High Moisture Extrusion Process Parameters Optimization of Pea Protein Isolate and Study on Its Texture Properties

Compared with low-moisture textured proteins with poor texture and taste, high-moisture textured vegetable proteins (HMTVP) show a fibrous structure and taste similar to animal meat. Being known as a new generation of vegetarian meat products, HMTVP are becoming ideal substitutes for animal protein. Dual-screw extrusion technology was used to prepare high moisture textured proteins taking pea protein isolate (PPI) as material. The effects of process parameters (moisture content, cooking temperature, feeding speed, and screw speed) on the macro and microstructure, texture, and sensory properties of the extrudates were explored. At the same time, an orthogonal experiment was designed and principal component analysis was used to optimize the operating parameters of the extrudates closest to animal meat. The results showed that the moisture content was the key factor to improve the texturization degree and texture of PPI extrudates. The increase of moisture content increased the texturization degree and color of PPI extrudates, and significantly reduced the hardness and chewiness of the extrudates. When the moisture content was too high (65%) or too low (45%), extrudates showed poor fibrous structures. When extruded at 140 ℃ to 160 ℃, the PPI extrudates exhibited the better texturization degree, taste, appearance and color. With the increase of the screw speed, the texturization degree of extrudates significantly decreased first and then increased. When feeding speed was increased, the hardness and chewiness of the extrudates significantly increased first and then decreased, while texturization degree decreased first and then increased. Through orthogonal experiment combined with principal component analysis, the optimal processing parameters established were by taking the texture parameters of beef cucumber strips as the target parameter moisture content of 55%, cooking temperature of 160 ℃, screw speed of 175 r/min, and feeding speed of 7 g/min. The results aimed to provide technical support for the quality control of high-moisture textured vegetable proteins.