Extrusion For Food

Extrusion is a high temperature, short time (HTST) process that inactivates enzymes and reduces microbial contamination. Since extrusion is a high temperature, short time (HTST) process that reduces microbial contamination and inactivates enzymes, the main preservation method for hot and cold extruded foods is to take advantage of the low water activity of the product. Relatively speaking, the process uses less water than traditional baking or dough processing. Typical moisture content is between 10% and 40% on a wet weight basis. This technology has some unique advantages over other thermal processing processes because the material is subjected to intense mechanical shear. Extruders use pressures of 15 to 200 atmospheres to regulate the shape, keep the water in a superheated liquid state, and enhance shear in specific types of screws.

Currently, and in the future, the most difficult and demanding areas are health and nutrition. Research on preserving and enhancing the nutritional value of food during processing has always been of vital importance. A challenge of most traditional cooking techniques is the loss of nutritional quality at high temperatures. Extrusion cooking outperforms other food processing techniques in terms of continuous processing, high productivity and significant nutrient retention due to the high temperatures and short times required. Food extruders can be designed to perform multiple unit operations simultaneously, including mixing or homogenization, shearing, starch gelatinization, protein denaturation, texturization, enzyme inactivation, thermal cooking, pasteurization, dehydration, forming and size reduction.