Dietary Arabinoxylans in Grains and Grain Products
Arabinoxylans are the predominant non-cellulosic polysaccharides of primary and secondary cell walls in all the major cereal grains. Arabinoxylans may constitute a significant portion of human dietary fibre intake, given that they occur in most commonly used cereal grains and grain-based foods and beverages. The interest in arabinoxylans originated from several physicochemical properties of these polysaccharides, including viscosity enhancement, gel formation, and emulsion and foam stabilization. Arabinoxylans influence the use of cereal grains in milling, brewing, food manufacturing, animal feed production and in many non-food applications, including pharmaceutical, cosmetic and biofuel production. As constituents of dietary fibre, arabinoxylans have an impact on the nutritional quality of cereal foods; they offer the health benefits of soluble and insoluble fibre, inducing positive effects on colonic health, lipid metabolism and glycaemic control. The most recent interest in arabinoxylans stems from evidence that arabinoxylans play a part in modulating and supporting the immune system. The genotypic and cellular origins of arabinoxylans affect their molecular structure and size, and influence their physiological efficacy. A better understanding of the relationship between the molecular structure of arabinoxylans and their bioactivity is needed to effectively, safely and precisely target and predict the specific physiological effects of these naturally occurring polysaccharides.