Storage conditions and waxing affect water status and quality of mango.
Muy Rangel D., Siller Cepeda J., Díaz Pérez J., Valdez Torres B.
Author Affiliation: Centro de Investigación en Alimentación y Desarrollo, A.C. - Unidad Culiacán, Apdo. postal 32-A, Culiacán, Sinaloa, 80129, Mexico.
Revista Fitotecnia Mexicana 27 : 201-209
Abstract : The study determined the effect of storage conditions and waxing on the water status and postharvest quality of mango (Mangifera indica cv. Keitt) fruits. Hydrothermal treated fruits were divided on two sets: one waxed with a commercial wax (Britex), and the other unwaxed as the control. Waxed and unwaxed fruits were stored under three different water vapour pressure deficit (VPD) conditions, 1.52, 1.14 and 0.22 kPa, during 10 days at 24±1°C. Daily and cumulative weight loss, firmness, relative water content (RWC), water potential (?W), osmotic potential (?s), pressure potential (?p) and soluble solid content (°Brix) were determined. Weight loss increased directly proportional to VPD. Wax application was effective in reducing by 30% the weight loss, but only at high VPD. Using daily weight loss and DPV conditions, empiric models were generated to predict shelf life on control and waxed fruits (r2=0.90). When the fruits reached 89% RWC and ?p=0 (cellular plasmolysis), the commercial quality was still unaffected. Fruits with 84% RWC, ?p0, and firmness=20 N, defined the beginning of commercial quality loss. ?W was reduced during storage from -1.0 to -2.8 MPa, depending on VPD conditions and wax application; this reduction was partially due to solute accumulation (°Brix) that modified ?s. As °Brix increased, ?s descended in a lineal relation, a relation that can also be used for prediction.