Annealing of normal, low and high amylose starches extracted from barley cultivars grown under different environmental conditions

Annealing studies were conducted on waxy, normal and high amylose barley starches extracted from cultivars grown at different temperatures. Starches grown at relatively low temperatures comprised a greater proportion of crystalline defects and were hence less ‘perfect’ than starches grown at the higher temperatures. Annealing of the starches caused very significant increases in gelatinisation temperatures, a small increase in the gelatinisation enthalpies and little change with respect to crystal size. It is proposed that the annealing process diminishes amylopectin crystalline defects by improving double helix registration and optimising the length of the double helices within crystallites.