In vitro assessment of the starch digestibility of western Canadian wheat market classes and cultivars

The objective of the study was to measure the effect of wheat market class and cultivar on starch digestibility using an in vitro model that mimics chicken digestive tract and relate it to grain characteristics. The study evaluated 18 wheat cultivars from eight western Canadian wheat classes and, each cultivar was replicated four times. Samples were subjected to gastric and small intestine (SI) digestion phases and each sample was assayed in triplicate; glucose release was measured in SI phase. Starch granule distribution, amylose, total starch, crude protein (CP), ash, and non-starch polysaccharides (NSP) were analyzed in all wheat samples. Small intestinal phase times of 15, 60 and 120 min were chosen to approximate digestion in the terminal duodenum, jejunum and ileum. Starch digestibility of wheat classes ranged as follows: 15 min â 33.1 to 49.1%, 60 min â 80.2 to 93.3% and 120 min â 92.4 to 97.6%. Starch digestibility positively correlated with CP, ash, NSP and % large granules whereas, it negatively correlated with total starch, and proportion of small and medium granules. In conclusion, market class and cultivar of western Canadian wheat affects both rate and extent of starch digestibility and it is related to various grain characteristics.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author