• 한국수산과학회지
• /
• 제54권2호
• /
• pp.218-223
• /
• 2021

In this study, the possibility of use as a cartridge for 3D printing was confirmed by adding calcium to the alginic acid-added surimi mixture. The Alaska pollack Gadus chalcogrammus surimi added with alginic acid was immersed in a calcium solution (1 M calcium carbonate, 1 M calcium chloride, 1 M calcium sulfate, and 0.1 M calcium lactate) to evaluate the physical properties, color differences, and sensory properties of Alaska pollack surimi according to calcium types. As the results, in the case of surimi paste to which 1 M calcium carbonate was added, physical properties were weaker than that of 1 M calcium chloride, but gelation was appropriate and sensory properties was excellent. Addition of 1 M calcium chloride has the best physical properties, but it has a problem of bitter taste. With the addition of 1 M calcium sulfate, it has low solubility and poor physical properties as well as poor elasticity and bad taste. Addition of 0.1 M calcium lactate has weak physical properties but good sensory properties. From these results, 1 M calcium chloride has the best physical properties, but there is a decisive problem in sensory properties, so 1 M calcium carbonate is most suitable for commercial use.

• Journal of Microbiology and Biotechnology
• /
• 제15권4호
• /
• pp.815-822
• /
• 2005

In order to extend the shelf-life of packaged or coated foods, an antibacterial edible film was developed from soybean meal that had been fermented with Bacillus subtilis under the optimum condition of pH 7.0-7.5 and $33^{\circ}C$ for 33 h. The water vapor permeability of the fermented film ($86.0 mg/cm^2{\cdot}h$) was higher than those of normal soybean films ($66.9 mg/cm^2{\cdot}h$). Protein solubility of the fermented film was also higher than ordinary soy protein film at the pH range of 3 -10. The fermented soybean film had higher tensile strength and lower $\%$ elongation (elongation rate) than the ordinary soybean film, mainly because partial hydrolysis of proteins in the soybean film occurred during fermentation. Antimicrobial properties of the fermented film on foodstuffs were measured by placing the films on surime, jerked beef, and mashed sausage media; containing $10^2-10^3$ CFU/plate of foodborne pathogenic bacteria, and showed significantly higher inhibitory effects on the growths of all the indicating bacteria. The film could be used as a packaging material in the food industry. However, before direct application of the fermented film to the commercial food industry, its poor mechanical and antibacterial properties need to be improved.

• Elastomers and Composites
• /
• 제36권4호
• /
• pp.268-277
• /
• 2001

PPG, PEG, trimethylolpropane(TMP) 등의 폴리올에 MDI(4,4'-diphenyl methane diisocyanate)를 각각 혼합하고 경화시켜 여러가지 물성을 측정하였다. 경화시간은 PEG와 TMP의 함량이 늘어날수록 짧게 나타났고 분자량의 효과보다는 관능기의 수에 더 큰 영향을 받았다. NCO-OH 반응은 NCO-NCO반응보다 활성적이고 빠르게 일어났다. 경도는 가교밀도와 분자구조의 영향을 받았으며 NCO-NCO 반응으로 생긴 도막은 취약하였고 NCO-OH간의 반응으로 생긴 도막은 유연하였다. 부착력은 결정화도와 수축율이 클수록 낮은 값을 나타내었으며 TMP 함량이 증량될수록 높은 값을 나타내었다. 난연성은 난연제의 종류와 함량에 영향을 받았으며 난연효과는 IXOL B-251이 가장 우수하였고 TCCP는 수지와의 상용성이 좋지 않아 부분적으로 분리되었다.

• 대한화학회지
• /
• 제54권6호
• /
• pp.761-765
• /
• 2010

Poly (N,N-dimethylacrylamide)는 수용성과 생체적합성이 뛰어나 다양한 분야에서 매우 유용하게 사용되고 있다. 본 연구는 N,N-dimethylacrylamide를 교차결합제인 EGDMA (ethylene glycol dimethacrylate)와 HEMA (2-hydroxyethyl methacrylate), MMA (methyl methacrylate), NVP (N-vinyl-2-pyrrolidone) 그리고 개시제인 AIBN (azobisisobutyronitrile)과 함께 공중합 하였다. 생성된 고분자의 물리적 특성을 측정한 결과, 함수율 36 - 42%, 굴절률 1.433 - 1.426, 가시광선 투과율 90 - 91%, 산소전달율 13.1 - $21.29{\times}10^{-11}(cm^2/sec)$ ($mlO_2/mL{\times}mmHg$) 범위의 분포를 나타내었다. 또한 polarographic method에 의한 공중합체의 산소전달율을 측정한 결과 N,N-dimethylacrylamide의 함량이 증가할수록 11.0% - 80.5% 증가한 결과를 보였다. 본 실험결과로 볼 때 생성된 공중합체는 고산소투과성을 지닌 하이드로젤 렌즈 재료로 사용될 수 있을 것으로 판단된다.

• Preventive Nutrition and Food Science
• /
• 제21권3호
• /
• pp.271-280
• /
• 2016

The effects of $CO_2$ injection and barrel temperatures on the physiochemical and antioxidant properties of extruded cereals (sorghum, barley, oats, and millet) were studied. Extrusion was carried out using a twin-screw extruder at different barrel temperatures (80, 110, and $140^{\circ}C$), $CO_2$ injection (0 and 500 mL/min), screw speed of 200 rpm, and moisture content of 25%. Extrusion significantly increased the total flavonoid content (TFC) of extruded oats, and ${\beta}$-glucan and protein digestibility (PD) of extruded barley and oats. In contrast, there were significant reductions in 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, PD of extruded sorghum and millet, as well as resistant starch (RS) of extruded sorghum and barley, and total phenolic content (TPC) of all extrudates, except extruded millet. At a barrel temperature of $140^{\circ}C$, TPC in extruded barley was significantly increased, and there was also an increase in DPPH and PD in extruded millet with or without $CO_2$ injection. In contrast, at a barrel temperature of $140^{\circ}C$, the TPC of extruded sorghum decreased, TFC of extruded oats decreased, and at a barrel temperature of $110^{\circ}C$, PD of extruded sorghum without $CO_2$ decreased. Some physical properties [expansion ratio (ER), specific length, piece density, color, and water absorption index] of the extrudates were significantly affected by the increase in barrel temperature. The $CO_2$ injection significantly affected some physical properties (ER, specific length, piece density, water solubility index, and water absorption index), TPC, DPPH, ${\beta}$-glucan, and PD. In conclusion, extruded barley and millet had higher potential for making value added cereal-based foods than the other cereals.

• 대한화학회지
• /
• 제33권1호
• /
• pp.11-17
• /
• 1989

피라지니움염인 피라지니움 크로로크로메이트와 디피라지니움 트리크로로메이트는 HCl용액과 $CH_2Cl_2$용액에 피라진을 각각 녹이고 거기에 CrO$_3$ 를 가하므로 얻었다. 이들 화합물은 모두 비흡수성이나 물에 잘 녹었다. 이들 화합물의 물리적 특성으로 용해도, pH, 전기전도도, 용융점 등을 측정하였다. 이들 화합물은 전기 전도도 측정으로 $C_4H_4N_2H^+$, $CrO_3Cl^-$, $Cr_3O^{2-}_{10}$ 이온 등으로 용액 내에 존재하는 것을 알 수 있었다. 또한 DTA에 의해 염의 첫번째 분해시에 CrO$_3$ 가 분리되고 두번째 분해시에는 $Cr_2O_3$로 변해지고 이때 무게가 감소됨을 알 수 있었다. 특히 동일한 조건하에서 디피라지니움 염은 피리딘으로부터 얻어진 $Cr_2O^{2-}_{7}$의 형태로 존재하리라 예측했던 것이 이소폴리의 형태로 존재함을 알 수 있었다.

• 상하수도학회지
• /
• 제35권6호
• /
• pp.425-436
• /
• 2021

In this study, chemically enhanced steam cleaning(CESC) was applied as a novel and efficient method for the control of organic and inorganic fouling in ceramic membrane filtration. The constant filtration regression model and the resistance in series model(RISM) were used to investigate the membrane fouling mechanisms. For total filtration, the coefficient of determination(R²) with an approximate value of 1 was obtained in the intermediate blocking model which is considered as the dominant contamination mechanism. In addition, most of the coefficient values showed similar values and this means that the complex fouling was formed during the filtration period. In the RISM, R _c/R _f increased about 4.37 times in chemically enhanced steam cleaning compared to physical backwashing, which implies that the internal fouling resistance was converted to cake layer resistance, so that the membrane fouling hardly to be removed by physical backwashing could be efficiently removed by chemically enhanced steam cleaning. The results of flux recovery rate showed that high-temperature steam may loosen the structure of the membrane cake layer due to the increase in diffusivity and solubility of chemicals and finally enhance the cleaning effect. As a consequence, it is expected that chemically enhanced steam cleaning can drastically improve the efficiency of membrane filtration process when the characteristics of the foulant are identified.

• 한국식품과학회지
• /
• 제30권2호
• /
• pp.372-378
• /
• 1998

Formaldehyde첨가 대두단백필름과 formaldehyde흡착 대두단백필름을 대조구용 대두단백필름과 함께 제조하여 각 필름의 색깔, 인장강도, 연신율, 투습도 및 수분용해도 등을 측정하여 제조방법에 따른 효과를 조사하였다. formaldehyde의 처리방법에 따라 필름의 특성은 크게 영향을 받았다. formaldehyde첨가 대두단백필름의 물리적 특성은 대조구인 대두단백필름에 비해 큰 차이가 없었으나 formaldehyde흡착 대두단백필름은 그 특성이 크게 변하였다. Formaldehyde흡착 필름은 가교결합이 형성되어 필름의 수분용해도가 26.1%에서 16.6%로 크게 감소하였으며, 인장강도는 2배가 증가한 반면 필름의 연신율은 2배로 감소하였다. 이는 formaldehyde와 반응하여 단백질 분자 사이에 가교결합이 형성되면서 단백질이 불용화 및 경화되었기 때문이다.

• Journal of Pharmaceutical Investigation
• /
• 제27권4호
• /
• pp.265-269
• /
• 1997

An inclusion complex of muscone with ${\beta}-cyclodextrin$ (CD), as a solid form of muscone, was prepared to increase the solubility of muscone. The molar ratio of muscone to ${\beta}-CD$ in complex was in the range of $1:1{\sim}1:5$ when prepared by freeze-drying method. The interaction of muscone with ${\beta}-CD$ in solid state was investigated by Infrared (IR) spectroscopy and differential scanning calorimetry (DSC). IR and DSC studies between $muscone-{\beta}-CD$ inclusion complex and physical mixture showed that $muscone-{\beta}-CD$ inclusion complex was prepared stably. From the amount of muscone incorporated in the inclusion complex, it was found that the molar ratio of muscone : ${\beta}-CD$ was 1:1. Relative spatial position of muscone and ${\beta}-CD$ was observed by Hyperchem molecular modelling program.

• Journal of Pharmaceutical Investigation
• /
• 제31권3호
• /
• pp.167-172
• /
• 2001

All-trans retinoic acid (ATRA), vitamin A acid, has been shown to exert anticancer activity in a number of types of cancers, particularly in acute promyelocytic leukaemia (APL). Due to its highly variable bioavailability and induction of its own metabolism after oral treatment, development of parenteral dosage forms are required. However, its poor aqueous solubility and chemical unstability give major drawbacks in parenteral administration. This study was undertaken to investigate a possibility to develop a parenteral formulation of ATRA by employing solid lipid nanoparticle (SLN) as a carrier. By optimizing the production parameters and the composition of SLNs, SLNs with desired mean particle size (<100 nm) as a parenteral dosage form could be produced from trimyristin (as solid lipid), Egg phosphatidylcholine and Tween 80 (as SLN stabilizer). The mean particle size of SLN formulation of ATRA was not changed during storage, suggesting its physical stability. Thermal analysis confirmed that the inner lipid core of SLNs exist at solid state. The mean particle size of ATRA-loaded SLNs was not significantly changed by the lyophilization process. ATRA could be efficiently loaded in SLNs, while maintaining its anticancer activity against HL-60, a well-known APL cell line. Furthermore, by lyophilization, ATRA loaded in SLN could be retained chemically stable during storage. Taken together, our present study demonstrates that physically and chemically stable ATRA formulation adequate for parenteral administration could be obtained by employing SLN technology.