Identification of innovative potential quality markers in rocket and melon fresh-cut produce Marina Cavaiuolo a , Giacomo Cocetta b , Roberta Bulgari b , Anna Spinardi b , Antonio Ferrante b,⇑ a Institut de Biologie Physico-Chimique, 13 Rue Pierre et Marie Curie, 75005 Paris, France b Department of Agricultural and Environmental Sciences, Università degli Studi di Milano, via Celoria 2, Milano 20133, Italy article info Article history: Received 17 February 2015 Received in revised form 28 April 2015 Accepted 30 April 2015 Available online 1 May 2015 Chemical compounds studied in this article: Chlorophyll (PubChem CID: 6477652) Sucrose (PubChem CID: 5988) Glucose (PubChem CID: 53782692) Fructose (PubChem CID: 53782691) Galactose (PubChem CID: 439357) Ethylene (PubChem CID: 6325) Ascorbic acid (PubChem CID: 54670067) Malondialdehyde (PubChem CID: 10964) Superoxide anion (PubChem CID: 5359597) Hydrogen peroxide (PubChem CID: 784) Keywords: Abiotic stress Fresh-cut vegetables Postharvest Production chain Senescence abstract Ready-to-eat fresh cut produce are exposed to pre- and postharvest abiotic stresses during the produc- tion chain. Our work aimed to identify stress responsive genes as new molecular markers of quality that can be widely applied to leaves and fruits and easily determined at any stage of the production chain. Stress responsive genes associated with quality losses were isolated in rocket and melon fresh-cut pro- duce and their expression levels analyzed by quantitative real time PCR (qRT-PCR) at different time points after harvest at 20 °C and 4 °C. qRT-PCR results were supported by correlation analysis with phys- iological and biochemical determinations evaluated at the same conditions such as chlorophyll a fluores- cence indices, total, reducing sugars, sucrose, ethylene, ascorbic acid, lipid peroxidation and reactive oxygen species. In both species the putative molecular markers increased their expression soon after harvest suggesting a possible use as novel and objective quality markers of fresh-cut produces. Ó 2015 Elsevier Ltd. All rights reserved. 1. Introduction Ready-to-eat (RTE) fresh cut fruits and vegetables are minimally processed produce that are used for a direct consumption and do not undergo further washing or cooking. Because of their charac- teristics RTEs are very convenient and respond to the changing life- styles and eating habits of the consumers world-widely. RTEs are fresh and nutritious food that contribute to a healthy balanced diet and represent a good and rather cheap source of vitamins, minerals and antioxidants (Alarcón-Flores, Romero-González, Vidal, & French, 2014). As consequence the production of RTEs showed a positive trend in the market over the last two decades: currently, the fresh-cut salads cover about the 50% of the market volume, fresh-cut fruits account for more than 10% of the share and other fresh-cut vegetables (e.g. crudité, soup mix, stir-fry vegetables) cover the remaining 40%. The quality of RTEs is defined by sensory characteristics (appearance, aroma, firmness and taste) and nutritional value (Watada & Qi, 1999), parameters that must be preserved during postharvest. However, RTEs are constituted by metabolizing living cells and their shelf-life is limited to few days or a week. Hence, a better comprehension of the physiological, biochemical and molec- ular mechanisms that control postharvest life in RTEs is pivotal to maintain effectively the quality throughout the supply chain and to reduce losses. It was shown that temperature, storage time, wounding, relative humidity and atmosphere composition affect the rate of quality degradation and the shelf-life of the final pro- duce (Pirovani, Piagentini, Guemes, & Pentima, 1998) and, particu- larly, abiotic stresses contribute to quality losses (Crisosto & Mitchell, 2002). http://dx.doi.org/10.1016/j.foodchem.2015.04.143 0308-8146/Ó 2015 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. E-mail address: antonio.ferrante@unimi.it (A. Ferrante). Food Chemistry 188 (2015) 225–233 Contents lists available at ScienceDirect Food Chemistry journal homepage: www.elsevier.com/locate/foodchem