Extrusion of Plant Raw Materials in Food Production: A Review

Introduction. The present review covers the issues of extrusion of plant raw materials in food industry. The authors analyzed foreign publications about various extrusion technologies, their rational parameters, and their effect on the properties of final products. Study objects and methods. The research featured extrusion methods of plant raw materials in food production. The review included scientific articles published in English in 2000–2020. Results and discussion. Extrusion is an effective processing method for plant raw materials in food industry. The analysis made it possible to define the effect of extrusion parameters on the components of plant raw materials. Extrusion increases digestibility of such plant components as protein and starch. High temperature, speed, and moisture are the optimal parameters for extrusion. High barrel temperature has a negative effect on vitamin and carotene content, while feed rate and screw speed are not important. Extrusion leads to complete mycotoxins reduction at critical temperatures. While high temperature and screw speed are important for process efficiency, they have a negative effect on the nutritional value of the final product. Conclusion. Optimal parameters of various raw materials and their compounds remain largely understudied, in spite of the fact that they are responsible for the balance between the required extrudate properties and nutritional value. Formation of nutrient complexes and their effect on the process parameters also require further research, especially in regard with protein-carbohydrate and amylaselipid complexes. In general, extrusion of plant raw materials remains a promising but largely neglected research topic in food science.