Effects of radio frequency explosion puffing on the texture of purple sweet potato chips and the physicochemical properties of the flour under different energy inputs and pressures

This study elucidated the mechanism through which radio frequency explosion puffing (RFEP) improved the texture of purple sweet potato chips by inducing multiscale structural changes. Higher energy inputs and pressures resulted in higher crispness, porosity, acceptability, and lower bulk density. RFEP disrupted hydrogen bonding, hydrophobic interactions, and ionic bonding within the flour, resulting in partial separation of starch and protein. This process decreased the short-range ordering and the LF–β–sheet and β–turn contents, despite the primary structure of proteins remaining intact. These changes led to a looser flour structure and a decrease in storage modulus. Notably, storage modulus, short–range ordering, LF–β–sheet, and β–turn parameters were significantly negatively correlated with crispness and porosity and positively correlated with bulk density. Taking the processing costs into account, the optimum puffing conditions were determined as a pressure of 0.2 MPa, a puffing temperature of 90 ^οC and a holding time of 0 min.