Nutritional Properties, Antioxidant Activity, and Heavy Metal Accumulation in Selected Marine Macro-Algae Species of Sri Lanka

Abstract

In recent years, the emergence of drug resistance and sensitivity in leading diseases has heightened global interest in natural nutraceuticals as primary health supplements. However, comprehensive scientific scrutiny is essential before marketing these as supplements. In this study, we assessed the nutritional composition, antioxidant activities, and trace metal accumulation in eleven selected Sri Lankan coastal seaweed species. Gracilaria corticata had the highest (p Ulva rigida displaying the highest (p Cladophora herpestica having the highest (p Sargassam cinereum, Turbinaria ornata and Sargassum crassifolium had the highest (p p p < 0.05) accumulated metal in seaweeds compared to other metals. Toxic heavy metals, such as arsenic, cadmium and chromium, levels in all of the studied seaweeds surpassed the WHO limits. While seaweeds displayed acceptable nutritional and antioxidant properties, heavy metal presence poses a potential health risk to consumers. Products using seaweeds with accumulated heavy metals may have lower nutritional quality. Thus, this study underscores the need for comprehensive scientific investigation before developing high-quality natural food products or supplements from seaweeds.

Keywords

• seaweeds
• nutrition
• antioxidant activity
• heavy metals
• trace elements