Effect of different propylene glycol esters on fat physical properties

The effect of different propylene glycol monoesters on the thermodynamic properties and crystallization characteristics of lipids was studied.Propylene glycol stearic acid ester,propylene glycol lauric oleic acid ester and propylene glycol lauric acid ester were the three type of most widely used propylene glycol ester emulsifiers in current market.Results of DSC showed that the three propylene glycol esters exerted significant influence on the thermodynamic properties of grease.With increasing amount of esters added,both melting point and enthalpy of mixed lipids were reduced.Especially when the propylene glycol ester of stearic acid was added,the trend was particularly significant.Though analysing crystal morphology structural of the three propylene glycol esters grease by X-ray diffraction,it was found that propylene glycol esters with fatty acids had negative influence on crystal transformation of lipids,i.e.increasing addition of propylene glycol esters led to stronger inhibiting degree.Effects of stearic acid monoester were the most evident.Fat with addition of 50% proportion could maintain stable α phase.However,propylene glycol acid ester with unsaturated fatty had few influence on crystal transformation.