Physicochemical and digestion characteristics of flour and starch from eight Canadian red and green lentils

Zhan-Hui Lu, Elizabeth Donner, Rong Tsao, D. Dan Ramdath, Qiang Liu

Index: 10.1111/ijfs.13649

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Abstract

Summary Physicochemical and nutritional properties of flour and isolated starch from eight Canadian lentil cultivars were assessed to identify unique samples and key factors affecting starch digestion. The results showed that nearly half of apparent amylose in lentil flours was underestimated because it was complexed and embedded within the flour matrix, which led to slower starch digestion of cooked flour. Cooked red lentil flours showed significantly higher resistant starch content (11.0%) than flours from green lentils (6.8%) (P < 0.05). Among green lentils, Asterix and Greenland were unique for their high slowly digestible starch content after cooking, possibly owing to their high phenolic content and α-glucosidase inhibitory activity. Long- and short-range ordering in starch was more indicative of low starch digestion for raw or cooked lentil flour rather than for isolated starch. The results suggest the flour matrix protects the starch ordered structure from enzyme hydrolysis. Biplot of the principal components 1 and 2, describing the scores and variation in physicochemical and nutritional properties of raw and cooked lentil flours and starches. Abbreviations: AA, apparent amylose content; RC, relative crystallinity; SDS and RS, slowly digestible and resistant starch, respectively; Suffix “f” and “s” indicate lentil flour and isolated starch, respectively.