Starch digestibility in food matrix: a review
In this review, recent reports on in vitro starch hydrolysis kinetics are reviewed with regard to the structural characteristics of starches. Factors such as starch granule morphology, amylose to amylopectin ratio, molecular structure, degree of branching in terms of steric hindrance and consequently mass transfer resistance and their effects on the digestibility and absorption of digested carbohydrates have been examined. The physical state of the starch ingested has a major impact on the digestibility therefore effects of processing techniques (thermal processing, extrusion cooking, autoclaving etc. and starch modification have been discussed. The other constituents of the food matrix, such as proteins, lipids and polysaccharides, play a significant role during processing which affects the physico chemical characteristics of digesta and the final digestibility of starch. Some molecules naturally occurring in food sources may confer an inhibitory effect during starch hydrolysis.