• Journal of Food Hygiene and Safety
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• v.33 no.2
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• pp.124-130
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• 2018

The Ministry of Food and Drug Safety (MFDS) is amending its test methods for the use of health functional foods (dietary food supplement), in order to establish regulatory standards and specifications in Korea. In this regard, we continue to pursue and perform our research on the analytical method development for the items being researched and reviewed. In this study, we have developed a sensitive and selective test method that could simultaneously separate and determinate six major bioactive flavonolignans in silymarin, which are based on the use of a liquid chromatographic-tandem mass spectrometry (LC-MS/MS). The standard calibration curves presented a linearity effect with the correlation coefficient ($r^2$) > 0.999. The limits of detection (LODs) and limits of quantitation (LOQs) were in the range of $0.3{\sim}9.0{\mu}g/L$ and $0.8{\sim}27.3{\mu}g/L$, respectively. The recovery results ranged between 96.2~98.6% at 3 different concentration levels, and its relative standard deviations (RSDs) were less than 5% as noted in this study. The proposed analytical method was characterized with a noted high resolution of the individual silymarin constituents, and the assay was fully validated as well. Our research can provide a significant scientific evidence that can be useful to amend the silymarin test method for the Health Functional Food Code.

• Food Science of Animal Resources
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• v.30 no.2
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• pp.261-268
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• 2010

This study was conducted to investigate the effects of environmental temperature (ET; $21^{\circ}C$ and $32^{\circ}C$) and antibiotic substitute conditions on meat quality of chicken breast during cold storage. Seven treatments were as follows; T1, ET $21^{\circ}C$ + antibiotics (+); T2, ET $21^{\circ}C$ + antibiotics (-); T3, ET $32^{\circ}C$ + antibiotics (+); T4, ET $32^{\circ}C$ + antibiotics (-); T5, ET $32^{\circ}C$ + 0.1% Lactobacillus; T6, ET $32^{\circ}C$ + 0.1% medicinal plant extract; T7, ET $32^{\circ}C$ + 0.1% essential oil. T7 had a higher (p<0.05) pH at 72 h post-slaughter value when compared to the other treatments. The CIE $b^*$ value of treatments at ET $32^{\circ}C$ showed significantly (p<0.05) higher when compared to the treatments at $21^{\circ}C$. T7 also had significantly (p<0.05) lower TBARS values than the other treatments as the storage time increased. T6 contained significantly (p<0.05) higher extractability of salt-soluble protein contents than the other treatments. The results from SDS-PAGE showed that the actin protein decreased for ET treatments at $32^{\circ}C$. The concentration of actin protein was not significantly different among T1, T2 and T7. Therefore, these result suggested that the antibiotic alternative with essential oil was effective under the high environmental temperature ($32^{\circ}C$) for chicken meat production.

• Food Science of Animal Resources
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• v.30 no.3
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• pp.435-442
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• 2010

The study analyzed the effects of salt concentration [high salt (HS) and low salt (LS)] and sodium nitrite ($NaNO_2$), which are typically utilized in Korean processing facilities, on fatty acid composition, free amino acids, microbial counts and sensory characteristics of processed dry-cured ham. Four different treatments were considered: three hams (11.30 kg) salted with 92 g/kg salt (w/w) (HS), three hams (10.65 kg) treated with HS and 100 ppm $NaNO_2$ (HS+$NaNO_2$), three hams (11.42 kg) salted with 62 g/kg salt (w/w) (LS), and three hams (10.62 kg) treated with LS and 100 ppm $NaNO_2$ (LS+$NaNO_2$). Fatty acid composition analysis revealed significantly (p<0.05) higher saturated fatty acid and lower (p<0.05) unsaturated fatty acid in the HS+$NaNO_2$ group compared with the other groups. Glutamate, alanine and lysine free amino acids were higher than the other free amino acids. The processing conditions did not significantly affect the free amino acids of biceps femoris muscles, except for the proline content (p>0.05). In sensory evaluation, the fermentation aroma of the LS group was higher than that of the HS group. The aerobic counts consistently ranged from from $2.3{\times}10^2$ to $1.11{\times}10^4$ CFU/g. Escherichia coli including strain O157:H7, Staphylococcus aureus, and Salmonella spp. were not detected.

• Economic and Environmental Geology
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• v.22 no.1
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• pp.35-63
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• 1989

Geochemical characteristics of the Guryongsan (Ogcheon) uraniferous black slate show that this is an analogue to the conventional Chattanooga and Alum shales in occurrences. Whereas, its highest enrichment ratio in metals including uranium, among others, is explained by the cyclic sedimentation of the black muds and quartz-rich silts, and the uniform depositional condition with some what higher pH condition compared to the conditions of the known occurrences. The cyclic sedimentation, caused by the periodic open and close of the silled basin, has brought about the flush-out) of the uranium depleted water and the recharge with the new metal-rich sea water, which consequently contributed to the high concentration of metals in mud. The metal-rich marine black muds, which mostly occur in the early to middle Palaeozoic times, is attributed by the geologic conditions which related to the atmospheric oxygen contents, and these are scarcely met in the late Precambrian and/or with the onset of Palaeozoic era in the geologic evolution of the earth.

• Restorative Dentistry and Endodontics
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• v.34 no.4
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• pp.324-332
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• 2009

The purpose of this study was to investigate the effect of rigidity of post core systems on stress distribution by the theoretical technique, finite element stress-analysis method. Three-dimensional finite element models simulating an endodontically treated maxillary central incisor restored with a zirconia ceramic crown were prepared and 1.5 mm ferrule height was provided. Each model contained cortical bone, trabecular bone, periodontal ligament, 4 mm apical root canal filling, and post-and-core. Six combinations of three parallel type post (zirconia ceramic, glass fiber, and stainless steel) and two core (Paracore and Tetric ceram) materials were evaluated, respectively. A 50 N static occlusal load was applied to the palatal surface of the crown with a $60^{\circ}$angle to the long axis of the tooth. The differences in stress transfer characteristics of the models were analyzed. von Mises stresses were chosen for presentation of results and maximum displacement and hydrostatic pressure were also calculated. An increase of the elastic modulus of the post material increased the stress, but shifted the maximum stress location from the dentin surface to the post material. Buccal side of cervical region (junction of core and crown) of the glass fiber post restored tooth was subjected to the highest stress concentration. Maximum von Mises stress in the remaining radicular tooth structure for low elastic modulus resin core (29.21 MPa) was slightly higher than that for high elastic modulus resin core (29.14 MPa) in case of glass fiber post. Maximum displacement of glass fiber post restored tooth was higher than that of zirconia ceramic or stainless steel post restored tooth.

• Current Research on Agriculture and Life Sciences
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• v.5
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• pp.81-88
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• 1987

This study was conducted to determine the contents of heavy metals in Jeotkals (salted-fermented fish and shellfishes) and to investigate the major factor of their contamination. The results were as follows : Average contents of heavy metals in Jeotkals were Hg 0.076 ppm, Pb 0.677 ppm, Cd 0.112ppm, As 1.025ppm, Cu 3.540ppm, Zn 11.230ppm and Mn 2.041ppm, those in fish and shellfishes were Hg 0.051ppm, Pb 0.425ppm, Cd 0.071ppm, As 0.632ppm, Cu 2.ppm, Zn 8.052ppm, Mn 1.178ppm and Hg ND, Pb 0.05ppm, Cd 0.01ppm, As 0.02ppm, Cu 0.087ppm, Zn 0.068ppm and Mn 0.044ppm in salts. During the fermentation of the salted anchovy (Engraulis Japonicus) in each containers, the contents of Hg and Cd had little difference with control, but Pb was high in pottery and iron container and As was in iron and regenerated plastic container. During the fermentation of the salted anchovy in iron container, the contents of heavy metals increased and was to determined more at the later stage of fermentation than at the early stage. Most contents of heavy metals increased in elution experiment of containers, but Hg and Cd did not detected. The concentration of salt did not affect to the elution of heavy metals.

• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.938-946
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• 2017

This study was conducted to examine the changes in serum lipid components and blood glucose by krill (Euphausia superba) meal and sodium fluoride (NaF) in rats fed on experimental diets and administered orally to NaF 10 mg for 5 weeks. Body weight of rats decreased as the amount of krill meal diet increased, it was observed the basal diet plus NaF group (BF group) compared to the lower basal diet group (BD group). The serum concentrations of total cholesterol, LDL (low-density lipoprotein) cholesterol, free cholesterol, triglyceride (TG), phospholipid (PL) and blood glucose in serum were higher in the BF group than the 10% krill meal group plus NaF 10 mg (KF10 group) or BD group, the 20% krill meal plus NaF 10 mg group (KF20 group), the 30% krill meal plus NaF 10 mg group (KF30 group). Conversely depending on the content of krill meal for the HDL (high-density lipoprotein) cholesterol level, it showed higher results. The concentration of total protein was no significant difference among the groups (p<0.05). The results indicate that a krill meal diet effectively inhibited increases in lipid elevation and blood glucose level in the sera of rats.

• Journal of Korean Society of Forest Science
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• v.79 no.4
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• pp.352-358
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• 1990

This study was performed to analyze the pollutants contaminated in the soils and leaves of ornamental trees along the Namhae Express way. The results obtained were as follow ; 1. The contents of total sulfur in soils were generally high in site 8 with slope way and site 9 having more traffic volume, as 87 ppm and 74 ppm, respectively, 2. The contents of heavy metals in soils were lower than those of industrial areas and urban roads, and Fe and Pb contents were higher in sites having much traffic volume. 3. The contents of soluble sulfur in leaves were in the range of 0.08%-0.25%. and those of Pinus strobus and Cedrus deodara were the highest as 0.25% and 0.23%, respectively, and that of Euonymus japonica was 0.08%, the lowest. 4. In the case of heavy metals concentration in leaves, the contents of Fe, Mn, Pb, Zn and Cu were in the range of 68-340 ppm, 101-463 ppm, 2.4-4.9ppm, 33-60 ppm and 1.8-5.1 ppm, respectively. Except Fe, there was not a wide difference between sites and species. 5. In the contents of soluble S, Pb and Zn in leaves, the sites between Jinju and Masan having generally much traffic showed more contents than between Jinju and Hadong. Therefore, it is inferred that contents of S, Pb, and Zn are positive related to the traffic volume. 6. Only for Pb, there was significant correlation between the heavy metals in soils and the leaves at 1% level.

• Journal of the Geological Society of Korea
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• v.54 no.5
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• pp.477-488
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• 2018

Fluid muds commonly occur in estuarine environments, but their ancient examples have rarely been studied in terms of depositional characteristics and processes. Cores of estuarine channel deposits of the Early Cretaceous McMurray Formation, Alberta, Canada show various mudstone layers that possess depositional characteristics of high clay-concentration flows. These mudstone layers are examined in detail through microscopic observation of thin sections and classified into three microfacies (<1 to 25 mm thick) on the basis of sedimentary texture and structures. Structureless mudstone (Microfacies 1) consists mainly of clay particles and contains randomly dispersed coarser grains (coarse silt to fine sand). This microfacies is interpreted as being deposited by cohesive mud flows, i.e., fluid muds, which possessed sufficient strength to support suspended coarser grains (quasi-laminar plug flow). Silt-streaked mudstone (Microfacies 2) mainly comprises mudstone with dispersed coarse grains and includes very thin, discontinuous silt streaks of coarse-silt to very-fine-sand grains. The texture similar to Microfacies 1 indicates that Microfacies 2 was also deposited by cohesive fluid muds. The silt streaks are, however, suggestive of the presence of intermittent weak turbulence under the plug (upper transitional plug flow). Heterolithic laminated mudstone (Microfacies 3) is characterized by alternation of relatively thick silt laminae and much thinner clay laminae. It is either parallel-laminated or low-angle cross-laminated, occasionally showing low-amplitude ripple forms. The heterolithic laminae are interpreted as the results of shear sorting in the basal turbulent zone under a cohesive plug. They may represent low-amplitude bed-waves formed under lower transitional plug flows. These three microfacies reflect a range of flow phases of fluid muds, which change with flow velocities and suspended mud concentrations. The results of this study provide important knowledge to recognize fluid-mud deposits in ancient sequences and to better understand depositional processes of mudstones.

• FLOWER RESEARCH JOURNAL
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• v.17 no.1
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• pp.1-8
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• 2009

This study was conducted to investigate the efficiency of water quality remediation and the inorganic ion removal characteristics by floating plant; water lettuce (Pistia stratiotes L.) in a batch reactor. Water lettuce can be used to remove N and P and other inorganic nutrients, by consuming them in the form of plant nutrient. The highest nutrient absorption of water lettuce was $112.5meL^{-1}\;N$ in Sonneveld-2S, $56.6meL^{-1}\;N$ in Sonneveld-1S, $31.8meL^{-1}\;N$ in sewage and P value was also the highest in Sonneveld-2S as $15.6meL^{-1}$ and in sewage as $5.0meL^{-1}$. These results indicated that using water lettuce held some promise in the context of purification of eutrophication. Also water lettuce had a preference for absorption N. Under Sonneveld-2S treatment, nitrogen percentage was the highest in plant tissue due to the highest concentration of nitrogen and removal by water lettuce. Under sewage, percentage of total N in both plant parts was high. Both above and underground parts, P percentage was less than N. It might be due to the fact that the absorption amount of P was less than N by water lettuce. It meaned that the ability of N removal by water lettuce was higher than that of P, relatively. In summary, these results show that the use of this plant was a viable option.