Post-harvest nitric oxide treatment reduces chilling injury and enhances the shelf-life of mango (Mangifera indica L.) fruit during low-temperature storage

Abstract

SummaryLow-temperature storage is an effective and commercial means to extend the shelf-life of fresh fruit. However, tropical and sub-tropical fruit are prone to chilling injury (CI) while stored at low-temperatures. Among these, mango (Mangifera indica L.) is highly susceptible to CI when stored below 13ºC. The objective of this study was to determine the effect of a dipping treatment in 1.0 or 1.5 mM sodium nitroprusside (SNP) on the incidence of CI and selected quality traits in mango (M. indica L. ‘Chausa’). Freshly-harvested, physiologically mature mango fruit were treated with the nitric oxide (NO)-donor, sodium nitroprusside (at 1.0 mM or 1.5 mM), by the immersion method, followed by storage at 8º ± 0.5ºC and 90 ± 5% relative humidity for 30 d. Before recording the effects, fruit were exposed to 25º ± 2ºC for 3 d to simulate shelf-life. The results indicated that dipping in SNP, irrespective of concentration, reduced the incidence of CI by 1.5- to 1.7-fold, electrolyte leakage by 26 – 41%, the rate of respiration by 47 – 59%, and the rate of ethylene production by 117 – 270% compared to control fruit dipped in distilled water. Furthermore, 1.5 mM SNP maintained a lower fresh weight loss (46%), a lower incidence of decay (220%), reduced pectin methyl esterase (81%) and polygalacturonase (30%) activities, and higher fruit firmness by 43% compared to control fruit. Electrolyte leakage was highly correlated with CI (r = 0.982), while fruit firmness showed a negative correlation with CI. These findings confirmed that 1.0 mM or 1.5 mM SNP can be used as a dipping treatment before low temperature storage of mango fruit to prolong its shelf-life and maintain its quality.