Effects of pectin-calcium matrices on controlling in vitro digestion of normal maize starch

Normal maize starch was encapsulated with different (low-methoxyl) pectin concentrations (2–7%, w/v) using the ionic gelation method. The mixtures were ejected into the crosslinking agent (5%, w/v calcium chloride solution) by an electrospinning apparatus. In order to study the effects of pectin-calcium matrices on starch digestion, the particle size distribution, thermal properties, and in vitro starch digestion kinetics of the encapsulated sample were consequently studied. The results showed that the encapsulation successfully diminished starch amylolysis, indicated by the reduction of digested starch and the apparent digestion rate coefficient. The highest pectin concentration (7%, w/v) caused the greater network formation, which contributed to the greatest particle size distribution and highest gelatinization temperature but caused the lowest starch hydrolysis (p < 0.05). This study found that pectin-calcium matrix development is a crucial key in controlling starch hydrolysis since the network provides a complex structure and reduces the surface areas of starch granules that are available to the digestive enzyme.