Delivering high dietary fibre via improved wheat cultivars and products

Dietary fibre (DF) is essential for human health, improving gastro-intestinal function and reducing the risk of a range of chronic diseases (including type 2 diabetes, cardio-vascular disease and types of cancer). However, most UK consumers do not eat DF, with the average daily intake being 17.2 g for women and 20.1g for men, compared with a target of 30g. Cereal products are the major source of DF in the UK diet, with bread alone contributing about 20%. However, the contribution from wheat is limited by the fact that most wheat products are made from white flour, which contains about 3.5% DF compared with 11.5-15.5% in wholemeal.
We have therefore identified wheat lines with high DF in white flour, which can be used to develop high fibre wheat lines for UK farmers and products for UK consumers. The proposal will remove the constraints to the development of high fibre lines and products in the UK, by collaborating with four wheat breeders, 2 milling and baking companies and the organisations representing the milling (NABIM) and baking (Federation of Bakers) sectors.
This will be achieved in two ways: by providing high fibre pre-breeding lines and molecular makers to wheat breeders, and high fibre lines to millers and bakers to optimise their processes. These advances will be disseminated by the BBSRC Designing Future Wheat programmes and by NABIM and FoB.
It will therefore have a fundamental impact on the diet and health of UK consumers.

This LINK proposal will remove the constraints to the development and utilisation of wheat with high arabinoxylan (AX) fibre in white flour.
This will be achieved by:
1. Developing and validating markers for QTLs for high fibre in white flour identified on chromosome 1BL and 6BS in the cultivars Yumai 34 (Chinese) and Valoris (French), respectively.
2. Introgressing these QTLs into elite UK germplasm to develop pre-breeding lines suitable for incorporation into breeding programmes in the UK.
3. Fine mapping the 1BL QTL to develop improved markers and identify recombinants to facilitate further introgression.
4. Determining the effects of high AX in flour on the milling and breadmaking properties, using pre-breeding lines in elite UK cultivars.
5. Determining the effects of environment on the content of AX in flour of pre-breeding lines and the impact of this variation on processing properties.
6. Disseminating this information to breeders, farmers, grain processors and consumers.

The importance of dietary fibre (DF) in human health is recognised globally, including the potential of increasing fibre intake in dietary interventions to reduce the risk of chronic diseases. Cereals are the major source of dietary fibre in many countries, with wheat being the most important in temperate countries. For example, about 40% of the fibre in the UK diet comes from cereals, with about half of this coming from bread and a quarter from white bread. Wheat, and in particular bread, is therefore also recognised as an attractive vehicle to increase fibre intake, particularly by increasing the consumption of whole grain products. However, although the heath benefits of wholegrain products have been widely promoted, their consumption in many countries remains low, due to cultural preferences and their undesirable organoleptic properties. For example, over 80% of the flour used for bread making in the UK is white. Hence, it is important to increase the fibre content of white flour, in order to deliver benefits to the wider population.
Increasing the fibre content of white flour made from wheats grown in the UK is therefore expected to have significant benefits to the health and quality of life of the UK population. Because the results will be readily exploited in other countries a much wider global impact is expected.