Throughput-driven control of fibrous, anisotropic structure and texture development in high-moisture soy extrudates

• Throughput affects high moisture extrudate texture and structure • Increasing throughput lowered specific mechanical energy and mean residence time • Moderate throughput (3.6-4.2 kg/h) increased extrudate hardness and fibre thickness • Higher melt pressure correlated with thicker fibres formed in the extrudates • Excessive throughput (4.7 kg/h) led to air pocket formation and weaker texture The texture and structure of many plant-based meat analogues remain key barriers to consumer acceptance. Conventional strategies to improve fibrousness, such as adding texturising agents or modifying formulations, can increase costs and may still fall short of delivering a meat-like texture. This study systematically examines throughput (total feed rate) as a key process variable influencing the structure of high-moisture extrudates. Recognizing that industrial demands for high productivity can compromise product quality, this study systematically evaluates how throughput modulates the thermomechanical environment. By examining throughput as a key process parameter, we aim to identify the optimal window for maximizing both structure and texturization in high moisture extrudates. Soy protein concentrate (SPC) was extruded at 60% moisture and 140°C using a lab-scale co-rotating twin-screw extruder, with throughputs ranging from 2.1 to 4.7 kg/h. Increasing throughput initially favoured the formation of thicker fibres and increased the extrudate's fibrousness up to 3.6 kg/h, after which the extrudate’s fibrousness decreased. Furthermore, rising throughput initially increased the extrudate’s hardness, chewiness, and longitudinal cutting strength. However, at 4.7 kg/h, these properties declined, and air pockets formed, suggesting that excessive throughput reduces residence time and lowers specific mechanical energy, thereby limiting protein unfolding and network formation. High levels of texturization were achieved within a throughput range of 3.6–4.2 kg/h during lab-scale extrusion. These findings highlight the critical role of throughput optimisation in balancing energy input and residence time, offering a scalable, cost-effective, and process-based approach to fine-tune the texture and structure of high-moisture extrudates.