Microwave vs conventional popping system: A comparative evaluation for maize popping

Abstract

Microwave popping has vast and substitute technology in the field of food popping process over the conventional popping process for food grains such as maize, rice, sorghum etc. Basically, microwave processing is being performed by electromagnetic radiations with a microwave frequency of approximately 2,450 megahertz (MHz) and the main principle behind the food heating is dielectric heating which is absorbed by food material which have moisture content as a one component. This is the only one food processing operation which transfers the energy from inside to outside of the food items due to its volumetric heating rather than conventional heating source which transfers heat from outside to inside with temperature gradient and heat loss (based on conduction principle). In this article, studies on comparative analysis of popping characteristics were extensively done for poppable variety of maize grains using microwave radiation as heat source and existing conduction principle. Popping is a simultaneous starch gelatinization and HTST expansion process. This study aimed at providing brief knowledge on popping characteristics of maize grains such as popping yield and volume expansion ratio for obtaining high popping characteristics in best suitable method. It was found that popping characteristics (such as popping yield-85.62% to 90% mean of 87.81% and Volume Expansion Ratio - 6 to 8 folds) of American maize as compare to batch type of popping machine with popping yield-62% to 75% mean of 68.50 % and Volume Expansion (Ratio – 5 to 6 folds). These results were highest in microwave popping with less input of electric energy.