Extruded Food Production Method

Extruded food production involves a complex process of mixing, crushing, cooking, sterilizing, forming and partial dehydration of cereal raw materials and ingredients within a single screw extruder. This technique is more efficient than the traditional method of grain food processing as it significantly reduces the number of equipment required and the area they occupy. This, in turn, reduces the investment needed and ultimately results in lower production costs, especially when using twin-screw extruders. Another advantage of this method is that it enables the production of unique product shapes that are not easy to achieve through any other means, leading to the creation of novel food varieties. Overall, extruded food production represents a creative way to optimize resources while broadening the range of food products available to consumers.

Extrusion cooking is a process that involves subjecting the material to high temperatures of up to 180-200℃ for a short period of 5-10 seconds. Therefore, it is often referred to as a high-temperature short-time process. During this process, the starch in the material undergoes gelatinization, while protein is denatured. The result is increased food digestibility and fast food preparation. Additionally, anti-nutritional factors and toxic components in the raw material, such as trypsin in soybeans and gossypol in cottonseed, are destroyed by the cooking process. Enzymatic activity that can lead to food deterioration also gets deactivated, while unpleasant flavors in raw materials are removed. These benefits make extrusion processing a critical method for processing cereal foods.

The use of an extruder in producing non-expanded extruded food goes back to the early 1900s when macaroni was made using plunger and screw extruders. However, it was not until the 1930s that instant cereals were first made using extruders by the American General Flour Milling Company. Adams Company realized commercial production of extruded corn fruit in 1946. The extrusion process for processing whole-grain soybeans into full-fat soybean meal was first developed in 1959 by Wenger Company of the United States. In the 1960s, industrial research labs like Archer Daniels Mitland used extrusion cooking to make tissue vegetable protein from soybean meal powder. This period also saw the rapid development of instant grain foods and nutritious mixed foods produced by extruders. Later on, in the late 1970s, France's Cresso-Roa Company invented a twin-screw extruder that expanded the range of raw materials and product varieties used for extruding food.