Effects of Process Variables on the Physicochemical, Textural, and Structural Properties of an Isolated Pea Protein-Based High-Moisture Meat Analog

Abstract

This study investigated the optimal extrusion conditions required to produce an isolated pea protein (IPP)-based meat analog. High-moisture extrusion cooking (HMEC) was performed. The effects of the moisture content (55 and 60%), barrel temperature (165 and 175 °C), and screw speed (150 and 200 rpm) on the physicochemical, textural, and structural properties of the high-moisture meat analog (HMMA) were determined. The results showed that the moisture content had a significant effect (p < 0.05) on the physicochemical and textural properties of the HMMA. A lower moisture content had significant impact (p < 0.05) on enhancing the texturization of the HMMA and the formation of fibrous structures, thereby increasing the texture profile analysis (TPA) and cutting strength of the HMMA. Protein denaturation during HMEC resulted in a lower protein solubility of the meat analog than the raw material. The content of β-sheets and β-turns in the meat analogs were higher than that in the raw material, while the content of random coils and α-helices is inversely proportional. The process variables had no significant (p > 0.05) effect on the secondary structures. In conclusion, the moisture content is the most important factor affecting the properties of HMMAs. The extrusion process variables for HMMAs are a moisture content of 55%, a barrel temperature of 175 °C, and a screw speed of 200 rpm.