Effect of protein from endosperm on the structure and gelatinization behavior of corn starch under radio frequency treatment

Thermal treatments affect the interactions between protein and starch that play an important role in the structure and properties of starch–based foods. This study investigated the effects of protein from endosperm on the structure and gelatinization behavior of corn starch under hot air (HA) assisted radio frequency (RF) treatment. As the temperature increased to 70 °C, the amylose content in dent and flint corn starch increased from 10.76% to 20.65% and 10.80% to 22.43%, respectively. Protein from endosperm increased the crystallinity, short–range ordered structure, and gelatinization temperatures, while inhibited the swelling and reduced the water solubility of starch. Meanwhile, protein hindered the formation of a dense network gel structure, which decreased the rheological properties and apparent viscosity of starch gels. The finding will enrich the theory knowledge of effects of HA-RF treatment on the starch–protein interaction, and have important implications for the development of carbohydrate–restricted diets and desirable function foods. [Display omitted] •Protein increased crystallinity and short–range order of HA-RF treated starch.•Gelatinization temperature of starch increased under HA-RF treatment with protein.•Protein inhibited swelling and reduced solubility of starch after HA-RF heating.•Starch–protein interaction led to the formation of a weaken starch gel structure.