Abstract: Twin-screw extruder processing was used to prepare textured soybean protein (TSP). The effects of protein, fat and starch amounts and water content on TSP quality were explored by orthogonal tests coupled with principal component analysis. In addition, TSP was used as the raw material to prepare meatballs. The effects of salt, sugar, beef perfume and monosodium glutamate on the flavor and texture parameters of meatballs were investigated. The results showed that the descending order of material components for affecting TSP quality was fat, protein, water content and starch, respectively. Meanwhile, the optimal material system was composed of 30% water, 20% soybean protein isolate, 25% potato starch, and 6% soybean oil. Moreover, the optimal flavor formula of meatballs was 4% salt, 1% sugar, 1.5% beef perfume and 1% monosodium glutamate. Texture property analysis showed that texture parameters of meatballs at the compression ratio of 50% were 6.111 kg of hardness, 0.765 of cohesion, 0.869 of elasticity, 4.113 kg of chewiness and 0.429 of resilience.

Key words: soybean protein, twin-screw, mock, extrusion, mock meatball