Effects Of Different Pre-treatments On The Preparation And Properties Of Starch Octenylsuccinate

Due to the low synthesis efficiency of octenyl succinic anhydride(OSA)modified starch in aqueous phase system.The study aimed to improve the reaction efficiency of starch modification with OSA and the degree of substitution(DS)of the derivative by pre-treatments of starch.This experiment studied the effects of freezing-thawing(F/T)and hydrothermal-alkali(HA)pre-treatments on the modification of corn and potato starch with OSA,and the effects of CaCl2 solution pre-treatment on the modification of potato starch with OSA.The degree of substitution and reaction efficiency of modified starches were determined and calculated.What's more,the granule morphology,Fourier Transform Infrared spectroscopy and LCM-Raman spectroscopy,X-ray diffraction pattern,thermal properties,pasting properties,calcium content,swelling power and solubility,paste transparency,texture properties,emulsifying ability and emulsion stability was measured and analyzed.Hydrothermal-alkali pre-treatment can improve the reaction efficiency of the OSA modification of corn and potato starch and the DS of the derivative.Hydrothermal-alkali freeze-drying(HAF)treatment has the best effect.Freezing-thawing pre-treatment reduced the efficiency and DS of OSA modified corn starch,but had no significant effect on the OSA modification of potato starch.Freezing-thawing and hydrothermal-alkali ethanol drying(HAED)treatment significantly changed the granule morphology of corn starch,but had little effect on potato starch.While the HAF treatment caused great damage to the potato starch granules.Both pre-treatments and OSA modification reduced the short-range order of corn starch,and HAF treatment significantly reduced the short-and long-range order of potato starch.OSA modification reduced the gelatinization temperatures and enthalpy of both starches,but the effects on paste viscosities were inconsistent.OSA modification greatly improves the emulsifying ability and emulsion stability of native starch.Pre-treatment with 1 M CaCl2 solution improved the reaction efficiency of subsequent OSA modification and the DS of the derivative,while 0.05-0.5 M CaCl2b solution pre-treatment had no obvious effects on the subsequent OSA modification.The 1M CaCl2 solution caused damage on the starch granules with a decrease in relative crystallinity and gelatinization enthalpy.CaCl2 solution pre-treatment and OSA modification significantly reduced the peak viscosity and breakdown value of native potato starch but increased the setback value.Pre-treatment with CaCl2 solution reduced the swelling power and paste clarity of native starch.OSA modification improves the transparency of native starch pastes.Pre-treatment with CaCl2 did not significantly alter the emulsifying ability and emulsion stability of native starch,while OSA modification significantly increased both.OSA modification significantly reduced the textural properties of native starch,but OSA modified pre-treated starches had higher hardness,stickiness and chewiness than untreated OSA starches.