ADSORPTION BEHAVIOR OF WHEY PROTEINS MEASURED BY 2 DIFFERENT METHODS

The adsorption behaviour of the commercially available whey protein is olate, PROTARMOR, at the air-water and oil-water interface has been in vestigated by two different methods. The adsorption rate at a constant interface area ('isochorous mode') as a function of time was measured by a method using a 'bursting membrane' device. After 10 min the slop e of increase in film pressure reaches higher values at the air-water surface compared to adsorption at the oil-water interface. The slope o f increase in film pressure at a constant interfacial area is strongly dependent on the protein concentration in the aqueous phase. For pres sure-area curves ('isothermal mode') a rectangular Teflon trough was u sed with the surface layer being compressed by moving a Teflon barrier . From these measurements it can be concluded that the adsorption of P rotarmor at the the air-water surface is reproducible with this method . There is evidence that the adsorption of this protein mixture at the air-water surface is reversible. (C) 1998 Elsevier Science Ltd. All r ights reserved.