Production of vegetable oil in milk emulsions using membrane emulsification

Abstract

The production of emulsions using milk as the continuous phase has a number of applications of interest from the food industry's point of view. In addition, producing an emulsion with a narrow drop size distribution is interesting since their increased stability could avoid Oswald ripening and creaming. Membrane emulsification is a novel technique which helps to obtain a narrower distribution compared to other emulsification techniques such as homogenizers or ultrasound. Moreover the use of membrane emulsification may reduce the energy cost. The food industry is interested in reducing the use of food additives, both to save money and increase consumer acceptance. Therefore the aim of this work was to investigate the use of the intrinsic emulsifying capacity of milk proteins to act as stabilizers for oil droplets produced by membrane emulsification. Using tubular SPG membrane (4.8 μm pore diameter) in recirculation mode, at dispersed phase fluxes of either 5 L/hm 2 or 50 L/hm 2, a stable final emulsion of 30% w/w oil was obtained. The fat globule size distribution was more bimodal at higher oil concentrations and at the higher flux.