Combined effects of twin-screw extrusion parameters on physical, morphological, and microstructural properties of cassava-based analog rice

The production of analog rice has emerged as a potential approach for food fortification and diversification, particularly for populations that depend on rice as a staple food. Although the production of analog rice through extrusion has been widely practiced, detailed scientific studies on the process mechanisms are rare. Furthermore, the use of cassava flour as a raw material for analog rice is rarely documented because of its sticky characteristics. This study analyzed the effects of extrusion process parameters using a twin-screw extruder, such as barrel input temperature, dough water ratio, and screw speed, on the physical characteristics of the resulting cassava-based analog rice. This study demonstrated that the combination of extrusion parameters plays a critical role in determining the quality of cassava-based analog rice by significantly influencing bulk density, brightness, hardness, and moisture content. The extrusion process conditions at an input barrel temperature of 80 °C, 40% water addition, and a screw speed of 600 rpm showed the best characteristics, with an analog rice density of 0.628 g/mL, a brightness of 69.26, a moisture content of 3.03%, and a hardness of 2041 kg of cooked analog rice. The extrusion process conditions also play a role in the formation of the analog rice microstructure, its porous structure, consistent with its low bulk density compared to rice. These findings contribute significantly to the understanding of multivariate interactions in the extrusion process and provide a foundation for developing cassava-based analog rice on an industrial scale.