Microwave puffing: Determination of optimal conditions using a coupled multiphase porous media – Large deformation model

Increased interest in microwave puffing is due to its ability to obtain low-fat and ready-to-eat healthy products. Determination of optimal conditions for this complex process has been difficult and although several patents exist on the concept, we are yet to see any large scale commercial use. A fundamental physics based modeling approach integrated with relevant experimentation, developed in this work, is an ideal framework to understand and optimize microwave puffing. The results showed that puffing may not be successful unless carried out using an intensive heating source such as microwaves. Addition of infrared and hot air leads to better quality product whereas using forced air convection is not desirable. There is an optimum initial moisture content depending on the puffing conditions. The study provides critical guidelines to food product/process developers for successful development, control and automation of microwave puffing, thereby leading to value-added nutritious products.

► We develop a fundamentals based computational model for microwave puffing.
► Very high temperatures are required to generate pressures needed for puffing.
► Infrared addition to microwave puffing leads to a better quality product.
► Forced air convection in addition to microwave heating is not desirable.
► Relative humidity has no effect on the puffing characteristics.