On the quality of acoustical measures when evaluating fruits quality

In this article we show that, without any technological modification, an acoustic firmness sensor used for estimating fruits firmness, can also be used in order to discriminate between different apple varieties. A repetability and reproducibility (R&R) analysis shows that the device is capable to measure not just the mass and the resonance frequency of fruits but also some other key spectral characteristics as well. Thus, 18 key features were identified and used for the classification of apples belonging to 10 different varieties. The prospects of this study are interesting in the context of sorting automatically fruits.