Effect of Heat-moisture Treatment on the Physicochemical Properties and Digestibility of Starches with Different Crystal Structures

In this study, three types of starch, each with a different crystal structure [corn starch(A-type), potato starch(B-type) and pea starch(C-type)] were treated usingheat at 120 ℃ for 13h in the presence of 25% moisture content. The effect ofheat-moisture treatment was studied in terms of physicochemical properties and digestibility of starch. The results showed that, compared with native starch, the crystal structures of all three starches changed afterheat-moisture treatment. The original A-type structure of corn starch changed to(A+V)-type, while both, B- and C-type structures present in potato and pea starches changed to A-type. The starch granules showed different degrees of damage on the surface, while some showed a decrease in the central intensity of the Maltese cross. The temperature required for gelatinization increased and the enthalpy values decreased in A- and B-type starches but increased in C-type. The content of resistant starch component was elevated and the anti-peptic activity was significantly enhanced. The changes in C-type starch were observed as most significant.