Combined Effect of Dipping in Oxalic or in Citric Acid and Low O2 Modified Atmosphere, to Preserve the Quality of Fresh-Cut Lettuce during Storage

Bernardo Pace; Imperatrice Capotorto; Michela Palumbo; Sergio Pelosi; Maria Cefola

doi:10.3390/foods9080988

Combined Effect of Dipping in Oxalic or in Citric Acid and Low O₂ Modified Atmosphere, to Preserve the Quality of Fresh-Cut Lettuce during Storage

Foods. 2020 Jul 24;9(8):988. doi: 10.3390/foods9080988.

Authors

Bernardo Pace¹, Imperatrice Capotorto¹, Michela Palumbo^{1

2}, Sergio Pelosi¹, Maria Cefola¹

Affiliations

¹ Institute of Sciences of Food Production, National Research Council of Italy (CNR), c/o CS-DAT, Via Michele Protano, 71121 Foggia, Italy.
² Department of Science of Agriculture, Food and Environment, University of Foggia, Via Napoli 25, 71122 Foggia, Italy.

Abstract

Leaf edge browning is the main factor affecting fresh-cut lettuce marketability. Dipping in organic acids as well as the low O₂ 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 O₂ during storage, were selected. Moreover, the combined effect of dipping (in OA or in citric acid) and packaging in low O₂ 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 O₂ MAP. Combining OA dipping with low O₂ 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.

Keywords: Lactuca sativa L.; minimally processed lettuce; modified atmosphere packaging; oxalic acid; shelf life.