Series No. 1 Identification and HPLC Quantification of Carotenoids of the Fruit Pulp of Chrysophyllum Roxburghii

Abstract

Carotenoids of the fruit pulp of Chrysophyllum roxburghii (Sinhala: laualu) amounted to about 180 mgkgl by fresh weight. The carotenoids were isolated by open column chromatography (Mg0:Celite 1:l) using mixtures of petroleum ether 40-60 C and acetone and identified by UVIvisible spectra, chemical tests, and High Performance Liquid Chromatography (HPLC) using authentic standards and a photodiode array detector (PAD). The major carotenoid was trans-violaxanthin (113 mgkg-'1. Also present was cis- violaxanthin, neoxanthin, P-cryptoxanthin monoepoxide, lutein, p-cryptoxanthin, <-carotene and p-carotene. The retinol equivalent of the pulp was only 68 RE1100 g. The study shows that Chrysophyllum roxburghii is not a good source of pro- vitamin 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. hydroxy sintaxanthin. Some of these are not listed in a recent compendium on carotenoids naturally occurring in plant^.^ Further, the experimental techniques and identification procedures used in the above study are not in line with modern analysis procedures. There is, therefore, a possibility that some of these are artifacts of isolation.