Results
3.1. Resonance frequency The first set of experiments, for all the test materials, was to determine the frequency with the highest magnitude of acceleration of vibration. The results from 1-D FFT plot were similar for all the tested products, with the resonance frequency for the mixing system determined at approximately 20 Hz, as can be observed from the following 1-D FFT plot for cheese sauce(Fig. 3). Based on the results from the 1-D FFT plots, 20 Hz was the frequency with the highest magnitude of acceleration fol-lowed by 30 Hz, where the acceleration magnitude was slightly lower. For that reason, the tested frequencies were selected close to the resonance frequency, within the range of 16–30 Hz.