- A high molecular weight polysaccharide built up of d-glucose residues in α-1,4 linkage, differing from cellulose in the presence of α- rather than β-glucoside linkages, that exists in most plant tissues; converted into dextrin when subjected to the action of dry heat, and into dextrin and d-glucose by amylases and glucoamylases in saliva and pancreatic juice; used as a dusting powder, an emollient, and an ingredient in medicinal tablets, and is an important raw material for the manufacture of alcohol, acetone, n-butanol, lactic acid, citric acid, glycerine, and gluconic acid by fermentation; chief storage carbohydrate in most higher plants. SYN: amylum. [A.S. stearc, strong]- rice s. rice product used as a supplement in many media formulations used for the culture of intestinal protozoa ( e.g., Entamoeba histolytica).- soluble s. a high molecular weight, water-soluble dextrin produced by the partial acid hydrolysis of s.; useful in iodimetry, as it gives an easily visible purple-black end point in the presence of free iodine.
* * *starch 'stärch n a white odorless tasteless granular or powdery complex carbohydrate (C6H10O5)x that is the chief storage form of carbohydrate in plants, is an important foodstuff, has demulcent and absorbent properties, and is used in pharmacy esp. as a dusting powder and as a constituent of ointments and pastes
* * *n.the form in which carbohydrate are stored in many plants and a major constituent of the diet. Starch consists of linked glucose units and occurs in two forms, a-amylose and amylopectin. In a-amylose the units are in the form of a long unbranched chain; in amylopectin they form a branched chain. The presence of starch can be detected using iodine: a-amylose gives a blue colour with iodine; amylopectin a red colour. Starch is digested by means of the enzyme amylase. See also dextrin.
* * *(stahrch) [A.S. stercan to stiffen] any of a group of polysaccharides of the general formula (C6H10O5)n, composed of a long-chain polymer of glucose in the form of amylose and amylopectin; it is the chief storage form of energy reserve (carbohydrates) in plants. [NF] a preparation consisting of the granules separated from the mature grain of corn or wheat, or from potato tubers, occurring as irregular, angular, white masses or fine powder; used as a dusting powder and as a filler, binder, and disintegrant in pharmaceutical preparations.
Medical dictionary. 2011.