Mucilage is sulphuric acid esters of complex polysaccharides and water extraction products from seed coat, plant root hair, sea weeds etc. They contain galacturonic acid and some sugars. e.g. Agar agar, alginic acid.
Occurrence of Mucilage:
They occur in seed coat of certain plant species. e.g. Linseed, flax mustard etc and some sea weeds
Chemical Nature of Mucilage:
1. They are chemically complex polysaccharides, consisting of branched chain structure of uronic acid (galacturonic acid) and some sugar residues.
2. Naturally combined with proteins and cellulose.
3. They appear to be sulphuric acid esters of galactose.
Properties of Mucilage:
Absorb large quantity of water, swell, colloidal in nature; do not form gel, soluble inorganic solvent.
Physiological Role of Mucilage:
They absorb large quantity of water and hold water in plant tissue. They help to retain moisture and used for seed germination.
1. AGAR AGAR
a) It is prepared from various species of Gelidium, Asiatic sea weeds and red algae by extracting with water.
b) It is chemically composed of sulphuric ester of linear galactan.
2. ALGINIC ACID (Sodium alginate):
a) It is extracted from sea weeds (Macrocystis, Laminaria and fucus) with Na2CO3.
b) It contains polyuronic acid. On hydrolysis gives cellulose, uronic acid,mannuronic acid.
Uses of Mucilage:
As demulcents, laxative, emulsifying agent, adhesive; useful in medicine and food industry