Algae

A heterogeneous group of unicellular and multicellular eukaryotic photosynthetic organisms, mostly aquatic — spanning single-celled microalgae to giant kelps. Certain algae are harvested commercially for thickeners: agar, alginates and carrageenans come from seaweeds, while microalgae supply single-cell protein, vegetarian omega-3 oils and pigments. A few species produce potent toxins that cause food poisoning via contaminated fish and shellfish, so species identification and sourcing controls are essential safety steps. Algae are simultaneously ancient foods, modern ingredients and occasional hazards. Their study spans ecology, food technology, nutrition and toxicology in equal measure.