A comparison of the structures of the fractions of normal and high-amylose pea-seed starches prepared by precipitation with concanavalin A

✍ Scribed by Norman K. Matheson

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 682 KB
• Volume: 199
• Category: Article
• ISSN: 0008-6215
• DOI: 10.1016/0008-6215(90)84261-r

✦ Synopsis

A method of separating amylose and amylopectin is based on proteolysis of the precipitated concanavalin A-amylopectin complex. The molecular-size distributions, together with the i,,, and A,,, of the iodine complexes of fractions obtained by gel chromatography, indicated efficient separation ofamylose and amylopectin. The amylose from the normal (n) genotype of pea seeds had a M, higher than that from the high-amylose (HA) genotype. Hydrolysis by the debranching enzyme indicated a slight degree of branching in each amylose and that the branches associated with HA-amylose were shorter. The m,, of HAamylopectin was lower and the column fractions gave a stronger colour with iodine and higher I,,, than for the n-amylopectin. The total average chain-length and internal and external average chain-lengths were all higher for the HA-amylopectin.

There was no evidence of a significant quantity of an intermediate fraction.