Effect of different coating treatments on the quality of mango fruit

Eight coating formulations were evaluated for beneficial effects on the shelf-life of mangoes (cvs. Kent, Tommy Atkins, and Lirfa) harvested at different maturity stages. Four coatings were then selected for further study under various conditions of storage including ambient (19-22C and 56-60% RH) and simulated commercial (12C and 80% RH) storage. The four coating formulations contained carnauba wax, shellac, zein, and/or cellulose derivatives. All coatings reduced the respiratory rate, the development of external and internal color, and all but carnauba wax retarded the loss of firmness. Changes in acids were also delayed in all coated mangoes. Based on these parameters, fruit maturation was estimated to have been delayed by a few days compared with uncoated fruit. Shellac and cellulose-based coatings, however, caused elevated levels of ethanol, although this did not lead to significant flavor differences from the control (uncoated fruit) in sensory tests. Only the carnauba wax coating was an effective water loss barrier under conditions of high RH.