The carotene, carotenoid and chlorophyll contents of some Scottish seaweeds

Abstract

AbstractSome species of brown, green and red seaweeds collected in south‐east Scotland have been analysed for carotene, total xanthophylls (other than fucoxanthin) and total chlorophyll. A land plant, the common dockweed, was analysed for comparison. Carotenoids were extracted from the saponified samples with ethanol and light petroleum, and estimated by absorptiometry in a Unicam spectrophotometer. Carotene was isolated from xanthophylls by chromatography on alumina and determined separately. Total chlorophyll was measured similarly, at the point of maximal absorption in the red region of the spectrum, in a methanol extract of the plant material. In the brown algae, carotene was found to be usually more abundant than xanthophylls. The red and green algae resembled land plants in having less carotene than xanthophylls. Ratios of xanthophylls to carotene and of total chlorophyll to total carotenoids in brown, green and red algae were similar to ratios calculated from the data of Seybold & Egle, though the concentrations of both green pigments and carotenoids were less in the present samples than in species of the same name examined by Seybold & Egle. It is concluded that, like land plants, marine algae contain amounts of carotenoids that are related much more nearly to the amount of chlorophyll than to the major constituents of the plant's dry matter.