Microstructure, thermal properties and susceptibility of the high amylose wheat starch to enzymatic hydrolysis: a new material for resistant starch (RSIII) production.

Differential scanning calorimetry, optical (LM) and scanning electron (SEM) microscopy methods were used for studying the properties and structure of type III resistant starches obtained from high amylose (39.5% amylose) wheat starch. The susceptibility of RSIII starch to enzymatic hydrolysis was also studied. This study has shown that the structure of the investigated, laboratory-obtained preparation was highly influenced by the processing parameters - indicating changes typical of a repeated heating-cooling process. Thermal properties connected with the presence of amylose-lipid complexes, as well as ordered structure fragments in the preparations, were in high accordance to those reported in literature for RSIII preparations from normal wheat, high amylose barley and pea starches as well as commercial types - Novelose 303 or CrystaLean. It was shown that high amylose wheat is a promising raw material for processing bakery and extrusion food products with a reasonably high content of resistant starches without the addition of commercial resistant starches to meal or extrusion mixture.