Effect of pulsed electric fields assisted acetylation on morphological, structural and functional characteristics of potato starch

•A brand-new dual modification method for starch acetylation is proposed.•The highest DS value (0.13) is optimized upon RSM with shorter reaction time.•PEF-assisted acetates show superior retrogradation, freeze–thaw stability, BD and SB.•PEF can promote molecular motion, alter external appearance and internal structure. Pulsed electric fields (PEF)-assisted acetylation of potato starch with different degree of substitution (DS) was prepared and effects of PEF strength, reaction time, starch concentration on DS were studied by response surface methodology. Results showed DS was increased from 0.054 (reaction time of 15min) to 0.130 (reaction time of 60min) as PEF strength increased from 3 to 5kV/cm. External morphology revealed that acetylated starch with higher DS was aggravated more bulges and asperities. Fourier-transformed infrared spectroscopy confirmed the introduction of acetyl group through a band at 1730cm−1. The optimum sample (DS=0.13) had lower retrogradation (39.1%), breakdown (155 BU) and setback value (149BU), while pasting temperature (62.2°C) was slightly higher than non-PEF-assisted samples. These results demonstrated PEF treatment can be a potential and beneficial method for acetylation and achieve higher DS with shorter reaction time.