Two goals of research under the Enhanced Profitability Program of IMBA are:
- To develop new and improved uses for corn and soybeans.
- To increase the value of these crops as raw material for manufacturing various products.
The overall goal of this project is to develop a high quality, nutritious meat analog with a meat-like fibrous structure and texture using soy protein and cornstarch. The project contributes to these two goals and will add significant values to corn and soybeans by using them as the major raw ingredients for this new product.
Currently, most meat analogs made from soy proteins are processed primarily by two methods: Wet fiber spinning and thermoplastic extrusion. Average moisture content is around 30% using single-screw extruders.
Wet fiber spinning involves dissolving protein isolates in an alkali aqueous solution, forcing this protein dispersion through a porous device, such as a spinnette used in the production of rayon, and then passing into a coagulating bath. The streamlets coming through the spinnette are precipitated into fibers. Many further steps are needed. Resulting products are good in quality but high in production costs.
Thermoplastic extrusion forms meat-like protein products using single-screw extruders. Defatted soy flake or flour is mixed with other ingredients. The resulting composition is extruded at approximately 177 degrees Centigrade. Products expand rapidly upon emerging from the die. Meat analogs must be rehydrated with water or flavoring liquids. Spongy structure produces product with poor flavor retention and lack of real fibrous texture.
This project seeks ways to use high-moisture twin-screw extrusion to develop high quality meat analogs using soy protein and cornstarch that are far superior to the methods explained above and at a commercially viable price.
Protein texturization during high-moisture twin-screw extrusion is a combination of a series of chemical and physical processes. Process conditions and die design play important roles on the formation of fibrous structure and meat-like texture of the resulting products. Extensive work on chemical and physical processes will be performed. Specific objectives are:
- To investigate critical factors that limits the production rate and commercial scale-up of soy protein-corn starch meat analog.
- To elucidate the mechanisms of protein texturization during high-moisture twin-screw extrusion of meat analog.
In recent years there has been increased interest in soy food consumption because a number of epidemiological studies have suggested that consumption of soy foods is associated with lowered risks for cardiovascular diseases, bone loss and several cancers.
Today, many soy products provide protein in nutritional forms, such as powders in health stores. However, these products are often unacceptable to the larger public because of taste and texture.
This work seeks to discover manufacturing ways of providing the public with lower cost, highly palatable soy protein-based foods such as meat analogs. The demand for soybeans should expand. Agriculture and public health should benefit.