• Korean Journal of Food Science and Technology
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• v.51 no.5
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• pp.480-485
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• 2019

The present study was conducted to compare antioxidant capacities of protein hydrolysates from four different edible insects (Protaetia brevitarsis larvae, Allomyrina dichotoma larvae, Gryllus bimaculatus imago, and Tenebrio molitor larvae) which have recently been registered as food varieties in Korea. Protein hydrolysates were prepared from each insect using enzymatic hydrolysis using alcalase, and were then separated into a fraction containing ${\leq}3kDa$. According to $RC_{50}$ values and trolox equivalent antioxidant capacity results obtained from five different antioxidant analyses, the Gryllus bimaculatus (GB) hydrolysate showed relatively high levels of antioxidant capacity and, in particular, the GB hydrolysate showed considerably strong antioxidant activities in 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and in ferric reducing antioxidant power (FRAP) assays. The GB hydrolysate also showed the strongest inhibitory effect on peroxidation of linoleic acid, and its rate of inhibition at $100{\mu}g/mL$ on day 3 of treatment was 60.26%. These results suggest that protein hydrolysates from edible insects including GB represent potential sources of natural antioxidants.

• Journal of the Mineralogical Society of Korea
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• v.32 no.3
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• pp.163-172
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• 2019

A long core (RS15-LC48) was collected at a site in the continental rise between the Southern Ocean and the Ross Sea (Antarctica) during the 2015 Ross Sea Expedition. The mineralogical characteristics and the origin of clay minerals in marine sediments deposited during the Quaternary in the Ross Sea were determined by analyzing sedimentary facies, variations in grain size, sand fraction, mineralogy, clay mineral composition, illite crystallinity, and illite chemical index. Core sediments consisted mostly of sandy clay, silty clay, or ice rafted debris (IRD) and were divided into four sedimentary facies (units 1-4). The variations in grain size distribution and sand content with depth were very similar to the variations in magnetic susceptibility. Various minerals such as smectite, chlorite, illite, kaolinite, quartz, and plagioclase were detected throughout the core. The average clay mineral composition was dominated by illite (52.7 %) and smectite (27.7 %), with less abundant clay minerals of chlorite (11.0 %) and kaolinite (8.6 %). The IC and illite chemical index showed strong correlation trends with depth. The increase in illite and chlorite content during the glacial period, together with the IC and chemical index values, suggest that sediments were transported from the bedrocks of the Transantarctic Mountains. During the interglacial period, smectite may have been supplied by the surface current from Victoria Land, in the western Ross Sea. High values for IC and the illite chemical index also indicate relatively warm climate conditions during that period.

• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.864-873
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• 1995

Amorphous $Fe_{73.5}Cu_{1}Nb_{3}Si_{16.5}B_{6}$ ribbons were annealed for different time at $500^{\circ}C$ and $552^{\circ}C$, just before and after the exothermic reaction in DSC curve. The development of nanocrystalline phase was investigated by means of $M\"{o}ssbsuer$ spectroscopy. The crystalline phase consists mainly of $DO_{3}Fe-Si$. Though slight in amount (5%), another ferromagnetic phase which could be presumed $t-Fe_{3}B$ was detected Si content of $DO_{3}Fe-Si$, Si/(Fe+Si), was 0.218 under the heat treatment at $500^{\circ}C$ for 60 min and 0.222 at $552^{\circ}C$ for 10 min. Since then both of those values decreased with time until 120 min and finally these two values remained constant at 0.210. The variation in Si content with annealing time results in the variation in the hyperfine field and the isomer shift. The increase in the mean hyperfine fields and the decrease in the mean isomer shifts of Fe-Si are caused by the increase in Si content. The volume fractions of residual amorphous phase rapidly decrease during the early stage of annealing and come nearer to saturation after 120 min both at $500^{\circ}C$ and $552^{\circ}C$. The decrease in the mean hyperfine field of residual amorphous. in spite of slight changes in the volume fractions of Fe-Si and of residual amorphous after 120 min. is caused by the increase in the content of Nb and B in residual amorphous phase. The saturated volume fraction of the crystalline phase was 81% for $500^{\circ}C$ (180 min) and 77% for $552^{\circ}C$ (960 min), different from expectation.

• Food Science and Preservation
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• v.11 no.1
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• pp.79-87
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• 2004

To investigate antioxidative effects of phenolic compounds separated from persimmon leaves(PL)(Diospyros kaki Thunb.) on the ethanol-induced hepatotoxicity in rat, Sprague-Dawley rats weighing 100-150 g were divided into 5 groups; control group(CON), PL(70 mg/kg) administered group(PEl), ethanol(5 mL/kg, 25％) administered group(ETH), PL(70 mg/kg) and ethanol administered group (PE2), and PL(140 mg/kg) and ethanol administered group(PE3), respectively. The antioxidative activity of persimmon leaves decreased in order of ethylacetate>interphase materials>n-butanol>chloroform>n-hexane>water fraction. The growth rate and feed efficiency ratio decreased by ethanol were gradually increased to the adjacent level of CON by administering PL. The serum activities of ALT, alkaline phosphatase and lactic acid dehydrogenase elevated by ethanol were decreased significantly. It was also observed that the activities of SOD, catalase, and GSH-Px of rat liver increased by ethanol were markedly decreased in PL administered group as compared to ETH. The GSH content of liver was decreased by ethanol, but that was increased in PE1 and PE2 compared with ETH as a dose-dependant manner. These results suggested that phenolic compounds separated from persimmon leaves have a possible protective and relievable effect on the ethanol-induced hepatotoxicity in rats.

• Korean Journal of Plant Resources
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• v.28 no.2
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• pp.145-152
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• 2015

The present study aimed to investigate comparative anti-inflammatory effects of Litsea japonica fruit and leaf extract considering the balance of safety and efficacy. Dose response studies were performed to determine the inhibitory effects of 70% EtOH extract of leaf (L70%) on the pro-inflammatory enzymes expression, COX-2/PGE2 and NO/iNOS, and pro-inflammatory cytokines production, IL-$1{\beta}$, IL-6, and TNF-$\alpha$ in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. We also examined comparative effects of 30 and 70% EtOH extract of fruits (F30% and F70%) at low concentration ($10{\mu}g/ml$ ) in the same conditions. L70% at 50 and $100{\mu}g/ml$ showed inhibitory effects on almost all the inflammatory mediators we examined except for COX-2 regulation, but there were no effects at $10{\mu}g/ml$. Since $100{\mu}g/ml$ of L70% have 18.2% cytotoxicity, we compared the effects of fruit extract, F30% and F70% at $10{\mu}g/ml$ on the regulation of NO/iNOS, PGE2, IL-$1{\beta}$, IL-6, and TNF-$\alpha$ and obtained that fruit extacts are more efficacious and safe than leaf. This study suggests that the 30% EtOH fraction of L. japonica fruit could be a good candidate for development as a functional food supplement in the prevention of inflammatory disorders.

• Korean Journal of Plant Resources
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• v.31 no.4
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• pp.303-311
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• 2018

In this study, a preliminary evaluation of the antioxidant and anti-inflammatory activity of the Ficus erecta var. sieboldii (Miq.) King (FES) leaf extract has been performed to assess its potential as a natural resource for food and medicinal materials. FES was extracted using 70% EtOH and then fractionated sequentially using n-hexane, $CH_2Cl_2$, EtOAc, and n-BuOH. To screen for antioxidant and anti-inflammatory agents effectively, the inhibitory effect of the FES extracts on the production of oxidant stresses (DPPH, xanthine oxidase, and superoxide) and pro-inflammatory factors (NO, iNOS, COX-2, $PGE_2$, IL-6, and $IL-1{\beta}$) in the murine macrophage cell line RAW 264.7 activated with lipopolysaccharide (LPS) was examined. Among the sequential solvent fractions of FES, the $CH_2Cl_2$ and EtOAc fractions showed decreased production of oxidant stresses (DPPH, xanthine oxidase and superoxide), and the hexane and $CH_2Cl_2$ fractions of FES inhibited the production of pro-inflammatory factors (NO, iNOS, COX-2, and $PGE_2$). The $CH_2Cl_2$ fraction also inhibited the production of pro-inflammatory cytokines ($TNF-{\alpha}$, IL-6, and $IL-1{\beta}$). These results suggest that FES has a significant effects on the production of oxidant stresses and pro-inflammatory factors and may be used a natural resource for antioxidant and anti-inflammatory agents.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.4
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• pp.307-314
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• 1989

Barley, garlic, and soybean were cultivated in the silt loam, sandy loam, and loam, respectively, and the absorbing patterns of N, P, and K during growing of the crops were determined. While, the leaching of N, P, and K applied in the above soils in four levels of topsoil depths and in four leachate levels of excess precipitation was measured through the column. The depths of the soil were devised to 20, 35, 50, and 65cm, and the levels of excess water were classified to each leachate of 20, 40, 60, and 80mm precipitation, and nitrogen, phosphorous, and potassium in each fraction of the leachate were analyzed. By the analyses of the chemical components during growth of the crops, their absorbing patterns of N, P, and K were investigated. The order of N-leachings in the soils was sandy loam > loam > silt loam, and the leaching of $K_2O$ was very similar to N. The leaching of $P_2O_5$ was slight in all kinds of the soils. By the combination of the absorbing patterns of the crops in three kinds of soils and the leaching of the nitrogen in four levels of soil depth and four levels of excess precipitation, the method to replace the nitrogen lost by leaching was presented.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.5
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• pp.385-392
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• 2009

This study was conducted to reclassify Namweon series, black volcanic ash soils, in Jeju Island based on the second edition of Soil Taxonomy : A Basic System of Soil Classification for Making and Interpreting Soil Surveys. Morphological properties of typifying pedon of Namweon series were investigated and physicochemical properties were analyzed according to Soil Survey Laboratory Methods Manual. The typifying pedon of Namweon series has black (10YR 2/1) silt loam Ap horizon (0~11 cm) and black (10YR 2/1) silt loam BA horizon (11~72 cm). Bw horizon (72~100 cm) is very dark brown (10YR 2/2) silt loam. That occurs on lava plain derived from volcanic ash materials. The typifying pedon contains 5.2~6.4% oxalate extractable (Al + 1/2 Fe), over 85% phosphate retention, and lower bulk density than $0.90Mg\;m^{-3}$. Ap, BA, and Bw horizons of the pedon have andic soil properties. That can be classified as Andisol. The typifying pedon has an udic soil moisture regime and has a 1,500 kPa water retention of 15% or more on air-dried samples throughout all horizons, and can be classified as Udand. Ap and BA horizons (0~72 cm) have a color value, moist, and chroma of 2 or less, melanic index of 1.70 or less, and 6% or more organic carbon. That meets the requirements of melanic epipedon. That keys out as Melanudand. That has more than 6.0% organic carbon and the colors of mollic epipedon throughout a layer 50 cm or more thick within 60 cm of the mineral soil surface.. Thus, that keys out as Pachic Melanudand. The pedon has a fine-earth fraction that has a water content at 1,500 kPa tension of 12% or more on air-dried samples and has less than 35% (by volume) rock fragments. Thus, the substitute for particle-size class is medial. That has a sum of 8 times the Si (percnt by weight extracted by acid oxalate) plus 2 times the Fe (percnt by weight extracted by acid oxalate) of 5 or more, and 2 times the Fe is more than 8 times the Si. Thus, the mineralogy class is ferrihydritic. Namweon series can be classified as medial, ferrihydritic, thermic family of Pachic Melanudands, not as ashy, thermic family of Typic Melanudands.

• Korean Journal of Mineralogy and Petrology
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• v.34 no.3
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• pp.157-167
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• 2021

Lead (Pb) is one of the key trace elements, exhibiting a peculiar partitioning behavior into silicate melts in contact with minerals. Partitioning behaviors of Pb between silicate mineral and melt have been known to depend on melt composition and thus, the atomic structures of corresponding silicate liquids. Despite the importance, detailed structural studies of Pb-bearing silicate melts are still lacking due to experimental difficulties. Here, we explored the effect of lead content on the atomic structures, particularly the evolution of silicate networks in Pb-bearing sodium metasilicate ([(PbO)_x(Na₂O)_1-x]·SiO₂) glasses as a model system for trace metal bearing natural silicate melts, using ²⁹Si solid-state nuclear magnetic resonance (NMR) spectroscopy. As the PbO content increases, the ²⁹Si peak widths increase, and the maximum peak positions shift from -76.2, -77.8, -80.3, -81.5, -84.6, to -87.7 ppm with increasing PbO contents of 0, 0.25, 0.5, 0.67, 0.86, and 1, respectively. The ²⁹Si MAS NMR spectra for the glasses were simulated with Gaussian functions for Qⁿ species (SiO₄ tetrahedra with n BOs) for providing quantitative resolution. The simulation results reveal the evolution of each Qⁿ species with varying PbO content. Na-endmember Na₂SiO₃ glass consists of predominant Q² species together with equal proportions of Q¹ and Q³. As Pb replaces Na, the fraction of Q² species tends to decrease, while those for Q¹ and Q³ species increase indicating an increase in disproportionation among Qⁿ species. Simulation results on the ²⁹Si NMR spectrum showed increases in structural disorder and chemical disorder as evidenced by an increase in disproportionation factor with an increase in average cation field strengths of the network modifying cations. Changes in the topological and configurational disorder of the model silicate melt by Pb imply an intrinsic origin of macroscopic properties such as element partitioning behavior.

• Korean Journal of Food Science and Technology
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• v.53 no.4
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• pp.423-433
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• 2021

This study was performed to examine the neuroprotective effect of the ethyl acetate fraction from Eucommia ulmoides oliver leaf (EFEL) on PM_2.5-induced cytotoxicity. EFEL had higher total phenolic and flavonoid contents than the other fractions. In ABTS and DPPH radical scavenging activities, the IC₅₀ of EFEL was measured as 212.80 and 359.13 ㎍/mL, respectively. To investigate the neuroprotective effect of EFEL, MTT and DCF-DA assays were performed on HT22, MC-IXC, and BV-2 cells. EFEL effectively decreased PM_2.5-induced intercellular reactive oxygen species (ROS) content and inhibited PM_2.5-induced cell death. In the results of protein expression related to cellular cytotoxicity on microglial cells (BV-2), EFEL had an improvement effect on cell apoptosis and inflammatory pathways. Rutin and chlorogenic acid were identified as the main physiological compounds. Moreover, it was expected that EFEL, including rutin and chlorogenic acid, could be functional food substances with neuroprotective effects against PM_2.5-induced oxidative stress.