Decoding the odor profile of pea protein isolate: A multidimensional exploration based on GC-O-MS, GC × GC-O-TOF-MS, and GC-IMS

In light of the diversity and complexity of pea flavor, the odor profile of pea protein isolate (PPI) has not been comprehensively characterized. This study aims to explore the odor profile of PPI by SPME and SAFE coupled with multidimensional flavor analytical approaches, including GC-O-MS, GC × GC-O-TOF-MS and GC-IMS analyses. A total of 148 volatile compounds were detected by all three analytical techniques, with over 80% being identified by GC × GC-O-TOF-MS. Furthermore, 42 odor-active compounds were identified by GC-O/GC × GC-O analyses, among which 2, 3-octanedion, butyl acetate and ethyl acetate showed odor activity in PPI for the first time. Subsequently, these 21 odorants with flavor dilution (FD) factors ranging from 9 to 243 were quantified by external standard curves and their odor activity values (OAVs) were calculated. Notably, (E, E)-2,4-decadienal exhibited the highest OAV, followed by hexanal and nonanal, which all contributing the typical fatty and grassy odors to PPI. Finally, the contribution of 20 key odor-active compounds with OAV >1 to the odor profile of PPI was further validated through a reconstitution experiment. These findings provide basis for the flavor analysis and sensory improvement of pea-derived products.