Overview of Expanded and Extruded Products

Grains are widely recognized for their nutritional properties and adaptability, making them ideal for applications in the snack industry such as extruded and expanded products. The extrusion process focuses on developing starchy products in two ways: either by incorporating sub-products into the composition or by incorporating different grains or pseudocereals, such as corn, rice, oats, barley, or wheat, to boost their nutritional value. Otherwise, literature on expanded products, known also as puffed products, is more limited. The food market primarily perceives puffed products as wholesome breakfast grains, bars, or cakes. While the extrusion and puffing processes may appear similar in terms of how pressure, time, and temperature affect the final product's quality, they differ from other significant perspectives, which we will delve deeper into. This review will provide a better understanding of the differences and similarities between expansion and extrusion processes, focusing on two important grains for this industry, corn and rice.