Why Radio frequency heating is more effective to deactivate and release non-nutritive components from pulses

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Canadian pulse industries are growing fast and export sales of pulses increased rapidly over past years. Radio frequency heating is energy efficient and suitable for large-scale commercial applications, but has been implemented in limited areas. The goal of my research is to discover the mechanism of the microstructure changes that occur during pulse processing and their effect on product quality. The project requires three work packages. Work package 1: Synchrotron 3D X-ray imaging of pulses The 4th generation synchrotron on the U of S campus will be used to study 3D X-ray images of pore, water, protein, and starch distributions under controlled RF heating conditions. We will study enhancement of the contrast in X-ray imaging in-line phase-contrast tomography with coherent X-ray sources accessible via synchrotron radiation. Using Biomedical Imaging and Therapy Facility at Canadian Light Source, 3D images of microchannel development, changes in the density and distribution of pore, water, protein, and starch in the pulses will be studied in detail. We will also compare the 3D skeletonized pore spaces of pulses treated with conventional roasting and high-power RF heating. Work package 2: Vertical applicator design for optimized particle flow To use an RF heating system efficiently, it is critical to have a properly designed applicator in place. To ensure a continuous (no gaps) and uniform flow of particles into the space between the two electrodes, we will design and build vertical applicators. For particle flow, we will consider a free-falling type with an actuator at the exit and an auger type. We will test parallel and co-axial electrode configurations. Computer simulations based on the discrete element method will be conducted for both types using different parameters for design optimization. The optimized applicators will be fabricated, and tested for particle flow and temperature distribution during RF heating. Work package 3: Pulse quality comparison During RF heating with the selected applicators from Work package 2, we will observe how non-nutritive components are deactivated and released from the pulses under various operating conditions. Parallel tests will be performed to compare RF heating with conventional thermal gradient-driven roasting. After optimization of the process conditions, additional quality parameters (colour, texture, protein, and starch) will be compared for the two heating methods. The non-nutritive components removal will be quantitatively correlated with synchrotron X-ray images and temperature gradients inside the pulses for both RF heating and conventional roasting. It is clear that the results of these three areas of research will have a significant positive impact and will add value to a wide array of pulse products in Canada. The program will also provide quality training for HQPs through interdisciplinary research.