Submitted to: Journal of Food Processing and Preservation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 15, 2011
Publication Date: N/A
Interpretive Summary: Many puffed snack products and some ready-to-eat cereals are made using food processing machines called extruders. The extruder consists of a long, heated barrel with two mixing screws inside that mix and push food materials such as corn meal, cheese whey, or soy proteins through its barrel to a restricted end point where pressure builds and forces the molten food to expand. This study discussed the cost of using a twin screw extruder to create three different products: a whey protein ingredient, snacks enriched with a whey protein-ingredient, and a corn soy blend product used for emergency feeding purposes. We determined that using the twin screw extruder adds about thirty cents ($0.30/kg) per kilogram of product. The largest portion of the costs come from the ingredients, which for whey proteins ranged from $0.67 /kg to $11.63 /kg, and for corn soy blend from $0.45 /kg to $0.55/kg. From this study, we know that a whey ingredient, whey-ingredient enriched snack, or a ready-to-eat corn soy blend can be made at reduced costs using a twin screw extruder.
Technical Abstract: The operating costs associated with twin screw extrusion cooking of various foods are fixed for a given size and production capacity for any class of products; the greater percentage of costs arise from the choice of ingredients and the product end use. For example, extruder texturized whey proteins (TWP) is a new class of ingredients with expanded functionality and range of applications such as in protein-enriched snacks. The cost to produce twin-screw extruder texturized whey proteins was estimated to range from $0.67/kg to $11.63/kg depending on the protein concentration of the whey and the other ingredients. Texturizing whey protein is advantageous because it expands the range of its functionality, compatibility, and interactions with other food ingredients more than the ordinary spray dried whey protein powder. Extrusion cooking was also applied to a type of raw product purchased by the U.S. government for emergency feeding overseas under the Food-for Peace program (P.L. 480 Title II program). The food, a mixture of corn, soy protein concentrate, and soybean oil, and minerals blend (Corn-Soy Blend, CSB) could be produced from $0.45 to $0.55/kg. Overall, extrusion cooking of texturized whey proteins or corn soy blended added only $0.02/kg of product.