Mass spectrometry for nutritional peptidomics: How to analyze food bioactives and their health effects.

We describe nutritional peptidomics for discovery and validation of bioactive food peptide and their health effects. Understanding nature and bioactivity of nutritional peptides means comprehending an important level of environmental regulation of the human genome, because diet is the environmental factor with the most profound life-long influence on health. We approach the theme from three angles, namely the analysis, the discovery and the biology perspective. Food peptides derive from parent food proteins via in vitro hydrolysis (processing) or in vivo digestion by various unspecific and specific proteases, as opposed to the tryptic peptides typically generated in biomarker proteomics. A food bioactive peptide may be rare or unique in terms of sequence and modification, and many food genomes are less well annotated than e.g. the human genome. Bioactive peptides can be discovered either empirically or by prediction: we explain both the classical hydrolysis strategy and the bioinformatics-driven reversed genome engineering. In order to exert bioactivity, food peptides must be either ingested and then reach the intestine in their intact form or be liberated in situ from their parent proteins to act locally, that is in the gut, or even systemically, i.e. through the blood stream. This article is part of a Special Section entitled: Understanding genome regulation and genetic diversity by mass spectrometry.