Electrohydrodynamic drying of agricultural products
Authors: Singh, A, V Orsat, Gsv Raghavan
Description: Drying is one of the most important unit operation applied for preservation of agricultural products. It reduces the water activity of the product making it less susceptible to microbial growth. Conventional drying techniques such as hot-air drying, fluidized bed drying etc. are highly energy-intensive and affect an array of physical and chemical characteristics of the product. Application of high drying temperature during conventional drying negatively impacts the nutritional and organoleptic properties of the products making it unsuitable for heat sensitive materials. Recent change in consumer demand for high quality products and increasing environmental concerns have led to application of novel techniques such as freeze drying, microwave, and radio-frequency either alone or in combination with conventional techniques to improve the efficiency and quality of the drying process. Electrohydrodynamic drying (EHD) is a method of inducing electric wind that is generated by gaseous ions under the influence of a high-voltage electric field. Impingement of the electric wind on the biological matrix disrupts the saturated air layer and promotes diffusion of water from within on to the surface of the matrix, leading to evaporation enhancement. Interaction of the ionic wind with the biochemical components such as protein, phenolic antioxidants and starch of the biological products and the quality parameters such as colour, texture and firmness is not well understood. The present paper relates the operational parameters of the EHD process with these organoleptic and nutritional properties of the product.
Keywords: electrohydrodynamic drying, ionic wind, electric field
Technical field: technical_fields_app4
Session name: Food and bioprocess engineering