https://doi.org/10.1016/j.nfs.2025.100240
Abstract
In this article, two analytical topics and one nutritional topic are covered. 1. Analytical: the effects of formic acid and trifluoroacetic acid (TFA) at different concentrations in size exclusion chromatography (SEC) for peptide analysis were evaluated. 2. Analytical: three methods for the analysis of peptides after in vitro digestion according to the INFOGEST protocol were compared: photometric quantification after OPA derivatization, SDS–PAGE and SEC. 3. Nutritional: using the most suitable and optimized analytical method, the digestibility of nine protein concentrates from plants and two animal proteins was evaluated.
The results are as follows: 1. Alternative additives or low TFA concentrations compromise peak resolution. 2. When the digestibility of proteins is evaluated, it is necessary to determine the small peptides that are bioaccessible. This was possible only by SEC. 3. The digestibility of plant proteins – as determined by SEC after in vitro digestion – was found to be in the same range or higher than that of animal proteins.