Dynamic measurement of starch granule swelling during microwave heating

•Swelling behavior of various corn starches during microwave heating was studied.•Granule size distribution in dilute suspension was measured with laser scattering.•Data from this and conventional heating (from a previous study) were compared.•No differences in swelling behavior between heating treatments were observed. The size of starch granules in dilute aqueous suspension was measured in-line during gelatinization in a microwave-heated, well-mixed system. The results were compared with those of a previous study conducted with conventional heating. For the starches used (common corn, waxy maize, and cross-linked waxy maize), no significant difference was found between microwave and conventional heating in terms of maximum diameter, temperature of maximum rate of diameter increase, or diameter vs. temperature behavior. These results suggest that there are no differences in the swelling behavior of common and modified maize starches between microwave and conventional heating.