Characterization and functional properties of pH- and heated time-induced aggregates from red lentil protein

In this study, red lentil isolate protein (RLPI, 3 %, w/v) was treated at pH 2 and 7 at 85 °C for a period of 0–24 h. The TEM and SDS-PAGE results indicated that the molecular weight of RLPI was steadily reduced and hydrolyzed into peptides over the prolonged heating time, eventually forming fibrillar and particulate aggregates at pH 2 and 7, respectively. The FTIR results showed an increased level of the proteins’ random coil motifs due to the excessive heating. According to the results of emulsifying properties, the emulsifying capabilities of fibrillar proteins were higher than those of the particle proteins at the same protein concentration due to the proteins’ structure and their surface charge. Notably, the fibrillar aggregates formed a gel network structure and stronger interactions in fibrillar aggregates compared to the particulate aggregates at pH 2. This study provides references for the processing and utilization of plant proteins in beverages and dietary supplements.