Physical properties of oleogels fabricated by the combination of
diacylglycerols and monoacylglycerols
Abstract
Oleogelation is an efficient way to structure oil and reduce saturated
fatty acids of lipid products. Multi-component gels are of particularly
interest attributed to the ability to tune gel properties by alteration
of the component proportions. In this study, monoacylglycerol (MAG) and
diacylglycerol (DAG) are used as gelator mixture and the influence of
the ratio of these two crystalline particles on the characteristics of
oleogels was investigated. The crystallization and melting behavior,
solid fat content (SFC), crystal morphology, polymorphism and mechanical
properties of the oleogels were characterized. The oleogels with higher
gelator level displayed higher oil binding ability and shorter crystal
formation time. The oleogels with higher MAG ratio exhibited more
blade-like crystals, and the mixed oleogels with MAG: DAG of 3:7 and 5:5
showed altered crystal morphology with finer crystal size and reduced
crystallization enthalpies possibly due to the increased nucleation
seeds promoted by MAG. The oleogels with high MAG level showed lower
equilibrium SFC during isothermal crystallization but faster
crystallization rate, higher hardness and elasticity. Therefore, by
changing the ratio of DAG with MAG, the crystallization profile and
rheological properties of oleogels can be tailored and used as
traditional solid fat substitutes in lipid-based products.