In this study, the effect of ohmic heating technique on electrical conductivity, water evaporation rate, heating rate, colour parameters, pH and energy consumption of tomato samples was investigated. Ohmic heating was accomplished till the moisture content of the tomato samples reduced from initial moisture content of as 9.33 (dry basis) to a safer level of 2.2. The results of the nonlinear mathematical model including the effects of voltage gradient level and the temperature on the electrical conductivity changes had good agreement (R≥ 0.955) with the experimental data. Also, it was observed that the electrical conductivity increased along with concentration of tomato samples. The range of electrical conductivity during ohmic heating was 3.19-8.95 (S/m). It was found that processing time decreased from 28.32 to 4.3 min over the voltage gradient range studied (6 to 14 V/cm), which resulted in decreased specific energy consumption from 4.63 to 3.05 (MJ/kg water). Due to increasing of heating rate and water evaporation rate at high voltage gradient, the change of the pH was limited. Samples processed in high voltage gradient had higher L*, b* and hue angle (h), lower a* and Chroma (C) values as compared to low voltage gradient. The optimum value of processing time, pH, colour, specific energy consumption was obtained at 14 V/cm voltage gradient level.

No abstract

No abstract

Because of high porosity and stickiness of mint leaves, they could not be fluidized well during fluidization. In this study, a vibro-fluidized bed dryer assisted heat pump system was designed and fabricated to overcome this problem. The drying experiments were carried out at temperatures of 40, 50 and 60 ?C. The quality of the dehydrated samples was assessed based on color indices, antioxidant activity, and total phenolic content. Drying process primarily occurred in falling rate period. The effective coefficient of moisture transfer of the samples was increased with air temperature and varied from 4.26656?10-11 to 2.95872?10-10 m2 s-1 for heat pump drying (HPD) method, and 3.71918?10-11 to 1.29196?10-10 m2 s-1 for none-heat pump drying (NHPD) method. The color indices for temperatures of 40 and 50 ?C were very close to each other, whereas by increasing temperature to 60 ?C, a remarkable loss of green color was observed. The highest phenolic content was found in methanolic extract for HPD at 60 ?C, and NHPD at 50 ?C contained the lowest amount of phenolic compounds. NHPD treatments showed lower antioxidant activity compared to HPD treatments at the same temperature due to the longer drying times.

No abstract

This study numerically modeled the flow of a fluid (air) and solid particles (saffron flower) inside a cyclone using the finite volume method (FVM) in ANSYS Fluent. The continuous phase was simulated under steady state conditions, as the initial condition, using the Reynolds Stress Model (RSM) for turbulence at three constant inlet air velocities of 1.5 m/s, 2.5 m/s, and 3.5 m/s over the inlet section. One-way coupling was assumed to govern all numerical analyses. The fluid phase and particles were treated as the continuous medium (within a Eulerian framework) and discrete phase (within a Lagrangian framework), respectively. The equations governing the gas phase included the compressible Navier–Stokes and the conservation of mass. The discrete phase equations included the equations of motion for three different particles including petals, stigmas, and anthers. According to the numerical results, the cyclone separation efficiency was calculated, and the static pressure and velocity contours were plotted. The results showed the capability of the CFD-based simulation for an accurate demonstration of the behavior of the fluid–solid phase. Accordingly, it can be used to predict the efficiency of stigma separation from petals of saffron using airflow in the cyclone. According to the results, the highest cyclonic separation efficiency of 89% was achieved at an inlet air velocity of 3.5 m/s, which was very close to the experimental data.

No abstract

Electronic simulation of the five senses has received attention for many years. Additionally, electronic tongue (e-tongue) is a concept created for the electronic detection of tastes. Today, this concept is used more generally and means the identification and detection in the presence of liquid (Kaushal & Mudhalwadkar, 2020). In e-tongue, an array of sensors converts the chemical compounds of an unknown solution into an electrical signal. The responses are transferred to the processing unit. In the processing unit, the information hidden in the responses is drawn out using pattern recognition methods and used to analyze the analyte. The array responses consisting of