INFLUENCE OF PROCESSING VARIABLES ON THE RHEOLOGICAL AND TEXTURAL PROPERTIES OF LUPIN PROTEIN-STABILIZED EMULSIONS

This paper deals with the influence that the agitation speed and emuls ification time exert on the droplet size distribution and some rheolog ical and textural parameters of the final product. With this aim, oil- in-water emulsions were prepared in a rotor-stator turbine under diffe rent processing conditions (8000-20500 rpm, 3-10 min) using a vegetabl e protein, isolated from Lupinus albus seeds, as emulsifier. Oscillato ry and steady-state measurements, as well as droplet size distribution and textural profile tests, were performed. The study was carried out according to an experimental design based on the response surface met hodology. From the experimental results it may be concluded that an in crease in the energy input during the emulsification process decreases the mean droplet diameter of the emulsion and increases the values of the rheological and textural parameters, although the evolution of th ese properties cannot be explained only by the modification of the dro plet size distribution.