Design of complex microstructures and processes for advanced salt reduction in foods

Overall the research project will investigate the design of complex microstructures and processes for their manufacture, to achieve salt reduction in foods. The aim is, not simply to reduce salt, or replace it by use of alternative chemicals but to carefully establish salt delivery profiles that give the required perception of taste and flavour with a dramatic decrease in the 'hidden salt'. For instance have salt released in pulses in the mouth during consumption or increasing the rate of salt release during mastication etc. Such approaches will not compromise to the consumer in terms of perceived flavour, enjoyment or e-numbers. Thereby, a minimum amount of salt for good flavour will be used, leading to high quality and tasty foods with much lower salt giving the opportunity to work towards government guidelines of reducing the salt intake. Hence, the controlled delivery of salt from complex microstructures during consumption is the subject of this research. The work in Birmingham aims to design complex microstructures to modulate perception by delivering specific release profiles determined from experiments performed at the University of Nottingham. An in-vitro experimental system capable of measuring salt deposition, retention and release in the local vicinity of salt receptors mimicking in-mouth saliva flow conditions will be designed and built. In order to achieve the desired flow profile it is necessary to develop greater understanding of the key factors of how product microstructure and saliva flow affects the action of salt in the local region of salt receptors. This will be achieved using the in-vitro measurement system to study a range of well controlled complex microstructures including structured aqueous phases, structured interfacial layers, o/w, w/o and w/w emulsions and dispersions. Key control parameters to be investigated will include phase inversion, phase continuity, controlled dispersion (size distribution and volume fraction), formulation and rheology. To achieve phased release of salt, inclusion of complex microcapsules will be studied. Other technical routes to be pursued will include compartmentalization of salt using duplex particles and biopolymers. A computational model will be developed in collaboration with Unilever that would predict the deposition, retention and release of salt from structured food materials to the bio-substrate of salt receptors. Accuracy of developed models will be evaluated with experimental measurements. The validated models will be used to optimize microstructures in order to achieve truly modulated salt delivery. In the later stages of the project and once the production of real food systems has commenced the in house equipment will be used to evaluate salt release profiles