Some Studies on the Flabelliferins and Carotenoids of the Fruit Pulp of Palmyrah (Borassus flabellifer L)

Abstract

In studies directed at understanding fully, the options for utilization of palmyrah fruit pulp (PFP), the work reported here was concentrated on f1abelliferins (saponins of B-sitosterol) and carotenoids. Flabelliferins, F-l1, Fb, Fc and Fd which were purified by solvent-gradient chromatography were subjected to naringinase hydrolyses at pH=4.0 (/3 rhamnosidase activity). The analysis of products of hydrolysis indicated that the bitter f1abelliferin (F-ll) had a straight chain carbohydrate moiety of sequence Rha. Glu. Glu. Rha. The antimicrobial f1abelliferin FB' had, as proved by previous studies, a branched carbohydrate moiety with 2-rhamnose terminii linked to glucose, at least one of which had a /3anomeric carbon. This was further confirmed by subjecting F8 to the action action of fermenting yeast. Fe did not contain /3rhamnose anomeric bonds. The two rhamnoses were probably linked. FD' a diglycoside containing glucose and rhamnose, contained /3rhamnose terminus as proved by previous spectroscopic studies. Flabelliferins of PFP were stable to temperatures of less than 75°C over a period of 6 hours but were hydrolysed by fermenting yeast, which results in a lowering of bioactivity f1abelliferins in products like wines. The carotenoids of Amax of 443,427,470,400 wre shown to be the following carotenoids: a carotene, /3-zeacarotene, lycopene, and <;-carotene, Only the first two named are structurally pro-v it A. Treatment to mimic alcoholic fermentation and recovery of a distilled spirit results in loss of pro-vitamin A carotenoids that become oxygenated and give a deepening of colour. As a result the pigment can only be utilized as a colouring material after fermentation.