Nutritional and technological aspects of wheat aleurone fible: Implications for use in food

Over the last 3 decades substantial attention has been given to the role of dietary fibre in health and disease, in particular diabetes, cardiovascular disease, intestinal health and some types of cancer. This has lead to developments in the food industry to add back fibre to refined food products or develop fibre rich foods. Initially, the fibre source most frequently used was bran isolate. However, bran often has application properties, which makes incorporation in foods at higher levels difficult. During the last decade much attention has been given to the comparison of the health benefits of isolated fibres and whole grains. A number of studies suggested that whole grain foods are superior to foods enriched with bran fibre or to bran supplements. One of the arguments often put forward is that the content of bioactive components and micronutrients from whole grain may be more abundant and also more bio-available to the body compared to that of isolated fibre. This also triggered the interest in how to isolate the micronutrient rich fraction from the wheat kernel. Aleurone is a single cell layer that lies between the endosperm and the bran of the wheat kernel and contains most of the minerals, vitamins, phenolic antioxidants, and lignans. Recent data suggest that these components may provide the majority of health benefits observed in people that have a high consumption of whole grain products. Novel milling techniques have recently allowed for full-scale separation of aleurone cells from the pericarp layer of wheat bran, yielding a potential whole grain fibre concentrate which recently has been used in a variety of studies addressing its bio-actives contents, its post ingestion intestinal effects and metabolism as well as systemic effects. The present study highlights available data on aleurone isolation, composition, intestinal physiology and metabolism and potential health benefits as well as its use in food.