Extrusion of Andean Grains for the Food Industry: Process Optimization, Product Development and Market Opportunities

Extrusion technology has emerged as one of the most versatile processing methods for developing functional foods from Andean grains, responding to the increasing global demand for nutritious, sustainable, and gluten-free products. This review critically examines recent advances in the extrusion processing of quinoa, kiwicha, and kañiwa, with emphasis on the interactions between raw material composition, thermomechanical processing parameters, and final product functionality. The review discusses the influence of formulation strategies, extrusion conditions, and specific mechanical energy on starch gelatinisation, protein texturisation, expansion behaviour, and bioactive compound retention. Furthermore, it evaluates the application of conventional and emerging approaches, including high-moisture extrusion, artificial intelligence-based process optimisation, machine learning, and Industry 4.0 technologies, to improve process control and product quality. Current evidence demonstrates that the synergistic integration of ingredient design, extrusion engineering, and predictive modelling is essential for maximising nutritional value, technological performance, and industrial scalability. Unlike previous reviews that primarily focus on extrusion conditions or grain composition independently, this study presents an integrated techno-functional framework linking formulation strategies, extrusion parameters, nutritional outcomes, and industrial applications. This framework identifies key interactions and research gaps to support the rational design of next-generation extruded foods with enhanced functionality, improved nutritional quality, and sustainable commercial competitiveness.