To increase our insights in the nutritional and functional benefit of meat proteins, knowledge on its digestion after consumption are crucial. Information about protein truncation during digestion is critical to track the relative abundance of the released peptides during both gastric as well as intestinal digestion stages. Apart from the protein breakdown, digestion may also release peptides that display functionality in addition to their nutritional value, such as bioactivity. Bioactive peptides are known to display a variety of health-promoting activities including anti-hypertensive, anti-oxidant and anti-inflammatory properties. The digestion process may release these bioactive peptides which are encrypted in larger protein sequences. However, passage through the gastrointestinal tract drastically alters peptide profiles and thus may enhance of limit the amount of bioactive sequences found.
In this study, we compared the peptide compositions after simulated gastrointestinal digestion of powdered meat samples from 18 month old steers and of enzymatically produced meat hydrolysates. These meat protein hydrolysates are important in the food industry due to their versatility of use, from flavour enhancers to functional ingredients. To evaluate the differences in in vitro digestion between meat powder vs meat hydrolysate, we performed a label-free quantitative proteomic analysis. Data were acquired via data-dependent acquisition on an Impact HD Q-TOF. Protein and peptide identification was performed using Peaks Studio software. Further data analysis via principal component analysis displayed a clear distinction in the number and the type of peptides produced in meat powder vs. hydrolysed meat. Additional bioactivity profiling using our in-house database showed that numerous bioactives were generated during simulated digestion of the meat hydrolysate, while fewer hits were found in the meat powder. This indicates the potential of meat hydrolysates as functional ingredients in foods.