Development of Physically Modified Hydrocolloids and Starches for Enhanced Salt Perception

An understanding of how food behaves in the body is obviously important. There is a physical dimension to this, in addition to nutritional and biochemical factors. Central to the work proposed in this grant is the idea that foods can mix with saliva and other water based fluids to different levels of efficiency and this impacts on how the food tastes and behaves when eaten. It is has been demonstrated that saltiness is perceived as being higher from starch thickened foods when compared to foods thickened with other materials, even though the viscosity and level of salt are the same. The reason for this is that in the starch system much of the starch remains in a particulate form, while the other materials form solutions that are then hard to mix. In the mouth, sodium that remains in the food and cannot reach the taste receptors on the tongue will not be perceived as salty. Therefore ingredients that can be added to foods that give excellent mixing quality, and hence allow the best perception of flavour, are required. A major part of the project will concentrate on the development of new particulate thickening systems using hydrocolloids and starches (already common ingredients in foods) using physical technologies that use energy sources efficiently and have low wastage. Work at Nottingham partly through a Bridge LINK project, on which this full project is based, has demonstrated the feasibility of developing new particulate ingredients from hydrocolloids such as xanthan gum. Physically modified starch that maintain particulate structures in a similar way to chemically crosslinked starches are already available, but the project will use a new approaches to produce improved ingredients of this type. The project will use a combination of sensory evaluation and instrumental techniques to develop criteria to predict salt perception and mouthfeel. In addition, a limited amount of work will be performed to confirm that the mixing hypothesis is relevant to behaviour in the stomach. To deliver this programme will require a team of companies and academics working together to further develop and then exploit the understanding partly result from a Bridge LINK project. Industrial partners in the team will supply a detailed knowledge of both suitable starting ingredients for the processing technologies and foods that will benefit from new ingredients that would allow salt levels to be reduced whilst maintaining the same flavour. There is also a requirement for expertise and specialist equipment for extrusion processing and thermal analysis, which will be supplied by industry and management from staff that are free of the major teaching and administrative pressures of a successful applied science department. Hence, the programme will have five companies plus an academic partner in a consortium to deliver the work and who can translate the findings into 'better for you' food products without loss of quality.