used for the determination of ATP and its related compounds in fish muscle and fish sauce. But, total amount of ATP related compounds in fish sauce is determined less than that of fish muscle. In order to establish the extract analysis method for ATP related compounds in fish sauce, a new enzymatic method was developed and compared with existing HPLC method. Fish sauce was extracted with chilled perchloric acid and neutralized to Ph 7.0 with potassium hydroxide solution, the extract was used as sample analyzed by HPLC as usual. On the other hand, for sample analyzed by enzymatic method, 1 ml extract solution was pipetted into test tube. To the tube, 0.5ml of mixed suspension adenosinedeaminase (4U), nucleosidephosphorylase (0.02U) and xanthineoxidase (0.03U) suspended in 2.0ml of 1/15 M sodium phosphate buffer solution pH 7.6 and 1.5ml deionized water wereadded for the decomposition of IMP, HxR and Hx to uric acid at $37^{\circ}C$ for 40 minutes. Total uric acid was determined by measuring optical density at 290nm. In HPLC method, salt decreased the total amount of ATP related compounds by $13.6\~16.2\%$ at $2.5\%$ concentration, but no effect in enzymatic method. IMP, HxR and Hx were detected at 254nm, while uric acid at only 290nm. The ratio of the total amount of ATP related compounds by HPLC method was about $45\%$ of that by enzymatic method in fish sauce. Form these results, enzymatic method is more accurate and simple than HPLC method for analysis of ATP related compounds in fish sauce.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.7
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• pp.945-954
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• 2006

The purpose of this study is to present basic data for an improvement of school foodservice by indentifying students' preference level for school meal menu and assessing students' nutrition intake. The subjects participated in this study were 544 high school students on 1st grade served by self-operated school foodservice in Daegu. The frequency analysis, t-test analysis, and correlation analysis were carried out for the data analysis using SPSS 12.0 program. Based on the results toward students' preference and serving frequency, the most frequently offered food was soup sorts and then followed by the categories of boiled rice, kimchi, broiled food and hard-boiled food. Boiled rice, rice with assorted vegetables, mandu soup, salad and braised beef rib were highly preferred to the students. Male students scored higher preference to the menu related with meats than female students. However, the students' preference and serving frequency on the menu were not correlated significantly in this study. A substantial correlation was found between the degree of preference and the rate of intake (p<0.01). It would be generalized that preferences to menu items strongly sffected the level of intake by students. The nutrient analysis of food intake revealed that both male and female students were not consuming sufficient level of calorie, calcium and vitamin $B_2$. In conclusion, the results indicate that the students' preference is a very important variable influencing the consumption level of meal as well as balanced nutrient intake by students served in school foodservice. Menu planning should be integrated into school foodservice management for quality control. As limited control of the menu may also negatively influence on the food leftovers and ecological issues, professionals related to the school foodservice including administers, educators and dieticians need to check up the students' preference regularly and reflect their perception on the menu planning to improve the quality of school foodservice. The nutrient intake currently provided through school foodservice should be also assessed more thoroughly. These data could be incorporated into continuous quality improvement and strategic planning in school foodservice.

• Journal of Korean Society of Forest Science
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• v.79 no.2
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• pp.144-161
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• 1990

Pine forest communities developed in Mt. Palgong, southeastern Korea, were studied phytosociologically, with special reference to multiple management of local forests, and were classified into two communities, Pinus densiflora - Quercus mongolica community(I : mountain forest) and P. densiflora-Climbing plants community (II : valley forest) and six subgroups accompanied by several subgroups. Judging from the coincidence method, the division of communities (vegetation units) was closely related to altitude and topography. Based on vegetation units, a vertical distribution map of pine forest communities was prepared. The species composition(%) of pine forest communities under stratification, in upper and lower tree layer, teas I higher than II, in middle and shrubs lacer II higher than I (Total : Upper 15.5%, Middle 28.4%, Lower 34.6%. Shrubs 21.5%. Sum of mean coverage%i of understory vegetation was II twice as high as I (Total. shrubs 28.4%. forbs 11.4%, Graminoids 11.8%, ferns 1.0%). Based on constance, coverage and d.b.h. class etc., an actual growth and occurrence table of tree species and understory vegetation by vegetation unity were prepared, and could assume a criterion for judging potential dominance-growth conditions.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.789-792
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• 2010

Major impacts of climate change expert that soil erosion rate may increase during the $21^{st}$ century. This study was conducted to assess the potential impacts of climate change on soil erosion by water in Korea. The soil loss was estimated for regions with the potential risk of soil erosion on a national scale. For computation, Universal Soil Loss Equation (USLE) with rainfall and runoff erosivity factors (R), cover management factors (C), support practice factors (P) and revised USLE with soil erodibility factors (K) and topographic factors (LS) were used. RUSLE, the revised version of USLE, was modified for Korean conditions and re-evaluate to estimate the national-scale of soil loss based on the digital soil maps for Korea. The change of precipitation for 2010 to 2090s were predicted under A1B scenarios made by National Institute of Meteorological Research in Korea. Future soil loss was predicted based on a change of R factor. As results, the predicted precipitations were increased by 6.7% for 2010 to 2030s, 9.5% for 2040 to 2060s and 190% for 2070 to 2090s, respectively. The total soil loss from uplands in 2005 was estimated approximately $28{\times}10^6$ ton. Total soil losses were estimated as $31{\times}10^6$ ton in 2010 to 2030s, $31{\times}10^6$ ton in 2040 to 2060s and $33{\times}10^6$ ton in 2070 to 2090s, respectively. As precipitation increased by 17% in the end of $21^{st}$ century, the total soil loss was increased by 12.9%. Overall, these results emphasize the significance of precipitation. However, it should be noted that when precipitation becomes insignificant, the results may turn out to be complex due to the large interaction among plant biomass, runoff and erosion. This may cause increase or decrease the overall erosion.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.5
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• pp.399-407
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• 2009

Laser induced breakdown spectroscopy(LIBS) is an simple analysis method for directly quantifying many kinds of soil micro-elements on site using a small size of laser without pre-treatment at any property of materials(solid, liquid and gas). The purpose of this study were to find an optimum condition of the LIBS measurement including wavelengths for quantifying soil elements, to relate spectral properties to the concentration of soil elements using LIBS as a simultaneous un-breakdown quantitative analysis technology, which can be applied for the safety assessment of agricultural products and precision agriculture, and to compare the results with a standardized chemical analysis method. Soil samples classified as fine-silty, mixed, thermic Typic Hapludalf(Memphis series) from grassland and uplands in Tennessee, USA were collected, crushed, and prepared for further analysis or LIBS measurement. The samples were measured using LIBS ranged from 200 to 600 nm(0.03 nm interval) with a Nd:YAG laser at 532 nm, with a beam energy of 25 mJ per pulse, a pulse width of 5 ns, and a repetition rate of 10 Hz. The optimum wavelength(${\lambda}nm$) of LIBS for estimating soil and plant elements were 308.2 nm for Al, 428.3 nm for Ca, 247.8 nm for T-C, 438.3 nm for Fe, 766.5 nm for K, 85.2 nm for Mg, 330.2 nm for Na, 213.6 nm for P, 180.7 nm for S, 288.2 nm for Si, and 351.9 nm for Ti, respectively. Coefficients of determination($r^2$) of calibration curve using standard reference soil samples for each element from LIBS measurement were ranged from 0.863 to 0.977. In comparison with ICP-AES(Inductively coupled plasma atomic emission spectroscopy) measurement, measurement error in terms of relative standard error were calculated. Silicon dioxide(SiO2) concentration estimated from two methods showed good agreement with -3.5% of relative standard error. The relative standard errors for the other elements were high. It implies that the prediction accuracy is low which might be caused by matrix effect such as particle size and constituent of soils. It is necessary to enhance the measurement and prediction accuracy of LIBS by improving pretreatment process, standard reference soil samples, and measurement method for a reliable quantification method.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1487-1495
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• 2018

In this study, we investigated collagen production and hyaluronic acid production effects for wrinkle improvement test on 50 kinds of land plants and 10 kinds of marine plants native to Jeju Island as a part of developing customized cosmetic materials. Collagen and hyaluronic acid are recognized as major factors affecting skin aging. Cerastium holosteoides var. hallaisanense Mizushima extract ($100{\mu}g/mL$) produced more than 190% of collagen in the extracts of 50 kinds of land plants. Vicia angustifolia var. segetilis K. Koch. extract ($100{\mu}g/mL$) produced more than 160% of collagen. Ftsia japonica Decne. et Planch. extract ($100{\mu}g/mL$), Euonymus japonica Thunb. extract ($100{\mu}g/mL$), Suaeda malacosperma H.Hara extract ($100{\mu}g/mL$), Elaeagnus umbelellata Thunb. extract ($100{\mu}g/mL$), Sedum oryzifolium Makino extract ($100{\mu}g/mL$), Vicia unijuga A. Br. extract ($100{\mu}g/mL$), and Brassica juncea var. integrifolia Sinsk. extract ($100{\mu}g/mL$) showed more than 140% collagen production effect. Among the 10 species of marine plants, Sargassum macrocarpum C. Agardh extract ($50{\mu}g/mL$) produced more than 190% of collagen, and Carpopeltis angusta (Harvey) Okamura extract ($100{\mu}g/mL$), Codiumcoactum Okamura extract ($100{\mu}g/mL$), and Codium tenuifolium S. Shimada, T. Tadano & J. Tanaka extract ($100{\mu}g/mL$) showed more than 140% collagen production. Suaeda malacosperma H.Hara extract ($100{\mu}g/mL$) showed the effect of producing hyaluronic acid more than 140%, and Ftsia japonica Decne. et Planch. extract ($20{\mu}g/mL$) and Wistaria floribunda A.P. DC extract ($100{\mu}g/mL$) showed more than 130% hyalunonic acid production effect. Among the 10 species of marine plants, Peyssonnelia capensis Montagne extract ($100{\mu}g/mL$) was the most effective. Carpopeltis angusta (Harvey) Okamura extract ($100{\mu}g/mL$), Codiumcoactum Okamura extract ($100{\mu}g/mL$), and Codium tenuifolium S. Shimada, T. Tadano & J. Tanaka extract ($100{\mu}g/mL$) showed more than 120% hyalunonic acid production. Jeju resources, which have good collagen and hyaluronic acid production, showed the potential to be applied to solve the skin troubles of customized cosmetics in the future.

• Journal of Applied Biological Chemistry
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• v.61 no.4
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• pp.371-377
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• 2018

The fruits of Panax ginseng were extracted with 80% aqueous MeOH and the concentrates were partitioned into EtOAc, n-BuOH, and $H_2O$ fractions. The repeated $SiO_2$ and octadecyl $SiO_2$ column chromatographies for the EtOAc fraction led to isolation of five ginsenosides. The chemical structures of these compounds were determined as ginsenoside F1 (1), ginsenoside F2 (2), ginsenoside F3 (3), ginsenoside Ia (4), notoginsenoside Fe (5) based on spectroscopic analyses including nuclear magnetic resonance, MS, and infrared. Compounds 2-5 were isolated for the first time from the fruits of P. ginseng in this study. All isolated compounds were evaluated for cytotoxic activities against human cancer cell lines such as HCT-116, SK-OV-3, human cervix adenocarcinoma (HeLa), HepG2, and SK-MEL-5. Among them compounds 2, 4, and 5 showed significant cytotoxicity on cancer cells. Compound 2 exhibited cytotoxicity on SK-MEL-5, HepG2, and HeLa cells with $IC_{50}$ values of 82.8, 86.8, and $78.3{\mu}M$, respectively. Compound 4 showed cytotoxicity on HCT-116, SK-MEL-5, SK-OV-3, HepG2, and HeLa cells with $IC_{50}$ values of 24.5, 25.4, 26.3, 22.0, and $24.9{\mu}M$, respectively. Compound 5 did on SK-MEL-5 cell with $IC_{50}$ value of $81.7{\mu}M$. The cytotoxicity of ginsenoside 2, 4, and 5 isolated from the fruits of Panax ginseng showed strong inhibition effect against on cancer cells, all of which have a glucopyranosyl moiety on C-3.

• Korean Journal of Environmental Agriculture
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• v.38 no.1
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• pp.38-46
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• 2019

BACKGROUND: Salinity is one of the main environmental stresses deteriorating qualities as well as yields of food crops. This study was conducted to identify the effects of salt stress on dry matter ratio, glucose content, and mineral content and composition in potatoes (Solanum tuberosum L.). METHODS AND RESULTS: Four potato varieties were grown in plastic pots (diameter 20 cm and height 25 cm) with three salinity levels (EC: 1.0, 4.0, and 8.0 dS/m) in a glasshouse. Dry matter ratio, specific gravity, starch, and glucose content in tubers harvested at 90 days after sowing were analyzed. Also, mineral contents (T-N, T-C, $P_2O_5$, $K^+$, $Ca^{2+}$, $Mg^{2+}$, $Na^+$) in stem, leaf, and tuber were investigated and statistically analyzed for analysis of variance (ANOVA). Dry matter ratio, specific gravity, and starch content in tubers were reduced in all varieties as the salt concentration increased. Glucose content tended to decrease according to the salt concentration. In ANOVA analysis of mineral contents, there were significant differences in $K^+$ and $Mg^{2+}$ of leaf and stem, in $Na^+$ of leaf and tuber, and also in $Ca^{2+}$ of leaf by the interactions of variety and salinity. In the case of $K^+/Na^+$ and $Ca^{2+}/Na^+$, the stem was more sensitively influenced by the salt treatment than the leaf or the tuber. The $K^+/Na^+$ and $Ca^{2+}/Na^+$ decreased in leaf, stem, and tuber of four varieties, as the salt concentration became higher. The decreasing level varied according to the varieties. 'Kroda' and 'Duback' maintained relatively higher $K^+/Na^+$ and $Ca^{2+}/Na^+$ than 'Atlantic' or 'Goun' under the salt stress conditions. CONCLUSION: The composition and accumulation of minerals in potato plant as well as dry matter ratio, starch, and glucose contents were significantly influenced by salt stress. The respond patterns were different depending on the varieties and it was related to the salt tolerance among varieties.

• Korean Chemical Engineering Research
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• v.60 no.4
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• pp.535-543
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• 2022

A CPFD (Computational particle fluid dynamics) model of solar fluidized bed receiver of silicon carbide (SiC: average d_p=123 ㎛) particles was established, and the model was verified by comparing the simulation and experimental results to analyze the effect of particle behavior on the performance of the receiver. The relationship between the heat-absorbing performance and the particles behavior in the receiver was analyzed by simulating their behavior near bed surface, which is difficult to access experimentally. The CPFD simulation results showed good agreement with the experimental values on the solids holdup and its standard deviation under experimental condition in bed and freeboard regions. The local solid holdups near the bed surface, where particles primarily absorb solar heat energy and transfer it to the inside of the bed, showed a non-uniform distribution with a relatively low value at the center related with the bubble behavior in the bed. The local solid holdup increased the axial and radial non-uniformity in the freeboard region with the gas velocity, which explains well that the increase in the RSD (Relative standard deviation) of pressure drop across the freeboard region is responsible for the loss of solar energy reflected by the entrained particles in the particle receiver. The simulation results of local gas and particle velocities with gas velocity confirmed that the local particle behavior in the fluidized bed are closely related to the bubble behavior characterized by the properties of the Geldart B particles. The temperature difference of the fluidizing gas passing through the receiver per irradiance (∆T/I_DNI) was highly correlated with the RSD of the pressure drop across the bed surface and the freeboard regions. The CPFD simulation results can be used to improve the performance of the particle receiver through local particle behavior analysis.