Physicochemical properties and storage stability of plant-based alternative meat prepared with low-fat soybean powder (LPAM) treated by supercritical-CO2 and those of full-fat soybean powder (FPAM) were compared. Ash and crude protein contents were higher in LPAM than in FRAM. Water absorption capacity and oil absorption capacity were significantly higher in LPAM than in FPAM. Water binding capacity was higher in LPAM than in FPAM during a 20 days storage period at 5℃ and pH was significantly lower in LPAM than in FPAM after a 5~10 days storage period. Hardness, gumminess and chewiness significantly increased with the increase in the storage period, and the three were significantly higher in LPAM than in FPAM after 10 days and 20 days of storage. The acid value showed no remarkable difference according to the storage period in LPAM; however, it was significantly higher in FPAM than in LPAM after 20 days of storage. The peroxide value and TBA value were significantly increased according to the storage period, and were significantly lower iin LPAM than in FPAM during all the storage periods. Therefore, the use of low-fat soybean powder may be effective in improving oxidative stability during storage in the production of plant-based alternative meat.

Radioactive contamination of soil on the site of a nuclear facility has a characteristic that radioactive nuclides are adsorbed into the pores between soil particles, making it quite difficult to decontaminate. For this reason, research on the development of various decontamination processes is being actively conducted. In this study, among various decontamination studies, a soil decontamination process using supercritical carbon dioxide was presented. The decontamination process uses supercritical carbon dioxide as the main solvent, which has a higher penetration power than other materials. Therefore, the process consists of the process of desorbing and extracting the target radionuclides between particles of soil. However, since nuclides exist as ions in the soil, polar chelating ligand material was introduced as an additive to nonpolar supercritical carbon dioxide for smooth chemical reactions in the soil. Thereafter, from the viewpoint of improving process continuity and efficiency, an alcohol material was introduced as an auxiliary solvent for liquefaction of chelating ligand in a solid state. Through prior research on the selection of a solvent for liquefaction of chelating ligand, ethanol and 2-propanol were finally selected based on whether the chelating ligand was dissolved. However, if the auxiliary solvent in which the chelating ligand is dissolved is to be combined with radionuclides in the soil, it must first be well dissolved in supercritical carbon dioxide, the main solvent. Therefore, in this study, the solubility of ethanol and 2-propanol in supercritical carbon dioxide was measured and the suitability was evaluated. The temperature conditions were carried out at 40°C, the same as the previously designed decontamination process, and the measurement was conducted by adjusting the pressure and volume through a syringe pump and a variable volume device. In addition, solubility was measured based on the observation of the ‘cloud point’ in which the image becomes cloudy and then bright. As a result of the experiment, several solubility points were measured at a pressure of 150 bar or less. If the flow rate ratio of supercritical carbon dioxide and auxiliary solvent derived from the results is applied to the soil decontamination process, it is expected that the process efficiency will increase in the future.

This study was carried out to investigate the effects of supercritical carbon dioxide (SC-CO2) extracts from sweet potatoes (SP) and watermelon (WM) on the oxidative stability of perilla seed oils (POs) over the existing ones. A comparison was done between the oxidative stability of perilla oil (PO) after the addition of 0.1% of SP, and WM extracts and PO without extract. The oxidative stability was measured based on the viscosity, acid value (AV), peroxide value (POV), antioxidant (DPPH) activity, p-anisidine value (p-AV), and fatty acid composition. The viscosities ranges were: PO without extract, from 53.99±0.99 to 74.38±1.61 cps, PO with SP extract, from 53.99±0.10 to 58.73±0.8 cps, and PO with WM extract, from 53.98±0.10 to 56.00±0.70 cps. While the PO containing the SC-CO2 extracts had significantly lower AV, POV, and p-AV, their antioxidant activity was approximately 10 times higher than that of the PO without extract. There were no significant differences in fatty acid composition between SC-CO2 extracts added groups and PO without extract (p<0.05). The findings of this study confirmed that the SC-CO2 extracts from sweet potatoes and watermelon enhanced the oxidative stability of perilla seed oils, and are potential natural antioxidants for use in the food industry.

Micro-electromechanical systems (MEMS) 구조물용 고 종횡비의 외팔보 제작을 목적으로 초임계 이산화탄 소를 사용한 건식 식각 실험을 진행하였다. 건식 식각 실험은 초임계 이산화탄소에 50% 불산 (HF) 원액과 공용매 (물, 메탄올, 에탄올, 이소프로필 알콜)를 사용하여 진행되었다. 희생 실리카 층을 식각하여 드러난 MEMS 외팔보 빔 은 주사전자현미경을 이용하여 관찰하였다. HF원액을 사용한 건식 식각 실험은 종횡비 1 : 150의 외팔보 빔까지 기 판과 접착없이 단독으로 서 있는 형태로 제작되었다. 공용매로 메탄올과 에탄올을 사용한 건식 식각의 결과에서는 종 횡비 1 : 75 까지 접착없이 제작할 수 있었고, 이소프로필 알콜을 공용매로 첨가한 실험 결과에서는 종횡비 1 : 37.5 까지 접착없이 제작할 수 있었다. 본 연구의 결과 건식 식각과정에서 알콜계 공용매의 첨가는 대체로 식각 성능을 저 하시킴을 알 수 있었다.

Curcumin, the major yellow-colored pigment in turmeric(Curcuma longa L.), was extracted by using supercritical carbon dioxide. Optimum extraction conditions were determined. Overall experiments were planned by central composite design and results were analyzed by response surface methodology to find effects of three independent variables, temperature(X1), co-solvent flow rate(X2) and pressure(X3) on the yield of curcumin extract(Y). Regression model optimized by response surface analysis was as follows Y = -8.581270 + 0.220770X1 + 1.176731X2 + 0.036873X3 + -0.0026816X12 - 0.013010X2X1 - 0.103353X22 + 0.000198X3X1 - 0.0000825X3X2 - 0.000096554X32. Optimum temperature, pressure and co-solvent flow rate for extracting curcumin from turmeric were 40.31oC, 3.07 ml/min and 231.59bar, respectively, and statistical maximum yield of curcumin was 1.922%.

Hydrolysis of triacylglycerol(TAG) from fats and oils to glycerol and free fatty acid (FFA), also referred to as fat splitting, is an important reaction for the olechemical industry. Typically, hydrolysis is carried out at 100-260℃ and 100-7000 kPa using 0.4-0.15(w/w) initial water to oil ratio with or without catalysts. It is an endothermic reaction occurs in a stepwise manner where TAG is initially hydrolyzed to diacyglycerol (DAG) then to monoacylglycerol(MAG) and finally to glycerol. Water, in its subcritical state, can be used as both a solvent and reactant for the hydrolysis of triglycerides. subcritical water (150℃<T<370℃,0.4<p<22Mpa) can act as an acid or base catalyst. To investigate milder reaction conditions, in this study, waste cooking oil and fresh soybean oils will be hydrolyzed to free fatty acids with deionized water under SC CO2 medium in a batch reactor. Effects of the reaction temperature, time and solvent to feed ratio on FFA in the hydroysis at equilibrium will also observed for optimum conversion of oil. The reaction products will be analyzed by acid-base titration, GC FID and HPLC.

Deacidification of waste cooking oil such as, palm oil or soybean oil, using supercritical carbon dioxide (scCO2) extraction has been widely investigated for reusing waste cooking oil. The deacidification process using scCO2 has been carried out under various experimental conditions temperature range between 40 and 100oC, pressure range between 20 and 35 MPa, CO2 flow rate range between 10 and 40 g/min, and extraction time range from 1 to 7 hours. The purified waste oils were characterized by their acid value and peroxide value measured. The optimized conditions were deduced in this paper at the temperature of 80oC, pressure of 20 MPa, and CO2 flow rate of 40 g/min. At the optimized operating condition the peroxide value was existed between 40 and 100. Also 80% of the purified oil was recovered. The properties of the purified oil were shown as similar to those of the pure oil.