In vitro gastrointestinal digestion of glabrous canaryseed proteins as affected by variety and thermal treatment.

Glabrous or hairless canaryseed is a nutritional grain that could be a good addition to the diet if approved as a novel food. To assess the impact of thermal treatment on its digestibility; raw, roasted or boiled flours prepared from three different varieties of glabrous canaryseed were subjected to in vitro gastrointestinal digestion conditions and the effect on protein electrophoretic profiles was examined using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Roasting was done by dry-heat in an oven at 176 °C for 12 min whereas boiling was done in water at 98 °C for 12 min. SDS-PAGE showed approximately twenty-five protein bands in the undigested raw flour with molecular masses (MM) ranging from <14 kDa to >97 kDa. The dominant proteins had low MM, between the ranges of ~57 to 12 kDa. Roasting markedly altered the protein electrophoretic profile with the appearance of large molecular weight aggregates. Canaryseed proteins were more easily digested after thermal treatment and under sequential gastric-duodenal conditions than under gastric or duodenal conditions alone. Furthermore, roasting appeared to have a greater impact on in vitro protein digestibility than boiling.