Influence of Maillard reaction conditions on the formation and solubility of pea protein isolate-maltodextrin conjugates in electrospun fibers

Electrospinning is used to structure proteins and polysaccharides into fibers prior to the formation of glycoconjugates upon heat treatment. The aim of this study was to investigate the glycation of pea protein isolate (PPI) with maltodextrin in electrospun fibers under different reaction conditions. Electrospun fibers were produced from aqueous spinning dispersions made with PPI, maltodextrin DE 2, and maltodextrin DE 21 and had a protein content of 4.49% w/w. After heat treatment (12/24 h, 65/70 °C, 75% relative humidity), the browning index of the fibers increased with increasing heating time and temperature. Higher temperature and longer heating time also promoted the glycation reaction represented by the decrease of free lysine groups and the formation of Amadori products. Generally, the extent of glycation was similar for fibers heated at 65 °C/24 h and 70 °C/12 h. Analysis of the molecular weight with SDS-PAGE and SEC revealed increasing molecular weight upon heating. The isoelectric point of the fibers shifted from pH 4.05 ± 0.13 to pH 3.02 ± 0.16 (70 °C/24 h). Protein solubility generally increased upon glycation. Overall, results indicate that glycation of PPI with maltodextrin in electrospun fibers is able to improve their technofunctional properties.