Determination of carotenoids in two algae species from the saline water of Kapulukaya reservoir by HPLC

Abstract

The local algae species, Chlorella vulgaris and Scenedesmus regularis, from a highly saline water body of Kapulukaya Reservoir were isolated to analyze their carotenoid composition and content using HPLC method. The gradient solvent system of methanol-acetonitrile-water (84:14:2, v/v/v) and methylene chloride (100%), used to resolve a range of carotenoids from the saponified cells, proved an acceptable separation as inferred from the retention factor (k) ranging between 0.75 and 7.76 and the separation factor (alpha) values greater than 1. Resolution peaks assigned to carotenoids, 21 for C. vulgaris extracts and 22 for S. regularis extracts, were reached within the duration time of 45 min. Main carotenoids identified either tentatively or positively were all-trans-lutein, 9- or 9'-cis-lutein, 13- or 13'-cis-lutein, cis-lutein, All-trans-alpha-carotene, 9- or 9'-cis-alpha-carotene, All-trans-beta-carotene, 9- or 9'-cis-beta-carotene in the species except for all-trans-beta-cryptoxanthin found only in S. regularis. Auroxanthin, neochrome, neoxanthin, and cis-neoxanthin were identified as epoxy-containing compounds. Quantitatively, C. vulgaris was distinguished to have greater amount of lutein and cis-isomers (2.74 mg/g), 77.89% while S. regularis was predominated by beta-carotene and cis isomers as major component, being 80.72% (5.76 mg/g) in total carotenoids (TC). In terms of total carotenoids, the species were considered to be efficient sources for further practical applications.