Techno-functional properties and structural changes of pork myofibrillar protein with faba bean protein isolate at...

This study was performed to evaluate the effect of faba bean protein isolate (FBPI) on the techno-functional properties and the structural changes of the pork myofibrillar protein gels (MPGs) under various pH conditions.

Control (without FBPI) and FBPI-added treatments with pH adjusted to 6.00, 6.25, or 6.50 were prepared: control groups (C6.00, C6.25, and C6.50) and FBPI-treated groups (F6.00, F6.25, and F6.50), respectively. The experimental analysis included cooking yield, gel strength, protein surface hydrophobicity, sulfhydryl group, electrophoretic protein profile, and microstructure to evaluate the techno-functional properties and structural changes in the protein matrix.

Cooking yield and protein surface hydrophobicity increased with pH; values were higher in C6.50 (91.3% and 31.3 μg) than in C6.00 (86.9% and 26.9 μg). Shear stress values remained consistent among FBPI-treated groups, whereas those of the control groups tended to increase with the adjusted pH level. Electrophoretic protein profiles revealed two distinct bands at 42 and 50 kDa in FBPI-added treatments, which were absent in the control groups; the intensity of these bands increased with the pH level. The F6.50 group presented a more compact three-dimensional protein network, and the increased intensities of the 42-50 kDa bands, corresponding to 7S and 11S globulins, correlated with the structural compaction of the gel matrix.

FBPI improved the techno-functional properties of MPGs, regardless of the adjusted pH levels. In addition, the incorporation of FBPI into MPG was associated with pH-dependent structural changes in the protein and gel network, as observed by the protein profile and microstructure.