Physicochemical and Sensorial Evaluation of Meat Analogues Produced from Dry-Fractionated Pea and Oat Proteins

Pea protein dry-fractionated (P_DF), pea protein isolated (P_Is), soy protein isolated (S_Is) and oat protein (O_P) were combined in four mixes (P_DF_O_P, P_Is_O_P, P_DF_P_Is_O_P, S_Is_O_P) and extruded to produce meat analogues. The ingredients strongly influenced the process conditions and the use of P_DF required higher specific mechanical energy and screw speed to create fibrous texture compared to P_Is and S_Is. P_DF can be conveniently used to produce meat analogues with a protein content of 55 g 100 g^-1, which is exploitable in meat-alternatives formulation. P_DF-based meat analogues showed lower hardness (13.55-18.33 N) than those produced from P_Is and S_Is (nearly 27 N), probably due to a more porous structure given by the natural presence of carbohydrates in the dry-fractionated ingredient. P_DF_O_P and P_Is_P_DF_O_P showed a significantly lower water absorption capacity than P_Is O_P and S_Is_O_P, whereas pea-based extrudates showed high oil absorption capacity, which could be convenient to facilitate the inclusion of oil and fat in the final formulation. The sensory evaluation highlighted an intense odor and taste profile of P_DF_O_P, whereas the extrudates produced by protein isolates had more neutral sensory characteristics. Overall, the use of dry-fractionated protein supports the strategies to efficiently produce clean-labeled and sustainable plant-based meat analogues.

High moisture extrusion of lupin protein: influence of extrusion parameters on extruder responses and product properties

BACKGROUND

High moisture extrusion (HME) of lupin protein concentrate and isolate (50:50) mixture was performed by varying the extrusion parameters, such as barrel temperature (138-180 °C), water feed (40-68%) and screw speed (400-1800 rpm). The effect of extrusion parameters on extruder responses [die pressure, product temperature, torque and specific mechanical energy (SME)] and product properties [colour, cutting force, cooking yield, microstructure and in vitro protein digestibility (IVPD)] was evaluated.

RESULTS

The multiple regression analysis of the results revealed that the water feed had a significant negative linear effect on the extruder responses considered, as well as on colour difference and cutting force of extrudates. Screw speed had a positive linear effect on product temperature, SME and cooking yield. Barrel temperature affected extruder responses and product properties to a lesser extent. Scanning electron microscopy showed that denser microstructure and higher number of fibre layers were created by increasing temperature and screw speed along with decreasing water feed. The results of IVPD of selected extrudates showed that the increase in barrel temperature decreased the IVPD, whereas the increase in water feed resulted in higher IVPD. The screw speed had no significant effect on IVPD.

CONCLUSION

The study demonstrates that the use of lupin protein is feasible to produce meat analogues with HME which could enhance the possibilities to meet the growing protein demands for human consumption. © 2018 Society of Chemical Industry.