Regulation of the levels of health promoting compounds: lupeol, mangiferin and phenolic acids in the pulp and peel of mango fruit: a review.

There is a demand for feasible methodologies that can increase/maintain the levels of health-promoting phytochemicals in horticultural produce, due to strong evidence that these compounds can reduce risk of chronic diseases. Mango (Mangifera indica L.), ranks fifth among the most cultivated fruit crops in the world, is naturally rich in phytochemicals such as lupeol, mangiferin and phenolic acids (e.g. gallic acid, chlorogenic acid and vanillic acid). Yet, there is still much scope for up-regulating the levels of these compounds in mango fruit through manipulation of different preharvest and postharvest practices that affect their biosynthesis and degradation. The process of ripening, harvest maturity, physical and chemical elicitor treatments such as low temperature stress, methyl jasmonate (MeJA), salicylic acid (SA) and nitric oxide (NO) and the availability of enzyme cofactors (Mg2+ , Mn2+ and Fe2+ ) required in terpenoid biosynthesis were identified as potential determinants of the concentration of health-promoting compounds in mango fruit. The effectiveness of these preharvest and postharvest approaches in regulating the levels of lupeol, mangiferin and phenolic acids in the pulp and peel of mango fruit will be discussed. In general spray application of 0.2% iron(II) sulphate (FeSO4 ) 30 days before harvest, harvest at sprung stage, storage of mature green fruit at 5 °C for 12 days prior to ripening, fumigation of mature green fruit with 10-5  mol L-1 and/or 10-4  mol L-1 MeJA for 24 h or 20 and/or 40 µL L-1 NO for 2 h upregulate the levels of lupeol, mangiferin and phenolic acids in pulp and peel of ripe mango fruit.