From Pond to Plate: Safety Perspectives on Algae in Food and Feed Systems

Algae, ranging from microscopic microalgae to macroscopic seaweeds, represent one of the most promising bio-resources for the twenty-first century. Found in freshwater, brackish, and marine ecosystems, algae are rich in essential nutrients, including proteins, lipids, carbohydrates, vitamins, minerals, pigments, and bioactive compounds. These diverse biochemical constituents make them valuable for direct human consumption as functional foods and nutraceuticals, and as feed additives for fish, poultry, and livestock. Owing to their rapid growth rate, minimal land requirement, and ability to utilize wastewater or saline water, algae are a sustainable alternative to conventional crops. However, the safety and non-toxicity of algal species must be ensured before their large-scale incorporation into food and feed chains. This chapter reviews the nutritional profiles and safety aspects of selected seaweeds, viz., Porphyra, Laminaria, Caulerpa, Hizikia fusiforme, Gracilaria vermiculophylla, G. edulis, G. verrucosa, Acanthophora specifera, Ulva, Undaria pinnatifida, Cladophora, Ascophyllum nodosum, Fucus, Palmaria palmata, and Enteromorpha prolifera and microalgae such as Dunaliella salina, Haematococcus pluvialis, Nannochloropsis, Tetraselmis, Spirulina, and Chlorella. Studies indicate that eight seaweed species (Porphyra, Laminaria, Caulerpa, Hizikia fusiforme, Gracilaria vermiculophylla, G. edulis, G. verrucosa, and Acanthophora specifera) have shown potential toxic effects in humans when consumed excessively, while Porphyra has also been reported to cause toxicity in animal feed. Data on the safety of microalgae are limited but generally suggest low toxicity, with Spirulina and Chlorella Generally Recognized as Safe (GRAS) species. Despite this, contamination with heavy metals, persistent organic pollutants, or harmful algal metabolites can pose potential risks. Hence, systematic safety evaluation, species authentication, and adherence to food safety standards are essential before commercialization. The chapter emphasizes the need for toxicological validation, monitoring of cultivation environments, and harmonized regulatory frameworks to ensure consumer safety and promote algae-based food and feed industries.