Structure, texture and protein digestibility of high moisture extruded meat alternatives enriched with cereal brans

Abstract

This study investigated the effects of including 5, 10 or 15% of oat bran, wheat bran, or combination of both on the physicochemical properties of extruded pea protein-based meat analogues. The extrudates were analysed for colour, textural properties, microstructure, protein-protein interactions and protein solubility. In vitro protein digestibility (IVPD) was analysed from intermediate and end products. IVPD varied between 48 and 91% and was highest in PI flour and lowest in PI extrudate. Higher tensile and cutting strengths were observed in one direction which is a typical feature of meat fibres. Bran inclusion mainly decreased both tensile (by 2–51%) and cutting (by 12–50%) strengths indicating weaker structures. Both non-covalent and disulphide bonds were observed to have a role in the structural stabilisation of meat analogues. The inclusion of brans did not have significant effects on protein-protein interactions or IVPD. In conclusion, bran inclusion may contribute to texture improvement and intake of dietary fibre without compromising protein bioaccessibility.

Keywords

• Extrusion
• Protein fibrillation
• Dietary fibre
• Pea protein
• Cereal brans
• In vitro protein digestibility