Monitoring the Aroma Profile During the Production of a Pea Protein Isolate by Alkaline Solubilization Coupled with Isoelectric Precipitation

The aroma profile was monitored during an optimized pH-extraction method (alkaline solubilization coupled with isoelectric precipitation) to produce pea protein isolates (PPIs). Samples were taken at different steps throughout the protein extraction. The aroma compounds were isolated from these samples using solvent-assistant flavor evaporation (SAFE) and were identified by gas chromatography-mass spectrometry-olfactometry (GC-MS-O) and gas chromatography-time-of-flight-mass spectrometry (GC-TOF-MS). A sensory evaluation of pea flour (PF) and PPI aqueous solutions was also conducted. From the instrumental analysis, 13 compounds were found to be likely the main contributors to the aroma profile of the samples examined. This hypothesis was also supported by the sensory data, which showed that the PF and PPI aqueous solutions were described with some of the odor descriptors used during the instrumental analysis. No new aroma compounds appear to be produced via the optimized pH-extraction and no existing compounds were completely removed from making a sensory contribution as determined by the olfactory analysis.