Developing novel types of low protein wheat for breadmaking

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Nitrogen fertiliser is essential to sustain wheat yields but is also an important determinant of grain quality. This is because nitrogen is required for the synthesis of grain proteins, with the gluten proteins forming the major grain protein fraction. About 40% of the wheat produced in the UK is used for food production, particularly for making bread and other baked products. Wheat is also widely used as a functional ingredient in many processed foods, while bread wheat and imported durum wheats are used to make noodles and pasta, respectively. The gluten proteins are essential for these uses, providing visco-elastic properties to dough. Consequently, the content and quality of the grain proteins affect the processing quality, with a minimum of 13% being specified for the Chorleywood Breadmaking Process (CBP) which is used for over 80% of the "factory produced" bread in the UK. The requirement of nitrogen to produce wheat for bread making is also above the optimum required for yield, and farmers may apply up to 50 kg N/Ha above the yield optimum to achieve 13% protein (2.28% N). This is costly with nitrogen fertiliser contributing significantly to crop production, and may also contribute to a greater "nitrogen footprint" in the farmed environment. It may be possible to reduce the requirement for breadmaking wheats, to a limited extent, by optimising the efficiency of nitrogen uptake and use within the wheat plant. However, this will only have limited benefits and a more viable long-term solution is to develop new types of wheat and processing systems which will allow the use of lower protein contents for bread making. We will therefore identify types of wheat which have good and stable breadmaking quality at low grain protein. Genetic analyses of the trait will provide molecular markers to assist wheat breeders while studies of underpinning mechanisms will allow new selection procedures to be used to identify germplasm and select for quality in breeding programmes. We will also work with millers and bakers to establish optimum conditions for processing of wheats with lower protein contents.