Rheological properties of pea protein melts used for producing meat analogues

Abstract Understanding the rheological properties of protein melts is critical in the design of meat analogues and the formation of texturised products from plant-based proteins. This study investigated the influence of temperature, moisture content (MC) and protein concentration on the rheological properties of pea protein isolate and pea fibre blends. The blends were chosen as an experimental space where it is possible to extrude fibrous meat analogues using high-moisture extrusion. Mechanical spectra by small amplitude oscillatory shear were determined using conventional rheometry and were compared to closed cavity rheometry (CCR) to extend the available temperature range. All blends behaved as polymer melts in the rubbery region with moduli increasing with frequency, and storage modulus larger than loss modulus for temperature 40–90°C, MC 54–63%, protein concentration 75–85%. Complex viscosity was strongly shear thinning. The relative influence of the parameters from additive and linear mixed models showed an influence of temperature > MC > concentration. The increase of modulus with concentration was quite weak and not statistically significant. The behaviour of the complex modulus was explained well with an Arrhenius-type log-linear mixed model. Conventional rheometry agreed well with CCR, showing an exponential decrease of moduli between 40 and 130°C.