MICROWAVE BUMPING - QUANTIFYING EXPLOSIONS IN FOODS DURING MICROWAVE-HEATING

An apparatus was developed to quantify the degree of bumping due to th e explosion of food particulates during microwave heating. The apparat us consisted of a sound recording device, a digital storage oscillosco pe, and an electric filter. Degree of bumping for a product was define d by integration of the magnitude of an explosion over time of bumping . The sound spectrum of explosion was analyzed by Fast Fourier Transfo rm (FFT) analysis. Frequency of bumping was usually in the range 1.6 k Hz to 8 kHz. The character of microwave bumping varied according to lo calized microwave superheating effects, product formulations, and prio r heat treatment of the food.