Effect of monoglyceride content on emulsion stability and rheology of mayonnaise.

The aim of the study was to determine the effects of monoglyceride content on emulsion stability and rheology of mayonnaise. For this purpose, mono (MG) and diglycerides (DG) were produced by transesterification of refined olive oil with elevating glycerol contents from 25 to 100 g and reaction times from 25 to 40 min. Maximum MG-DG yield was obtained when the reaction was performed for 40 min using 75 or 100 g of glycerol. Under these conditions, 90% of triglycerides (TG) were converted to 40% MG and 50% DG. Using a molecular distillation unit, MG was separated from the transesterification reaction mixture and purified up to 98%. Emulsifiers were then prepared by introducing distilled MG into the transesterification reaction mixture in order to increase the MG concentration from 40 to 98%, for enabling the utilization of them in mayonnaise production. The mayonnaise incorporated with 98% MG showed the highest stability and reduction in the MG concentration in the emulsifier mixture decreased the emulsion stability. Rheological measurements indicated that the control sample without emulsifier had the highest viscosity and shear stress values. The increment of the MG concentration in the emulsifier mixtures resulted in only small differences on the rheological properties of mayonnaise.