Comparison among different postharvest ripening treatments based on carotene contents in mango using UV–VIS and Raman spectroscopy

Abstract

The overall purpose of this research work is to investigate carotenoids content using spectrophotometric data of two famous cultivars of Pakistani mangoes (Ratol and Chaunsa) under different postharvest ripening treatments. The UV–VIS absorption results of these cultivars show absorption at wavelength positions 425, 446 and 467 nm which correspond to carotenoids specifically to β-carotene. In fruits and particularly in mangoes, synthesis of β-carotene is correlated with the ripening. Overall, every treatment has shown ripening of mango, but the concentration of β-carotene based on UV–VIS absorption intensity varies with treatment as well as with cultivars. Apart from trace elements (calcium arsenide and calcium phosphide) which are injurious to human health, these results show that in both cultivars, the synthesis of β-carotene is maximum when mangoes are ripened with calcium carbide. Additionally, these results also depict the difference in the content of these important pigments more than twice in Ratol cultivar when compared with Chaunsa. Agreeing with the results of UV–VIS absorption, Raman spectroscopy also shows comparable variations in β-carotene content for both mango cultivars. The Raman spectra of pulp, under different postharvest treatments, depict β-carotene specific characteristic peaks at 1003, 1150 and 1515 cm−1. In order to educate consumers regarding good quality foods, future study with more attention focused on studying the concentration of β-carotene in other varieties is also desirable.