Novel processing methods for enhancing nutritional quality and functionality of foods

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In my research program on post-harvest technologies, we have worked on novel, effective, and energy efficient methods to dry and thermally treat foods to better retain its nutritious and health beneficial contents, extend its shelf life, and ensure food safety. The activities in this proposal build upon this. We propose to develop an intelligent real-time control system for microwave fluidized bed drying system (MWFBD) and to study the use of non-thermal methods (ex. electrohydrodynamic drying (EHD), ultrasound, non-thermal plasma (NTP)) for processing foods without degrading heat-sensitive health-beneficial components (ex. vitamins). To develop a real-time system to control drying of peas and sliced vegetables in a MWFBD, we have assembled an on-line monitoring system that uses computer vision. We are developing algorithms to analyze images for changes in size and colour of the food material as it undergoes drying. The main challenge is that the food particles are constantly moving. The data generated by this system will be used in conjunction with information on compositional and qualitative changes in the food as it dries to train artificial neural networks to use this data to provide intelligent control of the dryer to result in nutritious and desirable products. In our work on non-thermal drying, we noted that using high voltage fields such as in EHD had an effect on protein structures, which could affect protein functions such as digestibility and allergenicity. The implications are of great interest since these are major concerns of society. We studied the effects of non-thermal processes on protein structures in soybeans, kiwifruits, shrimps, etc., using tools such as circular dichroism and molecular dynamic simulations to determine and to visualize changes in protein conformation. We will continue these studies using more advanced tools such as laser imaging mass spectrometry. We have discussed with a medical group working on allergies to do clinical trials on the allergenicity of processed kiwifruit proteins. We are working on a non-thermal method to decontaminate fresh produce, especially leafy vegetables that are difficult to sterilize without affecting the food. Water treated with NTP results in the formation of components that have antimicrobial property (ex. hydrogen peroxide, ozone, nitrites, nitrates). The plasma activated water (PAW) can thus be used as a wash to decrease bacterial load on the produce. The active components readily degrade and thus have little environmental impact. We will study the effects of PAW on the nutritional and physical properties of the food. This work will develop control systems and techniques that will be of use to researchers and industry in the food processing sector to enhance the quality of food products. This program will train personnel and provide excellent career options as evidenced by the success of recent graduates in finding positions in Canadian food companies and institutes.