A Rapid <b><i>In‐vitro</i></b> Digestibility Assay Based on Glucometry for Investigating Kinetics of Starch Digestion

Abstract

Abstract The potential of glucometry in in‐vitro starch digestion was investigated for developing a rapid procedure to understand kinetics of digestion. A hand‐held glucometer, intended for testing of plasma glucose levels, was used for the assay of glucose released by the combined action of α‐amylase and amyloglucosidase on a range of starch substrates. The glucometer was sensitive to glucose concentrations in water, and its readings were independent of pH (7.7 and 3.9) and temperature (37°C and 25°C) of the glucose solution, but dependent on lactose and maltose concentrations. Neither fructose nor sucrose affected the readings. Digested starch calculated from the glucometer was not significantly ( p &gt; 0.05) different from that calculated from spectrophotometry. Particle size of substrate, sample formulation, grain genotype, and processing affected the glucometer readings as expected from how these factors influence starch digestibility. Corrections are required when samples containing lactose and maltose prior to in‐vitro digestion analysis are studied. The developed rapid procedure can be used to collect large numbers of data points per sample per analysis for better understanding the kinetics of starch digestion, and increased confidence level in modelling the digestogram. The glucose detection method is robust and could be adapted for non‐laboratory use. Single‐point data can also be extracted from digestograms for comparative analysis.