Oat proteins: A perspective on functional properties

Oats have a relatively high amount of protein content and better protein quality in terms of amino acid composition, compared to other cereal grains. Oat proteins are the by-product of the oat flour fractionation process into oat bran, oat starch and beta-glucan. The oat proteins are also unintentionally removed during the physical separation step of fibre in preparation of oat flours, oat flakes and oat milk. Hence, there is a greater need to use oat proteins as a food ingredient to minimize waste production and better utilization. But functionality and yield of oat protein concentrates and isolates varies with the extraction method. The native isolated oat proteins have good solubility and emulsifying properties at low and high pH but poor functionality at neutral and slightly acidic pH values (4-7). To maintain or improve the techno-functionality of native protein at neutral pH, chemical modifications and enzymatic hydrolysis have been reported. This review briefly describes the isolation of oat proteins and the functional properties of native and modified oat proteins. Knowledge of the techno-functionality of oat proteins is important for its application as an alternative ingredient in the dairy, bakery and meat sector and formulations of novel functional and nutraceutical food products.