Using Native Mass Spectrometry to Analyse Proteins Directly from Food

Globally, food is a multi-trillion-pound industry for which proteomic analysis represents a key tool in ensuring that consumer health and rights are maintained. Here we use native mass spectrometry methodology to analyse a series of natural food products of varying complexity, namely: cow milk (liquid); chicken egg white (viscous liquid) and jack bean meal (solid). Our approach permits rapid detection (~5-30 mins) and unambiguous identification of the majority (>80%) of proteins present within milk and egg white, which are foodstuffs that between them comprise two of the most prominent sources of allergenic proteins within the food industry. Furthermore, we show that this method also enables the retention of bioactive protein complexes directly from natural sources, exemplified by the detection of three multimeric states (monomer, dimer and tetramer) of concanavalin A, naturally found in jack beans (Canavalia ensiformis). As such, we propose that native mass spectrometry methods can augment the current bottom up proteomic toolkit employed within food analyses and may prove useful for fast detection and high accuracy identification of suspected proteinaceous allergens/adulterants within sufficiently noncomplex food substances.