Impact of amylose from maize starch on the microstructure, rheology and lipolysis of W/O emulsions during simulated semi‐dynamic gastrointestinal digestion

Summary This study aims to examine the microstructure, rheology and lipolysis of water‐in‐oil (W/O) emulsions (40 wt.%) prepared with or without (Control) the addition of normal (NAM) and high amylose (HAM) maize starch during simulated digestion in a semi‐dynamic gastrointestinal tract (GIT) model. Microstructural examinations showed modification in initial W/O emulsion droplets to multiple W 1 /O/W 2 droplets during in vitro digestion. This is in line with the rheological results, where the shear viscosity and moduli in the oral phase were remarkably reduced after entering the intestinal phase. In comparison to control and NAM emulsions, HAM emulsions showed a more compact and continuous network structure and greater viscosity and elastic modulus throughout GIT digestion. These results support lipolysis, where fewer free fatty acids were released in the HAM emulsion (70%) than in the control (86%) and NAM (78%) emulsions. This work has provided an in‐depth understanding of the digestion of W/O emulsions as influenced by amylose content, which is meaningful for the development of low‐fat products with reduced lipid digestibility.