Optimization and Analysis of Corn Resistant Starch Prepared by Cross-linking Method and Its Physical and Chemical Properties

In this paper, corn starch was used as raw material to prepare resistant starch by cross-linking method. The preparation process parameters of corn resistant starch were optimized through single factor experiment and center combination. The physicochemical properties of the prepared crosslinked starch were compared with esterified starch and original starch. It compared the properties of transparency, solubility, degree of swelling and freeze-thaw stability. The optimal modification reaction conditions obtained by the cross-linking method were as follows: The reaction time was 3.5 h, the cross-linking agent concentration was 11.5%, the substrate concentration was 0.71 g/mL, and the reaction temperature was 60 ℃. The model and the experiment fitted well. The prepared resistant starch content was 60.76%. It was confirmed by infrared spectroscopy that the cross-linking reaction occurred, the solubility of the cross-linked resistant starch increased, and the swelling degree and freeze-thaw stability decreased. Finally, observed by scanning electron microscope, this study found that the shape and size of starch granules are not significantly different from original starch. The study provides a reference for the industrial production of corn resistant starch.