Adult and elderly in vitro digestibility patterns of proteins and carbohydrates as affected by different commercial bread types

From static to semi-dynamic in vitro digestion conditions relevant for the older population: starch and protein digestion of cooked lentils

“…These results are in line with final levels of proteolysis reported for digestion of bread, and wheat and pea protein under healthy versus older adult conditions (gastric pH 4.5). 27,29 In contrast, other studies observed a decreased small intestinal protein digestibility using an elderly model similar to the one employed here for different meat 14 and fish 13 samples, quantifying released amino acids using a GC-MS system. Possibly, a readily bioaccessible peptide fraction with different molecular weight or DP distribution could be formed as a result of digestion under healthy versus older adult conditions.…”

“…In literature, proceeding degradation of starch (initiated during the oral phase upon addition of salivary amylase) has been described to gradually render proteins more accessible to proteolytic enzymes, resulting in a higher overall protein digestibility. 29,55,56 Additionally, the formation of readily bioaccessible protein could potentially be increased to some extent by the addition of saliva through precipitation of certain protein fractions (food protein aggregation and precipitation by salivary mucins have been reported through different interaction modes 57 ), improving the accessibility of more soluble peptides to proteolytic enzymes.…”

“…In accordance with the current study, a more rapid amylolysis was observed in white bread applying an older adult model (including salivary amylase) compared to a healthy adult model, however reaching similar final starch hydrolysis extents. 29…”

“…1 and Table 2), a higher amount of BAC was also observed in static healthy adult simulations incorporating saliva compared to those without saliva. This was previously explained by possible effects such as the increased accessibility of proteins to proteases upon gradual (orogastric) amylolysis 29,55,56 and the potential precipitation of food proteins in presence of salivary proteins ( e.g. , mucins) ultimately facilitating proteolysis of more soluble proteins/peptides.…”

“…Doing this, it could be evaluated to which level typical attenuated hydrolysis patterns of intact cotyledon cells (such as slow starch digestion), observed using healthy adult in vitro models, were affected by gastrointestinal conditions observed in older adults. White bread was selected as a reference food system since it is a well-studied source of both (rapidly digestible) starch and protein, 27–29 and it is much-consumed by the targeted population group. The comparison of lentil digestion kinetics to those of white bread could deliver insight into the (possibly different) consequences of applying altered digestion conditions for two differently structured foods.…”