Functionality of porous starch obtained by amylase or amyloglucosidase treatments

Porous starch is attracting very much attention for its absorption and shielding ability in many food applications. The effect of two different enzymes, fungal alpha-amylase (AM) or amyloglucosidase (AMG), on corn starch at sub-gelatinization temperature was studied as an alternative to obtain porous starch. Biochemical features, thermal and structural analyses of treated starches were studied. Microscopic analysis of the granules confirmed the enzymatic modification of the starches obtaining porous structures with more agglomerates in the case of AMG treated starches. Several changes in thermal properties and hydrolysis kinetics were observed in enzymatically modified starches. Hydration properties were significantly affected by enzymatic modification being greater influenced by AMG activity, and the opposite trend was observed in the pasting properties. Overall, results showed that enzymatic modification at subgelatinization temperatures really offer an attractive alternative for obtaining porous starch granules to be used in a variety of foods applications. (C) 2013 Elsevier Ltd. All rights reserved.