Factors Influencing β‐Glucan Levels and Molecular Weight in Cereal‐Based Products

The beneficial role of soluble dietary fiber in human nutrition is well documented and has lead to a growing demand for the incorporation of β‐glucan, particularly from oats and barley, into foods. β‐Glucan with high solubility and high molecular weight distribution results in increased viscosity in the human intestine, which is desirable for increased physiological activity. Molecular weight, level, and solubility of β‐glucan are affected by genotype, environment, agronomic input, and the interactions of these factors and food processing methods. Available literature reveals that the level of β‐glucan in a finished product (e.g. bread, cake, muffins) depends upon several factors in the production chain, whereas food processing operations are major factors affecting molecular weight and solubility of β‐glucans. Therefore, to avail themselves of the natural bioactive compounds, food manufacturers must pay attention not only to ensure sufficient concentration of β‐glucan in the raw material but also to the processing methods and functional properties of β‐glucan, minimizing enzymatic or mechanical breakdown of the β‐glucans in end‐product and optimizing processing conditions. This review discusses the different sources of β‐glucan for use in human functional foods and factors affecting the levels and the molecular weight of β‐glucan at various pre‐ and postharvest operations.