Abstract:
Depending on the morphology of fruit, palmyrah (Borassus flabellifer) had been
classified in 5 types. On extraction, total carotenoid of the types from Kalpitiya was
found to vary from 3.3-9.3 mg.lnug' fresh weight. On separation by open column
chromatography using a solvent gradient, carotenoids of the 5 types of fruit were
found to vary markedly. Type Iwas dom inated by violaxanthin and neoxanthin, type
IIA by neoxanthin, ~-zeacarotene, violaxanthin and phytofluene, type lIB by
phytoene, phytofluene, violaxanthin and neoxanthin, Type III by phytoene and
violaxanthin and type IV by phytofluene and zeta-carotene. Of the nine carotenoids
isolated only ~-carotene and ~-zeacarotene are provitamin A. The 5 types gave
varying retinol equivalent 18, 155,32,21 and 33 per 100g on fresh weight basis for
types I to IV respectively. The carotenoid profile differed from those of the same
types previously collected from Mannar with the carotenoid content five to twelve
fold more in the latter, However a common feature was that lycopene and
compounds of the right fork of the carotenoid biosynthesis pathway were not
detected from all types except the uncommon type IV (found only in Kalpitiya),
indicating that the main types had a similar genetic overall biosynthetic motif. The
variation of contents of the individual components of the left fork from location to
location could be influenced by climatic and edaphic factors too. Type IV which had
considerable morphological differences appears much less related to the other
types.
