evaluation of watermelon ripeness by analyzing sounds generated from imposed impact

one of the nondestructive methods for assessing the internal quality of some fruits is the processing and analyzing the sound signals generated by an impact on the fruit. in this regard determining the location and the suitable impact levels for a certain fruit is required. in this study, the selected crimson sweet variety of watermelon was used for the acoustic tests by imposing the impact force on samples. acoustic tests were conducted using two independent variables including impact location (two sides of the symmetrical line of watermelon and the opposite of the stem end) and impact levels (12.09, 15.08 and 17.11 kg mm s-1) on the generated sound signals, to evaluate the stiffness of the fruit. the relation between the acoustic signals and the texture of both peel and flesh was examined using puncture test. the results showed that the variation of location and levels of impact on the obtained values of acoustic tests were significant