Combined Effect of Dipping in Oxalic or in Citric Acid and Low O(2) Modified Atmosphere, to Preserve the Quality of Fresh-Cut Lettuce during Storage

Leaf edge browning is the main factor affecting fresh-cut lettuce marketability. Dipping in organic acids as well as the low O(2) modified atmosphere packaging (MAP), can be used as anti-browning technologies. In the present research paper, the proper oxalic acid (OA) concentration, able to reduce respiration rate of fresh-cut iceberg lettuce, and the suitable packaging materials aimed to maintaining a low O(2) during storage, were selected. Moreover, the combined effect of dipping (in OA or in citric acid) and packaging in low O(2) was investigated during the storage of fresh-cut iceberg lettuce for 14 days. Results showed a significant effect of 5 mM OA on respiration rate delay. In addition, polypropylene/polyamide (PP/PA) was select as the most suitable packaging material to be used in low O(2) MAP. Combining OA dipping with low O(2) MAP using PP/PA as material, resulted able to reduce leaf edge browning, respiration rate, weight loss and electrolyte leakage, preserving the visual quality of fresh-cut lettuce until 8 days at 8 °C.