Modified atmosphere packaging for shelf life extension of fresh-cut apples

• The influence of MAP on ethylene, firmness, browning and off-flavor is discussed.
• Potential benefits of using alternative gases such as Ar and N2O are reviewed.
• The interaction between anti-browning treatment and MAP is debated.
• The case-study of Stayfresh project is contextualized.

Processing steps, such as cutting and peeling, increase the respiration rate and ethylene production of apples, quickening senescence phenomena with effects on texture, color and flavor. Modified atmosphere packaging (MAP) and antioxidant pre-treatments are used to control the decay of fresh-cut apples during shelf life. MAP has become a widely used food preservation technique as it minimally affects fresh product characteristics. The purpose of this paper was to discuss the influence of conventional (O2, N2 and CO2) and alternative (Ar and N2O) MAPs as well as the interaction between anti-browning treatment and MAPs on ethylene production, firmness, browning, off-flavor and sensory characteristics, contextualizing the results obtained in a case study on ‘Golden Delicious’ apple slices developed within the Stayfresh project. The packaging under conventional modified atmospheres, characterized by low O2 level (1 and 5%), and the alternative mix Ar + CO2 successfully preserved the firmness of apple slices during all refrigerated storage limiting the ethylene production, even if the preserving efficacy of MAP resulted almost completely nullified by the dipping treatment, which caused a structural breakdown. MAPs were not able to control the enzymatic browning if not combined with an anti-browning dipping treatment. It was highlighted the key role of sensory analysis in finding the best combination between MAP, anti-browning treatment and shelf life time. The contrasting results among the various research groups could be reasonably also due to the different periods and temperatures of shelf life.