Effect of Packaging Technology on the Quality of Pre-cooled Clementine Fruit

This paper reports the results of comparative tests using pre-cooling and an innovative packaging device on Clementine fruit (Citrus clementina Hort. ex Tan.) aiming to reduce the weight loss and to preserve fruit quality. The tests were carried out by dividing Clementine fruits into six homogeneous lots: three lots were subjected to the pre-cooling (using a cooling unit prototype) followed by controlled temperature storage (6 ± 0.5 °C, RH 90–95%), three lots were directly stored in cold storage room without pre-cooling. Moreover, in order to verify the effect on fruit weight loss, traditional HDPE bags and the same bags improved with an innovative breathable device were used for the packaging. To evaluate the effect of the treatments were used: fruit weight, peel and pulp colour, deformation, firmness, juice yield, total soluble solids content, pH and titratable acidity. After 15 and 30 days of cold storage, plus 7 days of shelf-life, were assessed: VOC, O2 and CO2 concentration inside the packaging, weight loss, decay incidence and physiological disorders. Results showed that during the storage using HDPE bags the fruit weight loss, chilling injury and ageing were significantly reduced with respect to unwrapped fruit. However, a higher presence of total decay was observed in all wrapped fruit, although it was absent on precooled fruit, up to 15 days of cold storage. Precooling reduced significantly ethylene production inside packaging.