Application of calcium–boron improve fruit quality, cell characteristics, and effective softening enzyme activity after harvest in mango fruit (Mangifera indica L.)

Increasing demand for high quality mangoes has increased the need for enhanced fruit quality and longer shelf life. The concentrations of calcium (Ca) and boron (B) in fruit can affect its quality and shelf life and physiochemical composition. However, these effects have not been investigated in postharvest mango. The effects of Ca and B concentration on mango fruit quality and shelf life were investigated by spraying a 40% Ca(NO3)2·4H2O and 0.3% H3BO3 solution at 1, 2, 3 and 4 mL L−1 concentration on mango fruits for 60 and 90 days after anthesis compared with water control treatment. Mango fruits were subsequently harvested 110 days after anthesis and stored at 15 °C. Chemical and physical properties were then observed every three days. When fruit were sprayed with a 1 mL L−1 Ca–B solution, the size of the mango fruit and cells in the exocarp and the mesocarp increased, which was increased concentrations of Ca and B in the fruit. In addition, we found that pre-harvest application of Ca and B by spraying improved the tissue structure of the segment membrane, as well as increased fruit firmness, which was consistently delayed as much as nine to 21 days after harvest. Moreover, fruit that had been sprayed with a 1 mL L−1 Ca and B solution had an extended storage life at 15 °C of 24 days. Vitamin C concentration and SS/TA were higher at this treatment concentration compared to the other treatments. Furthermore, Hunter L, a, and b values of the peel were lower than those from fruit in other treatments groups. Additionally, the activities of pectin methylesterase and polygalacturonase in the treated pulp were reduced.