Abstract

DI SCIPIO, SABRINA; ESCALONA, YESSICA; QUIJADA, KARINA  and  MILLAN, FÉLIX. Study of the mixing of concentrated oil in water emulsions applying the surface response methodology. Rev. Fac. Ing. UCV [online]. 2008, vol.23, n.3, pp.53-64. ISSN 0798-4065.

In the Food Industry, highly-concentrated disperse phase emulsions (> 75%) are frequently produced, considering physicochemical and compositional parameters, and the mixing conditions. Most of the research related to the mixing of disperse systems has studied diluted systems without surfactants. The present work deals with the preparation of highly-concentrated corn oil in water emulsions with ethoxylated non ionic surfactant. The experimental method was based on factorial design 2³ with central and axial points, where impeller rotational speed, time agitation and, oil: water ratio were varied. The influence of those variables on volume and surface area mean drop diameter of emulsions, d₄₃ and d₃₂, respectively, was evaluated. Through the analysis of variance of experimental space, eliminating the non-significant effects, it was determined that d₄₃ can be predicted almost by 99% by a quadratic model, but this model, by itself, can not explain the d₃₂ whole extension response surface, because the lack of fit is considerable; however the quadratic model can be used to analyze the influence of the variables. A cubic fit was developed for the d₃₂, this model presented confused terms that do not permit the determination of a final relationship between pure and crossed variables, but allows the exploration of the complete d surface response, because it represents better the experimental variability without lack of fit. The model’s assumptions normality, independence, and homocedasticity were satisfied.

Keywords : Emulsion; Sauter diameter (d₃₂); Volume mean diameter (d₄₃); Response surface methodology.