Nestle uses physics to explain complex food interactions
developed a model which could help explain the texture as well the
transport of flavours and nutrients in foods.
"This discovery allows us to grasp complex food systems, providing new food science insights for enhancing the physical and functional attributes of food such as flavour, texture and nutrient delivery," said Professor Raffaele Mezzenga, Nestlé Research Center scientist. The interaction of lipids and water is a vital element of the physics of food structure, and unravelling the mechanism of interactions between lipid and water molecules could help scientists create foods with optimal stability and delivery of nutrients, active ingredients, flavours and aromas. Complex foods, which not only have to please your taste, but also accomplish a specific "healthy" function, are normally made up of a large number of components, such as protein, vitamins, and carbohydrates which make challenging their structural optimisation. By having a physically inspired approach, such as that described in Physical Review Letters, one could assemble these components into nicely structured and stable foods. The need of functional foods comes from nutritional aspects that are not directly related to the structure of the food. However, in order to release these functionalities in the body in a suitable way, the structure of the food becomes a key parameter. The authors, led by Won bo Lee, a chemical engineering graduate student from UC Santa Barbara, presented a thermodynamic model to describe the phase sequences observed in aqueous solutions of lipids, like mono-olein. Lee, Mezzenga and UCSB's Glenn Fredrickson wrote that various factors are responsible for the phase sequences, including competition between hydrogen bond formation, changes in head volume and interactions, lipid tail entropy, and the hydrophobic effect. A detailed mathematical model is presented in the journal using self-consistent field theory (SCFT), a quantum mechanical theory that enables the calculation of phase diagrams for the system. Prior to this, no quantitative theoretical framework had been established to fully interpret the structural changes that occur in lipid-water interfaces under varying conditions, said the researchers. A key challenge for the food scientists will be to identify how the physics-inspired theoretical approaches can be applied to foods on an industrial scale, particularly when there are such complex processing systems involved. "It was exciting for UCSB chemical engineering graduate student Won bo Lee and I to participate in this collaboration and apply our theoretical tools to solve a real-world problem in food science," said Fredrickson. The new study follows similar theoretical work by Mezzenga to help create, and faciliate, new food structures and processes. Back in 2005, the researchers reported that foams and emulsions can be made more stable by improving the stability of emulsifiers at the interface; and liquid crystalline foods can be used as carriers of specific ingredients. Moreover, optimising the design of polysaccharide matrices will improve the stability of foods against oxidation or thermal degradation (Nature Materials, Vol. 4, p. 729, 2005). Source: Physical Review Letters Volume 99, Issue 18, Pages 187801-1 to 18780-4 "Anomalous Phase Sequences in Lyotropic Liquid Crystals" Authors: W.B. Lee, R. Mezzenga, and G.H. Fredrickson
