Self-assembling bioactive peptides for gastrointestinal delivery-Bioinformatics-driven discovery and in vitro assessment

Food-derived peptides are promising materials for oral delivery purposes as they are readily available, can be generated using common techniques, and their self-assembly properties can be tuned for specific applications. A method for identifying such self-assembling bioactive peptides (SABP) candidates based on in silico analysis was developed and allowed for the discovery of a bovine-derived SABP: FFVAPFPEVFGK. This peptide was then successfully generated from the alpha s1-casein using enzymatic hydrolysis and isolated with size exclusion chromatography. Furthermore, we assessed the in vitro potential of the peptide for oral delivery to the lower gastrointestinal tract, using the INFOGEST standardised protocol. Transmission electron microscopy and mass spectrometry analyses showed that both the natural and the synthetic peptide were able to resist degradation in the oral and gastric phases. Indeed, the peptides remained assembled at the end of the gastric phase with some of the structure eroded from the action of pepsin and/or the pH. This article provides further insight into the potential of food-derived peptides as functional food ingredients for oral delivery.