Non-Destructive Estimation of Mechanical and Chemical Properties of Persimmons by Ultrasonic Spectroscopy

Abstract

Fruit properties, including ripeness, are still being measured destructively in most countries. Recently,<br><br>an increased attention has been given to non-destructive methods, such as ultrasonic techniques, for<br><br>quality assessment of food commodities. The aim of this study was to evaluate the feasibility of<br><br>ultrasonic spectroscopy to monitor the changes of mechanical properties (rupture force and modulus of<br><br>elasticity) and chemical properties (soluble solids content) in two cultivars of persimmons (Karaj and<br><br>Shomali) during 3 weeks of storage. Samples’ ultrasonic properties such as ultrasonic velocity and<br><br>attenuation coefficient were analyzed with transducers, and their textural properties were obtained using<br><br>destructive compression test and their refractometric properties were measured from its fresh-squeezed<br><br>juice in laboratory. Mechanical and chemical properties were statistically modeled from ultrasonic<br><br>parameters. The results showed that our proposed model could predict persimmons’ mechanical and<br><br>chemical properties well, i.e., rupture force (R2 = 0.893/0.837; RMSE = 3.683/3.849 for Shomali and<br><br>Karaj cultivars, respectively), modulus of elasticity (R2 = 0.826/0.861; RMSE = 0.231/0.217 for<br><br>Shomali and Karaj cultivars, respectively) and soluble solids content (R2 = 0.931/0.987; RMSE =<br><br>0.519/0.851 for Shomali and Karaj cultivars, respectively).