A study on the twin screw extrusion-cooking of plant-meat pet food mixtures

A b s t r a c t. A study was conducted on the possibility of application of “dry” extrusion-cooking technology for the processing of plant-meat mixtures. The effect of the concentration of the meat material (meat-bone pulp), leguminous material (faba bean), wheat grain meal and extrusion temperature on the process run, physicochemical properties and on the microstructure of the extrudates was investigated. It was demonstrated that extrusion-cooking with a twin-screw extruder permits the processing of blends with up to 30% meat-bone pulp content. Increase in the content of the meat material caused a decrease of specific density and water solubility index (WSI) of the extrudates. At the same time, a significant increase in the content of proteins, fat, and ash was observed. Extrusion temperature increase from 130 to 250°C caused an increase in the degree of expansion ratio and impact strength of the extrudates and a decrease in specific density of the products. At the same time, the microstructure of the products was changed from cohesive and compacted to more expanded and porous. K e y w o r d s: extrusion-cooking, faba been, meat-bone pulp, pet food, wheat