Comparison of major carotenoid composition in palm fruits (Arecaceae): An analysis of oil palm fruits and the colored exocarp fruits of four palm species

The oil palm, a widely studied species of palm, is a crucial source of edible oil and pro-vitamin A carotenoids, primarily α- and β-carotene. The diverse peel and pulp colors (yellow-orange-red) of various palm fruits suggest the presence of not only pro-vitamin A carotenoids but also other bioactive carotenoids like lutein and lycopene, which offer additional health benefits. This study aimed to identify and quantify the major carotenoids in fruits with colored exocarps of four varieties of palm species belonging to different genera and compare them to those in oil palm fruit to evaluate their bioactive potential for human health. High-performance liquid chromatography and mass spectrometry were used for chromatographic and spectrometric analyses using non-saponified samples, except for lutein estimation, revealing four major carotenoids: α- and β-carotene, lycopene, and lutein, which together accounted for more than 50% of the total carotenoid content. Among the five palm fruits tested (MacArthur, Manila, mountain date, foxtail, and oil palms), foxtail palm exhibited the highest concentration of major carotenoids at 500 µg/g dry weight (d.w.), with β-carotene comprising 69% of this total, followed by MacArthur palm (235 µg/g d.w.), whereas mountain date palm had the lowest concentration of major carotenoids at 135 µg/g d.w. These findings suggest that colored palm fruits are significant sources of both pro-vitamin A carotenoids and other beneficial carotenoids like lycopene and lutein. The method of sample preparation, particularly the inclusion or omission of a saponification process, plays a critical role in the recovery and accurate quantification of carotenoid concentrations due to their varying susceptibility to this process.