CHEMICAL ENGINEERING TRANSACTIONS VOL. 58, 2017 A publication of The Italian Association of Chemical Engineering Online at www.aidic.it/cet Guest Editors: Remigio Berruto, Pietro Catania, Mariangela Vallone Copyright © 2017, AIDIC Servizi S.r.l. I SBN 978-88-95608-52-5; I SSN 2283-9216 Improvements in Citrus Packing Lines to Reduce the Mechanical Damage to Fruit Giuseppe Manetto* a , Emanuele Cerruto a , Simone Pascuzzi b , Francesco Santoro b a Department of Agricoltura, Alimentazione e Ambiente (Di3A), University of Catania, Via S. Sofia 100, 95123 Catania, Italy b Department of Agricultural and Environmental Science (DiSAAT), University of Bari Aldo Moro, Via Amendola 165/A, 70126 Bari, Italy gmanetto@unict.it Citrus fruits destined to the fresh market are subject to several treatments in packing lines with the aim of lengthen shelf-life, increase commercial value, and comply with the rules on marketing. During the treatments, fruits collide with each other and with components of the machines and undergo mechanical damage that can be very serious. Therefore, operators make changes to the machines in order to reduce number and intensity of impacts. This paper reports the results of a study on the impacts suffered by oranges during packing operations, carried out by using an instrumented sphere IS100. Experimental measurements were conducted in a packing house equipped with two packing lines, where they were both traditional and innovative machines (regarding the empting and the filling of the bins, the release of the fruits from the sizing machines, the transfer of the fruits between belt conveyors), specifically designed to reduce the mechanical impacts to the fruits. The results showed that the innovations were effective in reducing the intensity of the impacts, expressed in terms of acceleration. The maximum acceleration was always lower (from 47 to 83 %) with respect to the conventional machines, whereas the average number of impacts per replicate was lower in the sizing machines (−6 %) and during the emptying of the bins (−36 %), but was higher during the transfer of the oranges between belt conveyors (+33 %) and during the filling of the bins (+73 %). The increase in the average number of impacts depends from the fact that the innovative systems “accompany” the fruits towards the exit, causing a greater number of impacts of lower intensity. 1. Introduction Bruising is the most common type of mechanical damage affecting fruits destined to the fresh consumption, downgrading quality and causing economic losses (Opara and Pathare, 2014). Bruising may occur during harvesting, transport, grading, packaging and it may be caused by impact, compression, abrasion, puncturing, or several actions combined (Van Zeebroeck et al., 2007; Li and Thomas, 2014). Today several technologies are available for bruise measurement and quality assessment, among which computer vision, near infrared spectroscopy, hyperspectral imaging, thermal imaging, X-rays, nuclear magnetic resonance imaging, optical measurement systems, acoustic methods, chemical sensing (Studman, 2001; Ruiz-Altisent et al., 2010; Yamakawa et al., 2012). Bruise susceptibility can be managed by controlling temperature, relative turgor, and strain rate (Baritelle and Hyde, 2001). The effects of fruit properties (size, mass, modulus of Young) and mechanical parameters (vibration frequency, acceleration amplitude, drop height) on impact damages can be investigated through Finite Element Method (FEM) simulations (Van Zeebroeck et al., 2006; Dintwa et al., 2008; Cerruto et al., 2015) or statistical approaches (Barreiro et al., 1997; Menesatti and Paglia, 2001; Bielza et al., 2003). A direct measurement of impact forces, especially during pack house operations, may be carried out by means of the so called “Instrumented Spheres” (IS), a sort of “artificial fruits” which mimic physical properties and mechanical responses of fruits and vegetables during post-harvest handling. Essentially, they are data loggers subjected to the same treatments as real products, that record mechanical stresses in terms of acceleration using accelerometers as in IS100 (Zapp et al., 1990; Ragni and Berardinelli, 2001; Di Renzo et al., 2009) and PTR 100 (or PTR 200) (Van Canneyt et al., 2003), or in terms of forces using Pressure DOI: 10.3303/CET1758066 Please cite this article as: Manetto G., Cerruto E., Pascuzzi S., Santoro F., 2017, Improvements in citrus packing lines to reduce the mechanical damage to fruit, Chemical Engineering Transactions, 58, 391-396 DOI: 10.3303/CET1758066 391