• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.1
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• pp.57-64
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• 2016

Just like UV radiation, heat increases collagen degradation and accumulation of abnormal elastin fiber and this is termed thermal skin aging. Dunaliella salina (DS), a green alga, is known for its beta-carotene accumulation, having various applications in the health and nutritional products. However, the effects of DS on heat-induced skin aging remain unexplored. In this study, we performed anti-thermal aging tests of the ethanol extract of DS (DSE). We measured the cellular levels of type I procollagen and MMP-1 using ELISA in human dermal fibroblast cells after heat shock. DSE reduced the expression of MMP-1 protein and increased the expression of type I procollagen. In addition, DSE upregulated the mRNA expression of HSP47 reduced by heat shock, which is involved in collagen synthesis. Also, DSE reduced the expression of inflammation mediator (TGF-${\beta}$, IL-12, etc). We demonstrate that DSE regulates the heat-induced solar elastosis through the regulation of tropoelastin and fibrillin-1, two major proteins of elastic fibers, and MMP-12 expression. These results suggest that DSE may be effective for preventing thermally induced skin aging.

• Applied Chemistry for Engineering
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• v.25 no.5
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• pp.510-514
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• 2014

In this work, the effect of torrefaction on the basic characteristic of sewage sludge was studied to evaluate the energy potential as a solid fuel. Torrefaction experiments were performed at temperatures of $150{\sim}600^{\circ}C$. The torrefied sewage sludge was characterized by the energy yield, ash content, volatile fraction and high heating value (HHV). The gaseous products from torrefaction of the sewage sludge were also analyzed. Thermogravimetric analysis was carried out for the kinetic analysis of sewage sludge torrefaction. From this work, it was found that the ash content increased with an increase of the torrefaction temperature while the energy yield, HHV and volatile fraction decreased. It was also found that the emission of carbon monoxide and hydrocarbon gases started at $300^{\circ}C$ by the thermal degradation of volatile components in the sewage sludge.

• Korean Journal of Environmental Agriculture
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• v.29 no.2
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• pp.165-175
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• 2010

A gas chromatographic (GC) method was developed to determine residues of captan, folpet, captafol, and chlorothalonil, known as broad-spectrum protective fungicides for the official purpose. All the fungicide residues were extracted with acetone containing 3% phosphoric acid from representative samples of five agricultural products which comprised rice, soybean, apple, pepper, and cabbage. The extract was diluted with saline, and dichloromethane partition was followed to recover the fungicides from the aqueous phase. Florisil column chromatography was additionally employed for final cleanup of the extracts. The analytes were then determined by gas chromatography using a DB-1 capillary column with electron capture detection. Reproducibility in quantitation was largely enhanced by minimization of adsorption or thermal degradation of analytes during GLC analysis. Mean recoveries generated from each crop sample fortified at two levels in triplicate ranged from 89.0~113.7%. Relative standard deviations (RSD) were all less than 10%, irrespective sample types and fortification levels. As no interference was found in any samples, limit of quantitation (LOQ) was estimated to be 0.008 mg/kg for the analytes except showing higher sensitivity of 0.002 mg/kg for chlorothalonil. GC/Mass spectrometric method using selected-ion monitoring technique was also provided to confirm the suspected residues. The proposed method was reproducible and sensitive enough to determine the residues of captan, folpet, captafol, and chlorothalonil in agricultural commodities for routine analysis.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.5
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• pp.732-742
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• 2013

Flavour comprises mainly of taste and aroma and is involved in consumers' meat-buying behavior and preferences. Chicken meat flavour is supposed to be affected by a number of ante- and post-mortem factors, including breed, diet, post-mortem ageing, method of cooking, etc. Additionally, chicken meat is more susceptible to quality deterioration mainly due to lipid oxidation with resulting off-flavours. Therefore, the intent of this paper is to highlight the mechanisms and chemical compounds responsible for chicken meat flavour and off-flavour development to help producers in producing the most flavourful and consistent product possible. Chicken meat flavour is thermally derived and the Maillard reaction, thermal degradation of lipids, and interaction between these 2 reactions are mainly responsible for the generation of flavour and aroma compounds. The reaction of cysteine and sugar can lead to characteristic meat flavour specially for chicken and pork. Volatile compounds including 2-methyl-3-furanthiol, 2-furfurylthiol, methionol, 2,4,5-trimethyl-thiazole, nonanol, 2-trans-nonenal, and other compounds have been identified as important for the flavour of chicken. However 2-methyl-3-furanthiol is considered as the most vital chemical compound for chicken flavour development. In addition, a large number of heterocyclic compounds are formed when higher temperature and low moisture conditions are used during certain cooking methods of chicken meat such as roasting, grilling, frying or pressure cooking compared to boiled chicken meat. Major volatile compounds responsible for fried chicken are 3,5-dimethyl-1,2,4-trithiolanes, 2,4,6-trimethylperhydro-1,3,5-dithiazines, 3,5-diisobutyl-1,2,4-trithiolane, 3-methyl-5-butyl-1,2,4-trithiolane, 3-methyl-5-pentyl-1,2,4-trithiolane, 2,4-decadienal and trans-4,5-epoxy-trans-2-decenal. Alkylpyrazines were reported in the flavours of fried chicken and roasted chicken but not in chicken broth. The main reason for flavour deterioration and formation of undesirable "warmed over flavour" in chicken meat products are supposed to be the lack of ${\alpha}$-tocopherol in chicken meat.

• Korean Journal of Environmental Agriculture
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• v.12 no.2
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• pp.176-183
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• 1993

Photolysis experiments were conducted to investigate the stability of a new insecticide, [O,O-Diethyl O-(1-phenyl-3-trifluoromethyl-5-pyrazoyl) thiophosphoric acid ester: KH-502] under the various conditions. In the photolysis experiment, KH-502 was, after being added into the acetone or acetonitrile solution, irradiated under the sunlight or UV lamp $(300{\sim}350nm)$, where acetone or acetonitrile solution was varied with water and $O_2$contents and was treated with humic acid, rosebengal or tryptophan. Results for stability and degradation pattern of KH-502 from the above experiment can be summarized as follows: 1. The significant difference in KH-502 decomposition due to photolysis was shown for between KH-502s irradiated at $300{\sim}350$ nm and non-irradiated. KH-502 was photolyzed in the acetone by the sensitizing effect, but was stable in the acetonitrile. 2. The degradation pattern of KH-502 in the photolysis was different as compared to that in the thermal decomposition, and the decomposed products were O,O-Diethyl O-(1-phenyl-3-trifluoromethyl-5-pyrazoyl)phosphoric acid ester (KH-502 oxo form), O,S-Diethyl O-(1-phenyl-3-trifluoromethyl-5-pyrazoyl)phosphorothiolate(S-ethyl KH-502), 1-Phenyl-3-trifluoromethyl-5-hydroxy pyrazole (PTMHP) and several unknown compounds. 3. Treatments of acetone or acetonitrile solution with humic acid, rosebengal or tryptophan revealed no-sensitizing effect on the photolysis of KH-502. Dissolved oxygen in the acetone played as a cosensitizer with acetone competitively to enhance the photolysis of KH-502. 4. Treatments of acetone with humic acid or paddy soil water collected from fields decreased the photolysis of KH-502.

• Korean Chemical Engineering Research
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• v.48 no.2
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• pp.259-267
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• 2010

The catalytic wet oxidations of the wastewater containing azo dye Reactive Black 5(RB5) with heterogeneous catalyst of CuO have been carried out to investigate the effects of temperature($190{\sim}230^{\circ}C$) and catalyst concentration(0.00~0.20 g/l) on the removals of colour and total organic carbon TOC. The wastewater colour was measured with spectrophotometer, and the oxidation rate was estimated with TOC. About 90% of colour was removed during 120 min in thermal degradation of the RB5 wastewater at $230^{\circ}C$, while TOC was not removed at all. As increasing reaction temperature and catalyst concentration, the removal rates of colour and TOC increased in the catalytic wet oxidations of RB5 wastewater. The effects of catalyst were already considerable even at 0.01 g CuO/l, while the removal rates of colour and TOC increased negligibly with increasing the catalyst concentration above 0.05 g CuO/l. The initial destruction rates of the wastewater colour have shown the first-order kinetics with respect to the wastewater colour. TOC changes during catalytic wet oxidations have been well described with the global model, in which the easily degradable TOC was distinguished from non-degradable TOC of the wastewater. The impacts of reaction temperature on the destruction rate of the wastewater colour and TOC could be described with Arrhenius relationship. Activation energies of the colour removal reaction in thermal degradation, wet oxidation, and catalytic wet oxidation(0.20 g CuO/l) of the RB5 wastewater were 108.4, 78.3 and 74.1 kJ/mol, respectively. The selectivity of wastewater TOC into the non-degradable intermediates relative to the end products in the catalytic wet oxidations of RB5 wastewater was higher compared to that in phenol wet oxidations.

• Resources Recycling
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• v.16 no.3 s.77
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• pp.19-26
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• 2007

The bottom ash of municipal solid waste incineration generated during incineration of municipal solid waste in metropolitan area consists of ceramics, glasses, ferrous materials, combustible materials and food waste and so on. Although the ferrous material was separated by the magnetic separation before the incineration process, of which content accounts for about $3{\sim}11%$ in bottom ash. The formation of a $Fe_3O_4-Fe_2O_3$ double layer(similar to pure Fe) on the iron surface was found during air-annealing in the incinerator at $1000^{\circ}C$. A strong thermal shock, such as that takes place during water-cooling of bottom ash, leads to the breakdown of this oxidation layer, facilitating the degradation of ferrous metals and the formation of corrosion products and it existed as $Fe_2O_3,\;Fe_3O_4\;and\;FeS_2$. So, many problems could occur in the use of bottom ash as an aggregate substitutes in construction field. Therefore, in this study, the separation of ferrous materials from municipal solid waste incineration bottom ash was investigated. In the result, the ferrous product(such as $Fe_2O_3,\;Fe_3O_4,\;FeS_2$ and iron) by magnetic separator at 3800 gauss per total bottom ash(w/w.%) accounted for about 18.7%, and 87.7% of the ferrous product was in the size over 1.18 mm. Also the iron per total bottom ash accounted for about 3.8% and the majority of it was in the size over 1.18 mm.