Aqueous phase structuring and rheology in food and personal care products

Condensed Matter lunchtime seminar

Aqueous phase structuring and rheology in food and personal care products

  • Event time: 2:00pm
  • Event date: 31st October 2012
  • Speaker: William J. Frith (Unilever)
  • Location: Room 2511,

Event details

Most processed food and personal care products have carefully tailored rheological properties that are critical to their processing, stability on storage, and texture when used or consumed. The desired rheology in a product is often achieved through the use of rheology modifiers that are present in the aqueous phase. Such ingredients can create structure and hence modify rheology in a wide variety of ways. For example, soluble polymers can gel, or create multiple phases with complex structure and rheology, surfactant molecules can self assemble to form worm-like micellar structures or form space filling crystalline structures, and colloidal particles or droplets can form colloidal glasses or aggregate to form particulate networks and gels. This variety of structuring mechanisms creates many opportunities and problems in the design and formulation of products, and it is essential that a good physical-chemical understanding of the behaviour of ingredients be developed in order to overcome the challenges faced by formulation scientists. This talk will discuss the formulation and rheological techniques used in aqueous phase structuring as applied to a selection of products. For instance ice-cream has an unfrozen phase comprising a cocktail of stabilisers and milk proteins that displays a complex multi-phase structure and rheology. Mayonnaise can be considered as a soft particle glass, in that it is a highly concentrated emulsion, however, the structure and rheology of the aqueous phase surrounding the oil droplets is also crucial in determining final product texture, and can require unusual approaches such as vane rheology in order to correctly asses the product properties. Soaps and shower gels are normally structured using the self-assembly of surfactant molecules, but it is important to understand the interaction of these micellar systems with other ingredients such as polymeric stabilisers that can lead to the formation of multiple phases with unexpected rheological consequences. The main conclusion that can be drawn from these examples is that understanding the physical-chemical mechanisms underlying the observed structure and rheology in products can be of great benefit to the formulation scientist and ultimately to the design and production of products. }, time={2pm

This is a weekly series of informal talks given primarily by members of the soft condensed matter and statistical mechanics groups, but is also open to members of other groups and external visitors. The aim of the series is to promote discussion and learning of various topics at a level suitable to the broad background of the group. Everyone is welcome to attend..

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