Exploring Variations in Protein Composition in Pea Seeds and Processed Ingredients: A Comparative Analysis of Five Pea Varieties Using Targeted Parallel Reaction Monitoring Mass Spectrometry (PRM‐MS)

ABSTRACT Pea seeds are a good source of sustainable plant‐based proteins. Increasing their utilization will depend on gaining a precise quantitative understanding of important quality‐determining proteins from the seed matrix and tracing their changes through processing. Selected major and minor seed storage proteins (vicilins, legumins, albumins, lipoxygenases (LOX), and nonspecific lipid transfer proteins (nsLTP)) were quantified from five pea varieties (CDC Lewochko, CDC Meadow, CDC Spectrum, CDC Amarillo, and AAC Profit) using a targeted parallel reaction monitoring (PRM) mass spectrometry (MS) method. Protein content in pea flour ranged from 22.9% in CDC Meadow to 29.0% in CDC Spectrum. Most pea flours had a higher abundance of vicilins followed by legumins, LOX, albumins, and nsLTP, while CDC Spectrum had a higher abundance of legumins than vicilins. CDC Spectrum had the lowest amounts of all three classified allergens, while CDC Meadow and AAC Profit had the highest quantities. Protein concentrate and isolate prepared from the high‐protein variety CDC Spectrum contained 63.9% and 88.3% protein, respectively. Protein isolate from CDC Spectrum had a relatively higher abundance of vicilins and a lower abundance of LOX, albumins, and nsLTP, compared to flour and concentrate, lowering its sulfur‐containing amino acid content. This approach of simultaneous quantitation of high‐ and low‐abundance seed proteins can support future crop development and postharvest process design workflows to select for and develop customized protein ingredients for tailored food applications.