CHEMICAL ENGINEERING TRANSACTIONS VOL. 44, 2015 A publication of The Italian Association of Chemical Engineering Online at www.aidic.it/cet Guest Editors:Riccardo Guidetti,Luigi Bodria, Stanley Best Copyright © 2015, AIDIC ServiziS.r.l., I SBN 978-88-95608-35-8; I SSN 2283-9216 Post-harvest UV-C and PL Irradiation of Fruits and Vegetables Gianpiero Pataro* a , Giorgio Donsì b,c , Giovanna Ferrari a,c a Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132 - 84084 - Fisciano (SA), Italy b b Department of Computer Science, University of Salerno, Via Giovanni Paolo II, 132 - 84084 - Fisciano (SA), Italy c ProdAl scarl, University of Salerno (Italy), Via Ponte don Melillo, - 84084 - Fisciano (SA), Italy gpataro@unisa.it The exposure to UV-C and Pulsed Light (PL) light causes stress in plant tissues, which stimulates the biosynthesis of defensive secondary metabolites with antimicrobial and antioxidant activity. For this reason, recent studies have examined the capability of UV-C and PL as effective methods to prolong the fresh status as well as preserve or even improve the content and activity of antioxidant compounds of fresh produce through post-harvest handling and processing. In this work, the effect of PL and UV-C treatments on quality and antioxidant properties of tomatoes and Annurca apples intended for fresh consumption was investigated. Fruits harvested at the green stage were exposed to both light treatments at energy dosages of 2 and 4 J/cm 2 . Treated and untreated samples were allowed to ripen under day/night cycles illumination conditions at room temperature for up to 21 days for tomatoes and 28 days for apples. The effects of light treatments on the colour, pH, titratable acidity and °Brix as well as on the levels of lycopene, total carotenoids, total phenolic compounds and antioxidant activity, were evaluated through storage and compared with those of untreated samples. Results indicate that pH, titratable acidity and °Brix of all fruit samples were not significantly affected by light treatments and remained almost the same throughout storage. The skin colour of untreated and exposed fruits changed during storage period, with no appreciable influence of the light treatments. However, the exposure of apples and tomatoes to light treatments enhanced the antioxidant properties of these fruits during storage. These results suggest that post-harvest PL and UV-C irradiation can be utilized to the health value of tomatoes and Annurca apples by increasing the level of certain bioactive compounds without inducing significant changes to their physical properties during storage. 1. Introduction Fruits and vegetables play a significant role in human nutrition for their richness in health-related food components with antioxidant activity. Among vegetables typically consumed by humans, tomatoes represent an important source of many traditional nutrients and are a particularly rich source of several carotenoids (Jegadeesh et al., 2011). Carotenoids, are largely accumulated in tomato during fruit ripening by the degradation of green pigment chlorophyll and the transformation of chloroplast into chromoplast during the lag phase that precedes maturation. Within the class of carotenoids, lycopene is the most abundant and largely influence the quality perception of fresh tomatoes being it is responsible for the characteristic red colour of ripe tomatoes. This compound has notable antioxidant activity and several studies have been done to evaluate its anticancer activity, in particular against prostate cancer (Giovannucci 1999). In addition to carotenoids, tomatoes are also an effective way to supply other natural antioxidants such as ascorbic acid and phenolic compounds, namely flavonoids and phenolic acids (Jegadeesh et al., 2011), which, in turn, are characterized by health beneficial properties such as antiinflammatory, antihistaminic, and antitumor activities. DOI: 10.3303/CET1544006 Please cite this article as: Pataro G., Donsi G., Ferrari G., 2015, Post-harvest uv-c and pl irradiation of fruits and vegetables, Chemical Engineering Transactions, 44, 31-36 DOI: 10.3303/CET1544006 31