Wheat Preprocessing Methods to Improve Nutritional and Technological Functionality

摘要

All wheat-based products require preprocessing of the grain before they can be used as food ingredients. Preprocessing techniques, both physical and biochemical, affect the nutritional value and techno-functionality of wheat in different ways and are the subject of this review. Physical techniques, such as milling, dry heating, and extrusion, improve the nutritional properties of wheat by increasing the digestibility of starches and proteins. However, care needs to be taken to not induce extensive protein cross-linking or damage heat-sensitive vitamins when using these methods. Biochemical methods, such as enzyme treatments, sprouting, and fermentation, are less harsh. These methods also can increase the nutritional value of wheat: micronutrients (e.g., vitamin levels, mineral bioavailability) especially benefit from biochemical treatments. With regard to techno-functional properties, physical treatments increase functionality by improving the baking properties of flour (e.g., starch gelatinization). Sprouting and fermentation treatments can be less beneficial due to increased enzyme activity, which can be challenging to control. Enzyme activity that is too high results in poor bread quality. Most of the research on the techno-functionality of wheat has focused on bread applications, while other bakery products, such as cake, have not been investigated as thoroughly. These types of products, however, also could benefit from pretreatment to create products with higher nutritional values while maintaining desired eating qualities.