Extrusion cooking technology

Extrusion cooking technology is used for the manufacture of commercial dry food for canine and feline diets: about 95% of dry pet foods are extruded . In this processing technology a mixture of ingredients is steam conditioned, compressed and forced through the die of the extruder. The reason for the widespread use of extrusion cooking to produce pet diets is the versatility of this technology to mix diets and functionally improve, detoxify, sterilize and texturize a large variety of food commodities and food ingredients. A combination of moisture, pressure, residence time, temperature and mechanical shear is used for these reactions and transformations [3]. Pet food by extrusion processing focuses on the production of feeds for animals with a high nutritional value but low economic usefulness. Nonetheless, balancing the components and gentle processing are at the center of the related quality considerations. Extrusion is therefore increasingly proving to be the right tool for modern pet food.

Extrusion has become a very important process in the manufacture of pet food. Extrusion machines use single or twin screws to transport, mix, knead, shear, shape, and/or cook multiple ingredients into a uniform food product by forcing the ingredient mix through shaped dies to produce specific shapes and lengths. Extrusion provides the foundation for continuous production. Food extruders are used to produce pasta and other cold formed products, cereals, snacks, pet food, feed, confectionery products (including chewing gum, licorice, and marsh mallows), modified starches for soup, baby food, and instant foods, beverage bases, and textures vegetable proteins. Single-screw extruders have been in use for continuous cooking and in the forming of ready-to-eat (RTE) cereals as a one-step process since the 1960s. Twin-screw extruders were in common use in food production by the 1980s. A gradual shift towards prepared dog food was observed over the review period and now dog owners have been more willing to spend on food for their pet than ever before. This trend has spawned an entire industry, with a growing emphasis on dog food.