Levels of terpenoids, mangiferin and phenolic acids in the pulp and peel of ripe mango fruit influenced by pre-harvest spray application of FeSO4 (Fe2+), MgSO4 (Mg2+) and MnSO4 (Mn2+)

Fe²⁺, Mg²⁺ and Mn²⁺ are enzyme cofactors in terpenoids biosynthesis. Effects of pre-harvest spray of FeSO₄, MgSO₄ and MnSO₄ (0.2% and 0.3%) 30 d prior to harvest on the levels of terpenoids and phenolic compounds in ripe mango fruit were investigated. All treatments significantly increased lupeol in the peel compared to control and it was highest in pulp of 0.3% FeSO₄-treated fruit. Spray of each nutrient (0.3%) increased total carotenoids in the pulp. Mangiferin in pulp was significantly higher in the fruit treated with 0.2% FeSO₄, MgSO₄ and MnSO₄ compared to control and 0.3%. Concentrations of gallic, ferulic and caffeic acids in the peel and chlorogenic acid in pulp and peel were highest in fruit sprayed with 0.2% FeSO₄. In conclusion, pre-harvest spray of FeSO₄, MgSO₄ and MnSO₄ regulates concentrations of terpenoids and phenolic compounds in the pulp and peel of ripe mango fruit.