Steam tables including superheated, saturated and compressed region were simultaneously modeled using the neural networks. Pressure and temperature were used as two inputs for superheated and compressed region. On the other hand Pressure and dryness fraction were two inputs for saturated region. The outputs were specific volume, specific enthalpy and specific entropy. The neural network model were compared with the linear interpolation model in terms of the percentage relative errors. The criterion of judgement was selected with the percentage relative error of 1%. In conclusion the neural networks showed better results than the interpolation method for all data of superheated and compressed region and specific volume of saturated region, but similar for specific enthalpy and entropy of saturated region.

The state variables of saturated and superheated region in the steam table were simultaneously modeled using the neural networks. And the results were compared with quadratic spline interpolation and Lagrange interpolation. Two input data without distinguishing parameter were used in the neural networks. For comparison, quadratic spline interpolation method for superheated region and Lagrange interpolation method for saturated region were applied. The overall results revealed that the neural networks were greatly superior to quadratic interpolation method or Lagrange interpolation method.

The purpose of this study is to investigate the effect of superheated steam (SHS) treatment on the inactivation of an enzyme involved in the racidity of brown rice as well as the degree of rancidity during storage of brown. Brown rice was treated with SHS at temperatures of 160oC, 200oC, and 240oC, and the result showed that the degree of starch damage was higher in the brown rice treated with SHS at higher temperature. Lipoxygenase was inactivated by treating with SHS for 20 s at 160oC, 15 s at 200oC, or 5 s at 240oC. The acidity and sensory evaluation of the brown rice treated with SHS showed that the acidity was decreased as the SHS treatment increased and SHS temperature became higher. The result of the sensory evaluation showed a similar tendency. These results show that the SHS treatment has potential as a method for improving the brown rice storage quality.

Physicochemical properties of potato chip treated with superheated steam (SHS) at various temperatures (120, 150, 180, and 220oC) and durations (2, 5, 8, and 10 min) were measured to assess the potential application of SHS in the production of unfried chips. A faster drying rate was obtained at a higher SHS temperature due to a lower degree of water condensation on the surface of the potato chip. A higher temperature of SHS resulted in higher volume shrinkage, indicating the dependency of shrinkage on the volume of water loss. SHS treatment did not cause any significant defects in the appearance of potato chips although pillowing and burnt spots were observed on the surface of the sample processed at 220oC for 10 min. Damaged starch content and Rapid Visco Analyzer profiles showed that partial gelatinization occurred during SHS treatment. Potato chips treated with SHS showed the shrinkage of parenchyma cells, resulting to compressed cell layers at the surface and inside. As treatment proceeded, air cells were formed internally. These results suggested that SHS combined with post drying process would be appropriate in the production of unfried potato chips by reducing drying time without causing any deterioration in quality.

The processing properties of spent hen and broiler chicken were investigated before and after treatment to improve texture characteristics. Each treatment consisted steaming (S) with 85℃ for 20 min, Pulsed Electric Field (PEF) with 1.5 KV/cm for 4 sec, and Super Heated Steam (SH) with an oven temp. of 300℃, a steam temp. of 350℃ for 8 min. The yield of spent hen and broiler were 66.85% and 63.80% respectively in the control, but decreased in every treatment was lowest at 61.05% in the PEF treatment (p<0.05). In the color test, L value decreased, but the a and b values increased regardless of the species of spent hen or broiler. In the test of heating loss, the S treatment of spent hen had the highest result of 45.25% but lowest of 30.66% in the SH treatment of the broiler. When it was compared with various treatments, SH after PEF treatment showed the better result in terms of heating loss than the PEF or SH treatment respectively. In the test of texture, the broiler showed the lowest hardness of 5.57 kg in the SH (p<0.05). Otherwise, the spent hen resulted in 14.08 kg of hardness in steaming after PEF, but it improved significantly to 10.73 kg in SH after PEF. In the test of 9 scored sensory evaluation of overall palatability, 7.8 point was the best score with SH treatment in the broiler. The best score in spent hen was 6.3 point which was SH after PEF treatment. With this experiment, SH after PEF was the condition in the treatments to have the better texture of spent hen.

The optimization of brown rice replacement ratio and superheated steam (SHS) treatment conditions in production of extruded rice snack for infants were conducted using a response surface methodology. Experiments were designed using a Box-Behnken design with three independent variables (brown rice replacement ratio, SHS temperature, and SHS time) and two response variables (hardness and water uptake). The second order polynomial model showed a satisfactory description of the experimental results. Optimal conditions for extruded snack with the lowest predicted hardness (2.84 kg/cm2) were 15.81% of brown rice replacement with SHS treatment at 279.59oC for 197.40 sec. Meanwhile, optimal conditions for extruded snack with the highest predicted water uptake (384.79%) were 17.18% of brown rice replacement ratio with SHS treatment at 274.52oC for 196.22 sec.

과열증기처리한 백미로 제조한 압출스낵의 물리화학적 특성과 미세구조를 조사하여 과열증기처리 및 과열증기온도(200, 250, 350oC)가 압출스낵의 품질특성에 미치는 영향을 검토하였다. 압출스낵의 이화학적 특성 측정결과, 팽화도는 과열증기처리에 따라 증가하였으나 과열증기온도의 영향은 미미하였다. 압출스낵의 경도는 과열증기처리에 따라, 과열증기온도가 높을수록 감소하였다. 손상전분함량은 과열증기처리에 따라 78.1%에서 80-81%로 다소 증가하였으나 과열증기온도에 따른 손상전분함량의 유의 차는 없었으며, 이로써 과열증기처리가 전분호화에 미치는 영향은 크지 않은 것을 확인하였다. 과열증기처리에 따라 수분흡수지수(WAI)는 유사한 측정치를 나타낸 반면 수분용해지수(WSI)는 비교적 크게 증가하여 과열증기처리가 압출공정에서 전분분자의 저분자화를 증가시키는 것으로 판단되었다. 압출스낵의 수분흡수율은 과열증기처리에 따라 증가하였으며 과열증기온도가 높을수록 수분흡수율은 증가하였다. 압출스낵의 미세구조 관측결과, 압출스낵 내부의 기공 크기와 기공 막 두께는 과열증기처리에 따라 감소하며, 이와 같은 내부구조 변화로 인하여 과열증기처리 압출스낵의 팽화도, 경도 및 수분흡수율 측정결과는 대조구와 상이하였다. 한편 과열증기처리에 따른 압출스낵의 미세구조 변화는 과열증기처리가 쌀의 배유조직 내에 미세한 균열(stress crack)을 발생하고, 미세 균열 내의 공기가 압출과정에 유입되어 보다 많은 핵심이 생성되며, 이로 인하여 다공성이 높아지는 것으로 추정된다.

The steam table in saturated and superheated region was modeled simultaneously using the neural networks. A variable was introduced to distinguish between the saturation and the superheat. The relative errors were compared with the quadratic spline interpolation method. The relative errors by the neural networks were superior to those by the quadratic spline interpolation method over almost all ranges of temperatures and properties. The overall errors in the saturated region were better than those in the superheated region. From the analysis, it was confirmed that the neural networks could be a very powerful tool for simultaneous modeling of superheated and saturated steam table

The thermodynamic state variables in superheated region of steam table are not wholy obtained by measurements. This means that steam table contains a little error. In this study small error was artificially added to superheated variables and modeled using neural networks. The results were compared with the analysis using quadratic spline interpolation method. By and large the relative errors of variables by neural networks were sufficiently small and similar to or less than those by quadratic spline interpolation method. It was concluded that neural networks could be one good way of modeling for superheated steam table.

This study was conducted to develop radish as a food product for home meal replacement using superheated steam (SHS). Also, the change of quality characteristics was studied during their storage. The radish cuts were treated with SHS for 0, 3, 5, and 7 min, respectively, followed by complete drying at 80℃ for 6 hours. The results showed that radishes restored with mixed solution (drinking water:sugar:vinegar:salt=2:1:0.8:0.1) were harder than those restored with drinking water. All radishes were stored at 5, 10 and 15℃ for 56 days to investigate the changes of quality characteristics during the storage. Radishes in the control group, restored with drinking water and stored at 15℃, were spoiled after 7 days of storage. The radish in the experimental group did not show any change in the water content; except an increase on the first day of storage. The hardness of radish decreased with an increase in the storage period. It was found that microbial growth was inhibited due to low pH of the mixed solution, in which radishes of the experimental group were immerse.

The purpose of this study was to evaluate the effect of superheated steam drying on physicochemical and microbial characteristics of Korean traditional actinidia (Actinidia arguta) leaves. Actinidia leaves were dried at steam temperature of 350℃ and oven temperature of 150℃ for 40-200 sec. Moisture content and water activity decreased with increasing the drying time, while color values including L, a, and b values and total color difference (ΔE) increased as drying time increased. The relationship between moisture content and water activity showed an exponential fit with high correlation vlaue (R2=0.9909). Total phenolics and flavonoids content and antioxidant activity such as DPPH radical scavenging activity, ABTS radical scavenging activity, and FRAP assay of dried actinidia leaves increased with increasing the drying time up to 160 sec, but dramatically decreased at drying of 200 sec. The numbers of total areobic bacteria of leaves was not detected at drying time over 120 sec and coliform of all the samples was not detected. As a results, the superheated steam was an very effective drying method of increase to the nutritional and sanitary quality of dried Korean traditional actinidia leaves.

본 연구는 과열증기처리 기술을 양파에 적용하여 불쾌취 를 저감화하고, 이를 통해 고품질 양파 가공품 개발 및 소재 화에 활용하기 위한 기초 자료를 확보하고자 과열증기처리 에 따른 양파의 휘발성 물질, 불쾌취 유발 물질과 항산화활 성, 조직감, 관능적 특성 등 품질특성을 분석하였다. 과열증 기처리에 의해 휘발성 향기성분 및 불쾌취와 매운맛의 지표 물질이 저감화됨을 확인하였다. 항산화활성 및 총 페놀성 화합물 함량은 다소 증가하는 경향을 보였으며, hardness, chewiness 등은 확연하게 감소하는 것으로 나타났다. 양파 추출액의 총 가용성 고형분 함량은 처리에 의해 전체적으로 증가하였으며 처리에 따라 기호도 점수가 높아지는것을 확인하였다. 결과적으로 과열증기 처리가 양파의 불쾌취 저감화에 효과적임을 확인할 수 있었다. 본 연구결과는 과 열증기 기술을 적용한 양파의 불쾌취 저감화 및 이를 통한 다양한 고품질 가공품 개발 및 소재화를 위한 중요한 기초 자료로 활용될 수 있으리라 판단되며, 과열증기오븐 처리 를 통해 불쾌취를 조절함과 동시에 생리활성능을 지니는 향기 성분 및 유용성분의 감소는 최소화하는 추가적인 연구 가 필요할 것으로 사료된다.

This study focused on enhancing the mechanical properties and thermal stability of bio-composites with natural agricultural residues and improving the interfacial adhesion between polymer and biodegradable agricultural residual waste fibers. To achieve this purpose, we proposed superheated steam (SHS) treatment method as a novel pre-treatment of fiber for improved of compatibility in polymer matrix. The use of SHS-treatment was investigated as a method for improving interfacial adhesion between agricultural residual waste fibers and polymer and with the goal of enhancing mechanical properties. We selected wheat straw fibers for agricultural waste fibers to improve the surface modification. Wheat Straw Fibers (WSF) was treated with SHS in order to modify its characteristics for bio-composite applications. Treatment was conducted at temperatures 200oC and 230oC for each 1 h. SHS-treated WSF was evaluated for its chemical composition, thermal stability, morphology and crystallinity. Thermal stability of the fibers was investigated using thermogravimetric analysis and found that the degradation temperature of the fibers is increased after of the SHS treatment. In addition, SHS treatment contained in the WSF reduce the rate of hemicellulose components. The WSF is polar nature of lignocellulose due to the presence of hydroxyl and carboxyl groups in cellulose and hemicellulose causes it to be incompatible with non-polar thermoplastics. SHS-treatment was found to be able to remove hemicellulose, which is the most hydrophilic and most thermally unstable component in WSF, since it has the lowest thermal resistance. Removal of hemicellulose makes the fiber less hydrophilic and this will potentially increase the compatibility of treated WSF and polymers and improves the mechanical properties and water resistance of composites.