Thermal Stability and in Vitro Digestive Behavior of Pickering Emulsion Stabilized by High-Amylose Starch Nanocrystal

Abstract

High-amylose starch nanocrystals (HASNC) were produced from high-amylose starch (HAS) using sulfuric acid and ultrasound. HASNC and its emulsions inherited characteristics of HAS, including high resistance to heat and digestive enzymes, while normal starch nanocrystals (NSNC) and their emulsion were set as controls. Specifically, (1) upon 100°C heat treatment and in vitro stomach and mouth tests, HASNC-stabilized emulsion was much more stable and had a significantly higher β-carotene retention than NSNC-stabilized emulsion due to the lower level of gelatinization of HASNC and its stronger steric stabilization for oil droplets. (2) In vitro small intestine tests, HASNC-stabilized emulsion led to delayed access of lipase and bile salts to oil droplets. Thus, the HASNC-stabilized emulsion was found to be suitable for further applications such as developing functional foods to control satiety or designing delivery systems for the sustained release of bioactive compounds.

Keywords: high-amylose nanocrystal, Pickering emulsion, heat resistance, bioavailability, sulfuric acid-ultrasound cross-linking