amylopectin


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amylopectin

[‚am·ə·lō′pek·tən]
(biochemistry)
A highly branched, high-molecular-weight carbohydrate polymer composed of about 80% corn starch.
References in periodicals archive ?
Further investigations are required to elucidate the coordinated action of multiple key enzymes in starch synthesis at high temperature and their relations to amylopectin fine structure and rice quality.
However, ZHOU & KAPLAN (1997), evaluating the digestibility of two starch sources, potato with 70-75% amylopectin and maize with 70% amylose, in an experiment with rats during four weeks, also observed significantly greater feed intake with the high amylopectin diet, although no effect was seen on body weight gain.
The results show that mechanical degradation mainly takes place in the so-called "cooking" zone where the amylopectin chains break and the size of their molecules reduces (10).
Starch type may influence performance also, however, FCR was significantly better between days 19-42 when birds were fed a normal variant compared to a waxy (high amylopectin) variant although birds fed the waxy maize were significantly heavier (Collins et al., 2003).
Food: Structure and Dynamics: Assessment of Meat Quality by NMR; [sup.1]H NMR Relaxation Study of Amylopectin Retrogradation; [sup.23]Na and [sup.35]CI NMR Studies of the Interactions of Sodium and Chloride Ions with Meat Products; NMR Studies of Complex Foods in Off-line and Online Situations; Determination of Water Self-Diffusion Behaviour in Microorganisms by using PFG-NMR.
The Archer Daniels Midland Company of Decatur, Illinois, uses the product of a mutant from this center for producing its pure amylopectin, a branched starch that is an important ingredient in human foods.
Common starch contains two types of molecules, a linear molecule of amylose, and a highly branched molecule of amylopectin. Because of its linear structure, amylose has good film-forming properties.
The starch granule consists of amylose and amylopectin composed of [alpha]-D-glucopyranosyl units [([C.sub.6][H.sub.10][O.sub.5]).sub.x] Amylose has a linear conformation and an average molecular mass of 105 g while amylopectin is a branched structure having an average molecular mass of around [10.sup.6]-[10.sup.7] g [mo1.sup.-1].
The starch present in barley is a polysaccharide which consists of the polymers amylase and amylopectin. It has a high metabolizable energy content which is provided by a large proportion of rapidly fermentable starch located within the endosperm of the grain kernel.
Measurement of the chain length of amylopectin and its relevance to the origin of crystalline polymorphism of starch granules.
Along with gums, starches are among the most frequently used agents to promote thickening, which typically occurs when the starch granule--often an aggregate of linear amylose and branched amylopectin molecules--is heated in water, causing weaker hydrogen bonds to rupture and the granule to swell with progressive hydration.
Wheat starch is composed of molecules known as amylose and amylopectin. Wheat flour low in amylose, for example, is desirable for noodlemaking because it improves noodle texture.