Background
Gluten is the main storage protein of wheat grains. Gluten is a complex mixture of hundreds of related but distinct proteins, mainly gliadin and glutenin. Similar storage proteins exist as secalin in rye, hordein in barley and avenins in oats, and are collectively referred to as “gluten”.
Objective
The objective was to discuss the biochemical and functional properties of the gluten proteins, including structure, sources, and dietary intakes.
Design
Literature was reviewed from peer-reviewed food science and nutrition journals.
Outcomes
The gluten protein networks vary due to their different components and sizes, and the variability caused by genotype, growing conditions and technological processes. The structures and interactions of this matrix contribute to the unique properties of gluten. The resulting functions determine the dough quality of bread and other baked products. Gluten is heat-stable and has the capacity to act as a binding and extending agent, and is commonly used as an additive in processed foods for improved texture, moisture retention and flavour. Gliadin contains peptide sequences that are highly resistant to gastric, pancreatic and intestinal proteolytic digestion in the GI tract. The average daily gluten intake in a Western diet is thought to be 10-20 g/day. While wheat-containing bread is one of the major sources of gluten, there is some evidence that exposure to gluten may be increasing with changes in cereal technology.
Conclusion
Gluten containing grains (wheat, rye, barley, oats) are important staple foods. Gluten is among the most complex protein networks and plays a key role in determining the rheological dough properties and baking qualities.
Source of funding
Not applicable.