Cereal beta-glucans: an underutilized health endorsing food ingredient

Cereal β-glucan describes a group of soluble dietary fiber primarily found in barley and oats. It is characterized by the mixed occurrence of β-(1,3) and β-(1,4) bonds between the glucose monomers, forming long polysaccharide chains with unique properties. Alongside their technological benefits, they exhibit a number of health–beneficial properties. Nevertheless, β-glucan applications as nutraceutical food ingredient, are rarely utilized. The changes in physicochemical (molar mass, solubility and viscosity) and health–beneficial (glycemic control, lowering of blood glucose) properties during food processing and storage are a major drawback. The understanding of the complex mechanisms behind the health benefits of β-glucan is still incomplete. In contrast to original believes, it becomes evident from recent literature, that physiological properties are not only based on the dose administered. A more thorough view on the molecule and its structure–size–function relationship is required to understand the impact of molar mass, molar ratio, solubility and viscosity. Therefore, this review evaluates the recent scientific data to identify β-glucan key properties responsible for the nutraceutical function in the final product. This provides a guideline for future research which characteristics need careful monitoring and preservation throughout processing and help to fully utilize cereal β-glucan as nutraceutical ingredient.