Effects of sodium hypochlorite on the physicochemical characteristics of arrowhead starch

Objective: The effect of sodium hypochlorite on the physicochemical properties and digestive characteristics of arrowhead starch was studied. Methods: In a weakly alkaline environment, sodium hypochlorite was used as an oxidant, and the added amounts were 0%, 1%, 3%, 5%, 7%, and 9% (based on the mass fraction of available chlorine in dry basis arrowhead starch). Following a 4-hour oxidation reaction with arrowhead starch, the modified starch's amylose content, swelling power, solubility, coagulation stability, color difference, light transmittance, scanning electron microscopy, X-ray diffraction, and other physical and chemical properties were measured, along with its digestibility. Results: The amylose concentration, solubility and transparency all arose as the additive amount was increased. The amylose content increased from 55.59% to 79.02%. When the addition amount was 5%, 7%, and 9%, the light transmittance reached more than 90%. When the addition amount was 9%, the light transmittance reached 97.13%. At 80 ℃, with the increase of the addition amount, the solubility increased from 4.01% to 32.59%, while the swelling power decreased, and the crystallinity of starch decreased from 43.99% to about 25.00%, The surface of starch became rough gradually, the crystal structure of starch was destroyed, and the content of amylose increased. Conclusion: Sodium hypochlorite could significantly change the properties of arrowhead starch, and the changes in properties vary with the amount of addition.