A study of olive oil emulsions with solid stabilizers

Abstract

The present piece of work has revealed that the olive oil emulsions stabilised by solids in certain respects behave in the same manner as the corresponding kerosene emulsions. Thus the degradation of the emulsion on ageing follows the normal course and there are no departures from the general behaviour of kerosene emulsions so far as the matter of lack of action of electrolyte and sensitization by some protective colloids is concerned. But these systems do present some peculiarities. For example, the emulsions of this work are less fine but more stable than the corresponding kerosene emulsions owing to the higher viscosity of the olive oil which makes the dispersion of the globules difficult but prevents them from coalescence. Bordeaux mixture when used as stabilizer exhibits the tendency of emulsifying agent antagonism and formation of multiple emulsion. The former phenomenon is more pronounced with many other emulsions which could not be investigated by size frequency analysis. This is due to the reaction in situ between the basic stabilizing bivalent and trivalent cations and oleic acid constituent of the olive oil with the production of oleates of polyvalent metals which promote reverse type of emulsions. The perplexing fact about these emulsions is that emulsifying agent antagonism is set up with certain solid agents while with other similar compounds it is evaded. As a matter of fact it varies with the mode of precipitation of the same emulsifier. So any general theoretical interpretation is to emerge only after intensive investigations.