Wheat Porous Starch：Preparation and Characteristics with Dextranase-Catalyzed Rotation

The preparation of porous starch by biological enzyme method is mild conditions, simple process, and environmentally sustainable. This study employed a dextranase with specific hydrolysis of α-1,6-glycosidic bonds ability to prepare porous wheat starch. The structure of the starch was analyzed by X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, and particle size analysis. The rates of starch swelling, oil and water absorption, and drug loading, as well as solubility, were measured. The results showed the formation of pores on the starch surface after treatment at 50 ℃ for 16 h, together with reduced particle sizes, while the crystal structure of the starch did not change significantly. The specific volume of the porous starch was 2.11±0.02 cm³/g, and the solubility was 9.02%±0.21%. Swelling reached 9.91%±0.22% while the water and oil absorption rates were increased to 80.12% and 78.23%, respectively. The loading rates of curcumin, dabigatran mesylate, nystatin, and ofloxacin in a 160:1 ratio reached an average of 75.07%. In vitro experiments showed that the release rate of curcumin loaded onto wheat porous starch was significantly reduced. The release rate in stomach for 2.5 h was approximately 30%, and it was approximately 40% in intestine for 5 h. The research results provided a basis for the preparation and application of wheat porous starch.