Preliminary Study of Heat Distribution in Sweet Potatoes Heated by Microwave

Abstract

Electromagnetic wave can directly affect temperature generation and distribution in foodstuff heated by microwave oven. The heat distribution of sweet potatoes temporally takes many forms using the domestic microwave oven with a single source of micro wave 2.45 GHz. The treatment of food using microwave oven is largely consentrated on the dielectric properties of foodstuff. This study aims to simulate the distribution of heat in sweet potatoes in a microwave oven with various geometric shapes and sizes. The shape of the sample used in this research is sphere and cylindrical. Heat distribution modeling on a microwave oven uses finite element method as a support for the study. The effects of the shape and size of the sweet potato is very influential on the heat distribution that occurs in the sweet potato sample. The influence of the shape and size of the sweet potato is due to the large penetration depth of the sweet potato so the microwaves absorbed by the sweet potato depend on the thickness and shape of the sweet potato. The conduct simulation was showing the heating process using the microwave did not spread from the sample surface to inside the sample yet from the midpoint caused by the microwave conversion to the heat. Afterward, it spreads to the surface subsequently after the microwave has passed the depth of penetration of the sample. The spherical shape has a very fast temperature rise compared to the cylindrical shape. The sphere with a radius of 42 mm took time 60 seconds for the heat in the sample to reach 100⁰ C with almost equal heat distribution.