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In this study, coupled mechanical-biospeckle imaging method was performed on potato tubers subjected to creep and uniaxial compression tests. Using this method, we analyzed the characteristics of biospeckle images in relation to the structural changes of potato tissue on loading. During mechanical tests, the speckle pattern images were recorded. The biospeckle activity indices including entropy of the wavelet transform, contrast of successive correlations (CSC), inertia moment, and absolute value of differences were calculated to extract features from the captured videos. The results revealed that the entropy could be an acceptable parameter to assess structural changes and locate rupture point of tuber in the compression test. Analysis of the biospeckle images also showed that the CSC has a decreasing trend during the creep test. Prediction models of mechanical properties were developed by fuzzy c-means clustering algorithm and were optimized using the ANFIS and genetic algorithm. The results can provide the confidence to use this method in drying, frying, and all processes that cannot be taken out samples of it. [ABSTRACT FROM AUTHOR]

The aim of the present work was to assess the influence of high-intensity airborne ultrasound application on duration and energetic performance of hot air drying of peppermint leaves. To this end, drying experiments were conducted at constant air flow rate of 1 m s−1 and different temperatures (40, 50, 60 and 70 °C) without and with application of ultrasound power (90, 180, 270 and 360 W). The results showed that the maximum (170.84 MJ kg−1) and the minimum (63.36 MJ kg−1) specific energy consumptions belonged to convective drying at temperature of 40 °C and ultrasonic-assisted drying at 60 °C and 270 W, respectively. Energy efficiency varied from 1.41 to 3.69%. Depending on the power level, application of the ultrasound power at the air temperatures less than 70 °C reduced drying time and improved energetic performance of the process. The obtained findings in this research declare that acoustic power could be effectively used in combination with convective dryers to reduce duration and energy required for drying of heat-sensitive products. • Ultrasound power ability to improve energy efficiency of drying process was studied. • Application of the power reduced the process duration of up to 41%. • At temperatures less than 70 °C, ultrasound power increased the energy efficiency. • The values of energy efficiency ranged from 1.41 to 3.69%. • The power has good ability to reduce the process duration and energy consumption. [ABSTRACT FROM AUTHOR]

An accurate understanding of moisture transfer parameters, including moisture diffusivity and moisture transfer coefficient, is essential for efficient mass transfer analysis and to design new dryers or improve existing drying equipments. The main objective of the present study was to carry out an experimental and theoretical investigation of mushroom slices drying and determine the mass transfer characteristics of the samples dried under different conditions. The mushroom slices with two thicknesses of 3 and 5 mm were dried at air temperatures of 40, 50 and 60 °C and air flow rates of 1 and 1.5 m s. The Dincer and Dost model was used to determine the moisture transfer parameters and predict the drying curves. It was observed that the entire drying process took place in the falling drying rate period. The obtained lag factor and Biot number indicated that the moisture transfer in the samples was controlled by both internal and external resistance. The effective moisture diffusivity and the moisture transfer coefficient increased with increasing air temperature, air flow rate and samples thickness and varied in the ranges of 6.5175 × 10 to 1.6726 × 10 m s and 2.7715 × 10 to 3.5512 × 10 m s, respectively. The validation of the Dincer and Dost model indicated a good capability of the model to describe the drying curves of the mushroom slices. [ABSTRACT FROM AUTHOR]