Behaviors of large A-type and small B-type wheat starch granules esterified by conventional and pulsed electric fields assisted methods

Large and small wheat starch granules were modified by conventional and pulsed electric fields (PEF)-assisted dual esterification methods. Due to the assistance of PEF, the degree of substitution (DS) of AS and BS increased by 0.0159 and 0.0066, respectively, while the crystallinity of them decreased by 1.7% and 1.2%. An increase in diffraction intensity at q = 0.68 nm^-1 was observed in dual modified starch compared to conventional method. The DS of A-type starch (AS) were more sensitive than B-type starch (BS) and the thermal stability of AS was decreased obviously than that of BS. It was found that esterified starch exhibited superior freeze-thaw stability than native starch, especially for the PEF-assisted esterification of AS rather than BS. The resistant starch of esterified BS was increased while the slowly digestible starch was decreased, especially for the assistance of PEF.