Modified Atmosphere Packaging of Sweet Cherries with different packaging systems: effect on organoleptic quality

Using biodegradable polymers for packaging is an alternative to synthetic inert polymers and a possible, partial solution to the problem of accumulation of solid waste. In this study was assessed the influence of two different packaging systems (biodegradable packaging and traditional packaging) on quality loss of sweet cherries cv Black Star*. In particular, the fruits were packaged in two different baskets, sealed with two distinct films. The packaging systems were: 1. Polylactic acid (PLA) basket thermo-sealed with biodegradable film (Mater-Bi®) 2. Polypropylene basket thermo-sealed with polypropylene film (control). Cherry quality during storage (35 days; 4°C) was determined by monitoring headspace gas concentration, color (L* and Hue angle), weight loss, firmness, total soluble solids, titratable acidity, Anthocyanins content, phenolics content, total antioxidant capacity and incidence of post harvest diseases. Results suggest that biodegradable polymers could be used in packaging of sweet cherries without negative effects on final quality. During storage, an increase in CO2 and decrease in O2 concentration occurred inside the MAP packages, reaching a steady-state atmosphere after 14 days (Control: 0.2% O2; 28% CO2) or 21 days (PLA: 0.2% O2; 31.5% CO2). Firmness loss and color trends were the same for all samples. Total soluble solids content was substantially unchanged from the beginning to the end of storage almost no statistically significant differences between the two packaging systems while the incidence of post harvest diseases was almost always lower in sample packaged with biodegradable polymers probably as a consequence of high CO2 level. In conclusion, cherries are particularly suitable to MAP and good results are usually obtained with traditional packaging associated with MA, while the biodegradable polymers are suitable as a packaging material for storage without reducing fruit quality.