In this study an experimental infrared system was designed and built to investigate the deactivation behavior of peroxidase in eggplant. Deactivation of peroxidase (90% reduction in enzyme activity) in eggplant slices was investigated during infrared irradiation at powers of 150, 250 and 375 watts and thickness of 5 and 10 mm in the range of 0 to 600 seconds. During the process, changes in cold spot temperature, moisture and peroxidase activity in slices of eggplant were measured. The results showed that using 150 W lamp at a thickness of 5 and 10 mm in, peroxidase was not inactivated after 600 seconds. The peroxidase enzyme was inactivated by using lamps with powers of 250 and 375 at a thickness of 5 mm after 500 and 150 seconds, respectively in which was associated with reduction of 50.06% and 31.62% of the initial moisture content at cold spot temperature of 73.76 o.C and 44.72 o C , respectively, using lamps with powers of 250 and 375 at a thickness of 10 mm after 600 and 200 seconds was associated with a reduction of 50.26% and 33.04% of the initial moisture content at cold spot temperature of 72.27o C and 73.86 degrees o C, respectively, In conclusion, increase in power and decrease in thickness, increased inactivation rate of enzyme peroxidase furthermore, because of the shortening of the processing time when using lamps with larger power the less moisture is removed from the sample.

In this study, the combination of infrared - hot air dryer was used for drying of button mushroom. The effect of infrared lamp power (150, 250 and 375 W), hot air temperature (50, 60 and 70oC) and hot air rate (1, 2 and 3 m/s) on drying of button mushroom were investigated. The results of infrared-hot air drying of button mushrooms showed that by increasing of lamp power from 150 to 375, the drying rate increased. With the increase in hot air temperature from 50 to 70oC, and hot air rate from 1and 3 m/s, weight loss increased 10.3% and 13.9%, respectively. Also process modeling were done with the genetic algorithm–artificial neural network (GA-ANN) method with 4 inputs (lamp power, hot air temperature and rate, drying time) and 1 outputs for prediction of weight loss. Sensitivity analysis results by optimum GA-ANN showed the drying time of mushroom was the most sensitive factor for controlling of weight loss. The results of modeling by GA-ANN showed that a network with 7 neurons in the hidden layer with sigmoid activation function can predicted the weight loss (R=0.99) of button mushrooms dried by infrared system-hot air method.

Introduction: Modeling might be considered as a relationship between different variables during drying of food products and mass transfer kinetics and moisture diffusivity coefficients can be used as useful tools for the optimal control of the process conditions that improve the quality of the final dried product. Kiwi fruit has favorable taste and aroma and has a high nutritional value. The aim of this research work is to investigate the effect of radiation on the characterization of Kiwi fruit.Materials and Methods: In this study the effect of radiation lamp power at three levels of 200, 250 and 300 W, at 5, 10 and 15 cm distance from sample surface on mass transfer kinetics, moisture diffusion coefficients, density, color change, texture and rehydration of the Kiwi were investigated.Results: The results showed that the lamp power and the distance from the sample surface have significant effect on moisture loss kinetics and drying time. By increasing the infrared lamp power, the weight loss is increased (61.01%) and by increasing the infrared lamp power from 200 to 300 W, the effective diffusivity coefficient has been increased from 6.25×10-10 m2/s to 13.8×10-10 m2/s. The color of the samples were analyzed by image processing technique and the average color changes (DE) for 200, 250 and 300 W were 14.02, 19.09 and 21.66, respectively. The average density and rehydration for dried samples were 743 kg/m3 and 229.18 %, respectively.Conclusion: The effect of infrared power on effective diffusivity coefficient of Kiwi was investigated and found that the effective diffusivity coefficient is increased by increasing the source of heat. The hardness of dried kiwi slices through infrared dryer was in the range of 9.55-11.08 N. In the Kiwi drying process modeling as compared with other models, Page model had the best match with the experimental results.

Due to the damage that air can cause to the intestines and diaphragm, it is essential to prevent air from entering peritoneal dialysis fluid. Bubble detection systems and air infiltration control systems are mandatory components of peritoneal dialysis machines. An infrared sensor is one of the most efficient ways to detect bubbles in the catheter tube. As the dialysis fluid passes through the infrared sensors, an output of approximately 1200 millivolts is produced. The voltage produced by infrared sensors is independent of the device's speed. Approximately 1200 millivolts can be obtained when the motor of the dialysis machine operates at speeds of 50, 40, and 30 RPM. Continuous measurement of this voltage is performed, and the processor checks the correctness of bubble detection by limiting the threshold level of output voltage. This threshold control to detect bubbles in the dialysis machine tubes is 1000 millivolts. If the output voltage drops below this value, the operation of the dialysis machine is prevented to prevent possible injuries to the patient.

Background and objectives: Button mushroom (Agaricus bisporus) is a food with high nutritional value that is allocated about 40% of the mushroom market share and contains 32. 5 % protein, 1. 6 % fat, 9. 2 % fibre, 7. 5 % ash, 6. 8 % moisture, and 42. 4% carbohydrate on dry weight basis. Button mushroom is highly perishable product with a maximum shelf-life of eight days at 4° C. Thus, in order to increase the shelf life of button mushroom and produce high quality product, infrared (IR) dryer was used in this study and mass transfer kinetics of the samples were measured. Materials and methods: In this study, drying of button mushroom in an infrared dryer at irradiation power of 150, 250 and 375 W and distances of 5, 10, 15 and 20 cm were investigated. The effect of lamp power and sample distance from radiation source (IR lamp) on drying time and rate, and moisture diffusion coefficients was investigated in a factorial experiment by completely randomized design. For drying kinetics modeling, nine mathematical models containing Fick's Diffusion, Approximation of diffusion, Page, Modified Page – II, Newton, Midilli, Logarithmic, Verma and two term were evaluated and the best model with the highest correlation coefficient and the lowest standard error was selected. Results: The results showed that the effect of IR lamp power and distance is significant on the drying process of button mushroom. Increase in IR lamp power from 150 to 375 W, and the reduction of distance from 20 to 5 cm decreased the drying time of button mushrooms 56. 6 and 55. 3 %, respectively. The maximum drying time was related to the power of 150 W and 20 cm IR lamp distance, which took 190 minutes to complete the process. Furthermore, the lowest drying time is related to 375 W power and 5 cm lamp distance with a record period of 30 min. Due to increasing the lamp power and reducing IR lamp distance in the drying process of button mushroom, the effective moisture diffusivity coefficient was an increasing trend. By increasing the lamp power from 150 to 375 W, the effective moisture diffusivity coefficient (at a distance of 5 cm from the lamp) is increased from 3. 8×10-9 m2s-1 to 11. 0×10-9 m2s-1. By increasing the sample distance from 250 W lamp, from 5 to 20 cm, the effective moisture diffusivity coefficient for a button mushroom decreased from 7. 0×10-9 m2s-1 to 2. 2×10-9 m2s-1. Conclusion: Effective diffusivity coefficient of button mushroom moisture was obtained between 1. 2×10-9 to 11. 0×10-9 m2/s. In modeling of mushroom drying process, Page model was better fit with the experimental results compared to other models.