Upcycling of cereal by-products to produce value-added food protein ingredients

Cereal processing results in the generation of around 13% of all food waste globally such as germ and bran. Conversion of cereal by-products into value-added food ingredients can make positive contributions to achieving sustainable food systems and reducing negative impact on environment. Among cereals, rice, wheat, barley, and maize account for over 90% of cereal consumption. In this presentation, our recent research progress on valorization of proteins from defatted wheat germ and corn gluten meal will be discussed.

First, we used different food-grade proteases to produce defatted wheat germ protein hydrolysates (DWGPH). In vitro study demonstrated DWGPH effectively inhibited Helicobacter pylori (H. pylori) adhesion to gastric epithelial cells, which showed potential for the prevention of H. pylori infection. H. pylori is categorized as a class I carcinogen by the World Health Organization (WHO). We further determined emulsifying and emulsion-stabilizing properties of DWGPH to identify peptides with dual functionality using in silico and in vitro assays. These results suggested that DWGPH is a promising candidate for development as a dual-functional food ingredient. In addition, low protein digestibility of corn gluten meal (CGM) limits its applications in human food. Therefore, our recent work aimed to evaluate the impact of starch removal and different thermal processing methods (microwave, extrusion, boiling, and baking) on in vitro protein digestibility of CGM, and reveal the underlying possible mechanisms by examining the changes of the physicochemical and structural properties of treated CGM. The results suggested that starch removal has significantly increased protein digestibility by 26.3% to 37.8% compared to samples with starch (P< 0.05).

In conclusion, our research contributes to adding value to cereal by-products, opening new avenues for their utilization as alternative protein sources.