Wheat Bran Proteins

Abstract

Wheat pericarp, known as bran after milling, is the protective envelope of the grain. It is constituted by seven layers, grouped into three major sections: inner (aleurone), intermediate, and outer bran, respectively. Thousands of proteins are expressed during the wheat grain development, many of them in pericarp, so wheat bran protein content is 15%. Aleurone proteins are mostly storage and metabolic enzymes, while those of intermediate and outer bran layers are mainly involved in stress/defense. Bioactivity of wheat bran proteins has been scarcely explored. Some evidences suggest a role in regulating fat metabolism, which could be preventive of obesity and nonalcoholic fatty liver disease. Antihypertensive peptides have been isolated from wheat bran, as well as soluble proteins of low molecular weight with antibacterial properties. Other uses for wheat bran protein extracts, such as enzyme inhibitors in food processing or as reservoirs of proteins for nanoparticle self-assembly, are discussed.