Modulating molecular interactions in extruded pea protein isolate

Muhialdin, B. J.*; Sanchez, C. F.*; Nakagawa, Hiroshi   ; Ubbink, J.*

The impact of molecular interactions on the physical properties of extruded pea protein isolate (PPI) is investigated by adding interaction-modulating compounds to the matrix premix and studying the resulting variations in mechanical and physicochemical properties. Blends of PPI containing either sodium phosphate, urea, sodium dodecylsulphate and beta-mercaptoethanol, as well as with all four compounds and only with deionized water were extruded into thin strands using a lab-scale twin-screw extruder. The hardness from texture profile analysis was the lowest for matrices extruded with beta-mercaptoethanol and with all four chemicals, and highest for the control sample. The water holding capacity of the matrices is lowest for the beta-mercaptoethanol-containing matrix. Our results confirm the importance of disulfide bonds in texturized PPI and show that hydrophobic and electrostatic interactions play auxiliary roles in modulating the properties of extruded PPI matrices.