Mucilage is a compound synthesized by plants and microbes. It swells in water and has a gelatinous consistency. Its function is to maintain a moist environment.
Mucilage forms a heterogeneous group of biopolymers, which are mainly composed of polysaccharides. Its main property is the ability to absorb water and thus to form mucus colloids and gels (so-called hydrocolloids). A distinction is made between animal mucilage consisting of glycoproteins and plant-based mucilage, which is almost exclusively formed from hetero polysaccharides. Furthermore, the mucilage substances are divided into water-soluble and water-insoluble substances. Plant-based mucilage occurs in grains, but also in roots, bark, stalks and leaves of higher plants as well as in algae. Flax seed, legumes and tamarind mucilage are especially known.