Identification and HPLC quantification of carotenoids of the fruit pulp of Chrysophyllum roxburghii

Abstract

Carotenuids of the fruit pulp of Chrysophyllum roxburghii (Sinhala: lavalu) amounted to about 180 mgkg-1 by fresh weight. The carotenoids were isolated by open column chromatography (MgO:Celite 1:1) using mixtures of petroleum ether 40-60°C and acetone and identified by UV/visible spectra, chemical tests, and High Performance Liquid Chromatography (HPLC) using authentic standards and a photodiode array detector (PAD). The major carotenoid was trons-violaxanthin (113 mgkg-1). Also present was cisviolaxanthin, neoxanthin, β-cryptoxanthin monoepoxide, lutein, β-cryptoxanthin, ζ-carotene and β-carotene. The retinol equivalent of the pulp was only 68 RE/100 g. The study shows that Chrysophyllum roxburghii is not a good source of provitamin A. Further as violaxanthin is reported to be not absorbed by humans, it is of no use as a dietary antioxidant. However, as trans-violaxanthin can be obtained in quantity in the pure crystalline state, directly from the column and has the benefit of eluting at 20% acetone away from most carotenoids. the compound will be useful as a standard for HPLC analysis of carotenoids from other fruits and leaves.