• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.702-711
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• 2015

This study was conducted to determine the feasibility of using Gastrodia elata Blume as a cosmetic raw material by investigating the physiological activities of its extracts, varying the concentration, solvent, and fermentation method (non-fermentation and fermentation using lactic acid bacteria and effective microorganisms). Of the extracts in three different solvents-water, EtOH, and 70% EtOH-at four different concentrations (0.725, 1.25, 2.5, and 5 mg/mL), the EtOH extracts demonstrated the highest contents of antioxidants (flavonoids, polyphenols, and DPPH free radical scavengers). The DPPH free radical scavenging activity in the EtOH extracts of EM-fermented Gastrodia elata Blume increased from $27.08{\pm}0.5%$ at 1.25 mg/mL to $35.89{\pm}0.8%$ at 2.5 mg/mL. The tyrosinase inhibitory activity test was performed to measure skin-whitening capacity and revealed the LB-fermented EtOH extracts to be the most efficacious ($39.1{\pm}0.4%$ at 0.725 mg/mL, $62.8{\pm}1.5%$ at 2.5 mg/mL). Viability was found to exceed 85% in RAW 264.7 cells treated with all extracts (water, EtOH, 70% EtOH at 10, 25, $50{\mu}L$, fermented and non-fermented), thus proving that Gastrodia elata Blume extracts do not cause inflammation. When RAW 264.7 cells were stimulated with lipopolysaccharide as positive controls under the same conditions to determine the antioxidant activity in the presence of reactive oxygen species (ROS), EM-fermentation was found to impart excellent antioxidant capacity. This study verified the physiological activities of fermented Gastrodia elata Blume extracts that are best suited for cosmetic ingredients, such as antioxidants, tyrosinase inhibitors and anti-inflammatory agents.

• Macromolecular Research
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• v.14 no.4
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• pp.408-415
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• 2006

Temperature-dependent, wide-angle, x-ray diffraction (WAXD) patterns and infrared (IR) spectra were measured for biodegradable poly(3-hydroxybutyrate) (PHB) and its copolymers, poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) P(HB-co-HHx) (HHx=2.5, 3.4, 10.5, and 12 mol%), in order to explore their crystal and lamellar structure and their pattern of C-H...O=C hydrogen bonding. The WAXD patterns showed that the P(HB-co-HHx) copolymers have the same orthorhombic system as PHB. It was found from the temperature-dependent WAXD measurements of PHB and P(HB-co-HHx) that the a lattice parameter is more enlarged than the b lattice parameter during heating and that only the a lattice parameter shows reversibility during both heating and cooling processes. These observations suggest that an interaction occurs along the a axis in PHB and P(HB-co-HHx). This interaction seems to be due to an intermolecular C-H...O=C hydrogen bonding between the C=O group in one helical structure and the $CH_3$ group in the other helical structure. The x-ray crystallographic data of PHB showed that the distance between the O atom of the C=O group in one helical structure and the H atom of one of the three C-H bonds of the $CH_3$ group in the other helix structure is $2.63{\AA}$, which is significantly shorter than the sum of the van der Waals separation ($2.72{\AA}$). This result and the appearance of the $CH_3$ asymmetric stretching band at $3009 cm^{-1}$ suggest that there is a C-H...O=C hydrogen bond between the C=O group and the $CH_3$ group in PHB and P(HB-co-HHx). The temperature-dependent WAXD and IR measurements revealed that the crystallinity of P(HB-co-HHx) (HHx =10.5 and 12 mol%) decreases gradually from a fairly low temperature, while that of PHB and P(HB-co-HHx) (HHx = 2.5 and 3.5 mol%) remains almost unchanged until just below their melting temperatures. It was also shown from our studies that the weakening of the C-H...O = C interaction starts from just above room temperature and proceeds gradually increasing temperature. It seems that the C-H...O=C hydrogen bonding stabilizes the chain holding in the lamellar structure and affects the thermal behaviour of PHB and its copolymers.

• Journal of the Korean Recycled Construction Resources Institute
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• v.1 no.1
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• pp.17-25
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• 2013

Thermal storage technology used for indoor heating and cooling to maintain a constant temperature for a long period of time has an advantage of raising energy use efficiency. This, the phase changing material, which utilizes heat storage properties of the substances, capsulizes substances that melt at a constant temperature. This is applied to construction materials to block or save energy due to heat storage and heat protection during the process in which substances melt or freeze according to the indoor or outdoor temperature. The micro-encapsulation method is used to create thermal storage from phase changing material. This method can be broadly classified in 3 ways: chemical method, physical and chemical method and physical and mechanical method. In the physical and chemical method, a wet process using the micro-encapsulation process utilized. This process emulsifies the core material in a solvent then coats the monomer polymer on the wall of the emulsion to harden it. In this process, a surfactant is utilized to enhance the performance of the emulsion of the core material and the coating of the wall monomer. The performance of the micro-encapsulation, especially the coating thickness of the wall material and the uniformity of the coating, is largely dependent on the characteristics of the surfactant. This research compares the performance of the micro-capsules and heat storage for product according to molecular mass and concentration of the surfactant, SSMA (sulfonated styrene-maleic anhydride), when it comes to micro-encapsulation through interfacial polymerization, in which Dodecan-1 is transformed to melamin resin, a heat storage material using phase changing properties. In addition, the thickness of the micro-encapsulation wall material and residual melamine were reduced by adjusting the concentration of melamin resin microcapsules.

• Journal of Biomedical Engineering Research
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• v.23 no.2
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• pp.147-153
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• 2002

The purpose of this study was to evacuate the effect of different types of Poly(lactic-co-glycolic acid) (PLGA) scaffolds on the formation of human auricular and septal cartilages. All of the scaffolds were formed in a tubular shape for potential application for artificial trachea or esophagus with either 110,000 g/mol PLGA. 220,000 g/mol PLGA. or a combination of both. In order to maintain the tubular shape in vivo, two methods were used. One method was inserting polyethylene tube at the center of scaffolds made of 110,000 g/mol PLGA. The other method involved combination of the two different molecular weight PLGA's. The inner surface of tubular shaped scaffold made with 110,000 g/mol PLGA was coated with 220,000 9/mol PLGA to give more mechanical rigidity. Elastic cartilage was taken from the ear of a patient aged under 20 nears old and hyaline cartilage was taken from the nasal septum. The chondrocytes were then isolated. After second passage, the chondrocytes were seeded on the PLGA scaffolds followed by in vitro culture for one week. The cells-PLGA scaffold complex were implanted subcutaneously on the back of nude mice for 8 weeks. The tissue engineered cartilages were separated from nude mice and examined histologically after staining with the Hematoxylin Eosin. The morphology of the scaffolds were examined by scanning electron microscopy. The pores were well formed and uniformly distributed in the various PLGA scaffolds. After 8 weeks in vivo culture, cartilage was well formed with 110,000 g/mol PLGA. however lumen had collapsed. In contrast. a minimal amount of neocartilage was formed with 220,000 g/mol PLGA, while the architecture of scaffold and lumen were well preserved. Elastic cartilage formed more neocartilage than hyaline. Hyaline and elastic neocartilage were well formed on 110,000 g/mol PLGA with the polyethylene tube, exhibiting mature chondrocytes and preservation of the tubular shape. It was found that 110,000 g/mol PLGA was more appropriate for cartilage formation but higher molecular weight polymer was necessary to maintain the three dimensional shape of the scaffold.

• Journal of the Korean Wood Science and Technology
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• v.11 no.3
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• pp.58-69
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• 1983

This research is performed to compare lignin compounds isolated in Pinus koraiensis Sieb et Zucco, with those compounds which have been already isolated. and to elucidate IR spectra of functional groups and aromatic nucleus for chemical structure of lignin. In vanillin and dehydrodivanillin having carbonyl group ill ${\alpha}$-position. characteristic absorption band of carbonyl group was confirmed in 1665 $cm^{-1}$. Absorption band of vanillic and syringic acid with carboxyl group were indicated in 1675 and 1690 $cm^{-1}$ respectively. Syringic acid showed low wave number because this was affected by methoxyl group. Characteristic absorption bands of guaiacyl, syringly and guaiacyl-syringyl co-polymer nucleus were clearly disclosed in diarylpropane compounds. It were reconfirmed that absorption band of guaiacyl showed longer wave number than of syringly nucleus.

• Applied Chemistry for Engineering
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• v.3 no.4
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• pp.595-604
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• 1992

Carbonate-type polyurethane resins containing anionic moieties were systhesized from NCO-terminated prepolymer method. Membranes were manufactured from the polymer solution and the separation of aqueous ethanol solution was investigated. To enhance the property of urethane resin, carbonate-type polyol(PTMCG) was used. ${\alpha}^{\prime},{\alpha}^{{\prime}{\prime}}$-dimethylolpropionic acid was used as a chain extender to increase the hydrophilicily of the urethane membrane. The ionization of the pendent carboxylic groups in urethane resin was carried out using trimthylamine. To confirm the formation of anionic groups in urethane resin, IR spectra of model compounds were compared with those of urethane resins. It was confirmed that the concentration of hard segment and hydrogen bond contributed to the property of the concentration of hard segment and hydrogen bond contributed to the property of urethane resin in which the mole ratio of chain extender and polyol was from 3:1 to urethane resin in which the mole ratio of chain extender and polyol was from 3:1 to 5:1. The carbonate-type polyurethane containing pendent carboxylic grop(PU) had Tg of around-$25^{\circ}C$ and Tm, $45^{\circ}C$ measured by DSC. Transition temperatures of one containing pendent anionic group(APU) prepared from the ionization of PU shifted to $8{\sim}10^{\circ}C$ lower temperature region than those of PU. Pervaporation membrane was prepared through the casting method. N, N-dimethylformamide (DMF) were used as a solvent and hexamethylene diisocyanate(HMDl) as a crosslinking agent. Swelling degree increased with ethanol concentration in mixure and the control of the swelling degree of the membrane could be achieved by crossliking. The results of pervaporation were as follows : separation factor, 2.3~9.8 ; flux, $27{\sim}79.5g/m^2hr$. Pervaporation separation capacity could be enhanced by reducing the molecular weight of polyol from 2,000 to 1,000.

• Journal of Food Hygiene and Safety
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• v.24 no.4
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• pp.352-356
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• 2009

The purpose of this study was to introduce the toxicological study review to evaluate the safety of PDMS on the 69th JECFA meeting. Polydimethylsiloxane is a polymer and its ADI was established at 23rd JECFA meeting in 1979. The ADI was maintained although the specification was expanded at its 26th, 29 th, 37 th meetings. Recently, it was reported that PDMS with low molecular weight and viscosity has high absorption rate and different toxicity, so it was submitted at 69th meeting. Toxicological studies of PDMS were submitted from the sponsor and additional information is collected from a document searching. The toxicological studies were reviewed in accordance with the 'Guidelines for the preparation of toxicological working papers for the Joint FAO/WHO Expert Committee on Food Additives'. In the available acute, sub-chronic and chronic toxicity studies on PDMS, dose-related increases in incidence and severity of ocular lesions(corneal crystal, inflammation of the corneal epithelium etc.) were consistently observed after oral dosing. It seems to be a local irritant effect, but the mechanism by which the ocular lesions arose is unclear, although the lack of absorption of PDMS indicates that it is unlikely to be a direct systemic effect. Consequently, the relevance of the ocular lesions for food use of PDMS could not be determined. The ADI of PDMS was re-established from 0-1.5 mg/kg bw/day to 0-0.8 mg/kg bw/day by applying additional safety factor 2 based on its ocular toxicity. The result of 0-0.8 mg/kg bw/day is a temporary ADI until further data are provided to 2010.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.6
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• pp.623-634
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• 2014

This study examined a feasibility of coagulation as post-treatment to remove sulfide and phosphorus for the effluent of anaerobic fluidized bed reactor (AFBR) treating domestic wastewater. Removal efficiencies of sulfide, phosphorus and COD by coagulation were not affected by pH in the range of 5.9 to 7.2. Alkalinity requirement could be estimated by the amount of $Fe^{3+}$ to form $Fe(OH)_{3(S)}$ and to remove sulfide and phosphorus. At coagulant aid dosage of 2 mg/L, anionic polymer showed best results regarding size and settleability of flocs. Sulfide removal for the AFBR effluent at the $Fe^{3+}/S^{2-}$ ratio of 0.64, close to the theoretical value of 0.67 found with a synthetic wastewater, was only 75.2%. One of the reasons for this high $Fe^{3+}/S^{2-}$ ratio requirement is that the AFBR effluent contains sulfide, phosphorus, hydroxide and bicarbonate which can react with $Fe^{3+}$ competitively. Concentrations of sulfide and phosphorous reduced to below 0.1 and 0.5 mg/L, respectively, at the $Fe^{3+}/S^{2-}$ ratio of 2.0. Average effluent COD of 80 mg/L, mostly soluble COD, was obtained at the dosage 50 mg $Fe^{3+}/L$ ($Fe^{3+}/S^{2-}$ ratio of 2.0) with corresponding COD removal of 55%. For better removal of COD, soluble COD removal at the AFBR should be enhanced. Coagulation with $Fe^{3+}$ removed sulfide, phosphorus and COD simultaneously in the AFBR effluent, and thus could be an alternative process for the conventional wastewater treatment processes where relatively high quality effluent is not required.

• Journal of Food Hygiene and Safety
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• v.32 no.5
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• pp.424-433
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• 2017

Antioxidants are used in the manufacturing of commercial food packages made of polyolefin plastic such as polyethylene and polypropylene for the purpose to delay the oxidation reaction of the polymer due to oxygen or traces of ozone in the atmosphere. Additives in plastics may be migrated from the packaging materials into foods, thereby presenting a potential health risk to the consumer. Therefore, it is necessary to determine migration level of antioxidants from food packaging materials to foodstuffs in order to take proactive management. In this study, we have developed a method for the analysis of 10 antioxidants, which are butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), Cyanox 2246, 425 and 1790, Irgafos 168, and Irganox 1010, 1330, 3114 and 1076, migrated from the food packaging materials into four food simulants for aqueous, acidic, alcoholic and fatty foods. The antioxidants were determined by reversed-phase high-performance liquid chromatograph-ultraviolet detector with 276 nm after solid-phase extraction with a hydrophilic-lipophilic balance (HLB) cartridge or dilution with isopropanol. The analytical method showed a good linearity of coefficient ($R^2{\geq}0.99$), limits of detection (0.11~0.41 mg/L), and limits of quantification (0.34~1.24 mg/L). The recoveries of antioxidants spiked to four food simulants ranged from 71.3% to 109.4%. The migrated antioxidants in this study were within the safety levels that resulted from the safety assessment by the estimated daily intake to the tolerable daily intake.

• Journal of Food Hygiene and Safety
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• v.32 no.5
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• pp.434-442
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• 2017

The UV light in sunlight breaks down the chemical bonds in a polyolefin polymer through a process called photodegradation, ultimately causing cracking, chalking, colour changes, and loss of physical properties such as impact strength, tensile strength, elongation, and others. UV absorbers are used to prevent or terminate the oxidation of plastics by UV light. They are receptive to UV radiation and dissipate the energy harmlessly as heat. Benzotriazoles and benzophenones are used mainly in polyolefins such as polyethylene and polypropylene. In this study, we have developed a method for the analysis of 12 UV absorbers, which are Uvinul 3000, Cyasorb UV 24, Uvinul 3040, Tinuvin 312 and P, Seesorb 202, Chimassorb 81, Tinuvin 329, 234, 326, 328 and 327, migrated from the food packaging materials into four food simulants for aqueous, acidic, alcoholic and fatty foods. The UV absorbers in food simulants were determined by reversed-phase high performance liquid chromatograph-ultraviolet detector with 310 nm after solid-phase extraction with a hydrophilic-lipophilic balance (HLB) cartridge or dilution with isopropanol. The analytical method showed a good linearity of coefficient ($R^2{\geq}0.99$), limits of detection (0.049~0.370 mg/L), and limits of quantification (0.149~1.120 mg/L). The recoveries of UV absorbers spiked to four food simulants ranged from 70.05% to 110.13%. The developed method would be used as a reliable tool to determine concentrations of the migrated UV absorbers.