Effect of acid‐ethanol treatment on physicochemical properties and in vitro digestibility of maize starches varying in AM content

In the current work, three maize starches with different AM/AP content were treated with hydrochloric acid in ethanol solvent to prepare modified starches and to study the effect of acid‐ethanol treatment on starches. Results showed that with increase of treatment time, the hydrolysis rate of maize starches increased. Native WMS had the highest hydrolysis rate. After treatment, starch granules exhibited decreased birefringent and morphology was destroyed. The modified Hylon V retained its granular appearance with only some slight breakage. Solubility of acid‐ethanol treatment starches profoundly increased with increasing measurement temperature and decreased with increasing AM content. Crystalline type of modified starches was not changed and the relative crystallinity increased. The gelatinization temperatures after acid‐ethanol treatment increased except Tₒ, while ΔH decreased. The average rate of digestion for each acid‐ethanol treated starch was higher than that of its counterpart native starch. With increasing AM content, the digestion rates of native and modified starches decreased.