As shown in Table 1, which was largely derived from Rooney and Serna-Saldivar (2003). Corn grain is processed in many different ways around the world into various food fractions. A common feature to all of the foods derived from corn grain is cooking the grain by boiling, baking, or frying. The temperatures and duration of cooking will vary considerably. Corn grain is also steeped in alkaline or other aqueous environments and can be fermented for production of other foods (Rooney and Serna-Saldivar, 2003). More details regarding the processing conditions used to convert corn grain into various foods can be found in Appendix A, Supplementary data.
3.2. Processing of soybeans into human foods
Most of the commercial varieties of soybeans are processed into meal to feed farm animals, and soybean oil is often recovered from processed meal for human food uses. During processing, the soybeans are cracked to remove the hull and then rolled into full-fat flakes. The rolling process disrupts the oil cells, facilitating solvent extraction of the oil. After the oil has been extracted, the solvent is removed, and the flakes are dried, creating defatted soy flakes.
While most of the defatted soy flakes are further processed into soybean meal for animal feeding, the flakes can also be ground to produce soy flour, sized to produce soy grits or texturized to produce textured vegetable protein (TVP) for human food uses. Further processing can produce high protein food ingredients such as soy protein concentrates and isolated soy protein. These ingredients have functional and nutritional applications in various types of bakery, dairy and meat products, infant formulas and other soy foods (NSRL, 2010).