Insects in Extruded Products

The extrusion of edible insects opens numerous opportunities for developing insect food products with various textures. This chapter outlines two extrusion approaches used for edible insects, namely, high-moisture and low-moisture extrusion. High-moisture extrusion leads to the formation of fibrous structures mimicking meat fibers by texturization of protein-rich (insect) materials. Low-moisture extrusion results in diverse porous structures. The latter can be used as final food products or further rehydrated to obtain minced meat-like structures. Insect extrudates can be used in various food applications for daily consumption, such as meat substitutes, snacks, cereals, and others. The quality characteristics of extruded insect products are determined by the type of extrusion, conditions, degree of insect processing before extrusion (insect powder, insect protein), insect species, and the quality and ratio of insect and other ingredients in formulations. The chapter describes general principles for selecting these conditions based on the targeted food application and elaborates on their effects on the nutritional value, textural, and organoleptic properties of the extrudates. Also, commonly used quality assessment methods suitable for high- and low-moisture extrudates are described. The chapter also discusses technological challenges and opportunities for the extrusion of edible insects. The current market demonstrates a high demand for extruded products, as well as high-protein foods. Edible insects can meet this demand and offer a more sustainable alternative to widely used plant proteins (soy, pea, etc.). Also, extrusion processes can accelerate the incorporation of insects into the human diet, as they can be provided in non-recognizable shapes, increasing their acceptability by consumers.