Chlorella

Botanical Profile

Chlorella is a unicellular green alga that is commonly cultivated as Chlorella vulgaris or related Chlorella species. The raw material consists of dried algal biomass containing proteins, chlorophylls, carotenoids and cell-wall polysaccharides.

Chlorella vulgaris Beijerinck is a unicellular freshwater green alga. It forms small spherical cells with chlorophyll-rich chloroplasts and is propagated industrially in open or closed cultivation systems. In commerce, other Chlorella species or strains may occur alongside Chlorella vulgaris.

The dried algal biomass is used, frequently as powder, tablets or extract. Because Chlorella is not a higher plant, its biological classification differs clearly from that of classical herbal raw materials.

For raw-material quality, strain identity, cultivation medium, drying, cell-wall disruption, protein content, chlorophyll content, heavy metals, microorganisms, toxins and residues are particularly relevant.

Botanically, or more precisely phycologically, Chlorella represents a cultivated microalgal raw material of major significance in food and biomass contexts.

Phytochemistry

Chlorella biomass contains proteins, essential and non-essential amino acids, chlorophyll a and b, carotenoids such as lutein, fatty acids, polysaccharides, nucleic acids, vitamins and minerals. The precise composition depends strongly on strain, light regime, nutrient medium and harvest time.

The green colour is determined by chlorophylls. Carotenoids and lipophilic pigments also contribute to the analytical profile. The cell wall can influence technological processing and the availability of individual constituents.

Contaminants are particularly important analytically in algal raw materials. Heavy metals, microbial contamination and foreign algae must be controlled.

Phytochemically, Chlorella is to be classified as a protein- and pigment-rich microalgal biomass, not as a classical leaf or herb drug.

Traditional Uses

Chlorella does not have a long European herbal tradition in the narrower sense, but became known primarily in the 20th century as a cultivable microalgal biomass. Its use is closely connected with modern algae cultivation, food technology and nutrient research.

In Japan, Taiwan and other regions, Chlorella developed into a widely used food and food-supplement raw material. Traditional uses in the sense of historical herbals are not the primary context.

It should therefore be classified as a modern food and microalgal use. In cultural-historical terms, Chlorella is associated more with biotechnology, protein biomass and algae production.

This distinction is important for public profiles so that Chlorella is not incorrectly presented as a classical medicinal plant.

Current Research

Current research on Chlorella addresses microalgae cultivation, biomass production, protein quality, pigments, cell-wall technology, extraction and food safety. Sustainability, circular economy and alternative protein sources are also important fields of research.

Analytical studies investigate differences among strains, cultivation conditions and drying processes. Composition can be deliberately influenced by light, nutrients and stress conditions.

Further work examines technological applications in foods, animal feed, cosmetics and biotechnological processes. Quality control and contaminant monitoring remain central topics.

Scientifically, Chlorella is a modern microalgal raw material with extensive technical and nutritional research.

Sources

• AlgaeBase: Chlorella vulgaris Beijerinck.
• PubMed literature on Chlorella vulgaris, microalgal biomass and chlorophylls.
• Scientific literature on microalgae cultivation, algal proteins and food safety.
• EFSA publications and EU legal frameworks on algal raw materials and food supplements.