Amylopectin (without amylose) can be isolated from 'waxy' maize starch whereas amylose (without amylopectin) is best isolated after specifically hydrolyzing the amylopectin with pullulanase . Genetic modification of starch crops has recently led to the development of starches with improved and targeted functionality.
➢ two types of molecules of STARCH , amylose (normally 20-30%) and amylopectin (normally 70-80%). Both consist of polymers of α-D-glucose units in the 4C1 conformation. In amylose these are linked -(1[pic]4)-, with the ring oxygen atoms all on the same side, whereas in amylopectin about one residue in every twenty or so is also linked -(1[pic]6)- forming branch-points. The relative proportions of amylose to amylopectin and -(1[pic]6)- branch-points both depend on the source of the starch, for example, amylomaizes contain over 50% amylose whereas 'waxy' maize has almost none (~3%)
Amylose, Amylopectin (starch)
[pic] Amylose and amylopectin are different forms of starch.
Plant starch comes in two different forms: amylose (20-30%) and amylopectin (70-80%), each with their own physical and chemical properties:
• Amylopectin consists of large, highly-branched molecules, making up the majority of the starch found in plants.
• Amylose consists of long, chain-like molecules.
Properties of amylopectin such as water solubility and bonding capacity make it more useful for technical applications in the food, paper, and chemical industries. It is well suited for use in pastes, adhesives, and lubricants. The food industry also takes advantage of its properties.
Usually, amylose and amylopectin must be separated or modified by chemical, physical, or enyzmatic means.
For several years, researches have been working on potatoes genetically modified to contain exclusively amylopectin starch. Scientists discovered a gene (GBSS, granular binding starch synthase) that encodes an enzyme...