Characterization of Oleogels formulated by Saturated Monoglycerides and Saturated Fatty Acids in High Oleic Sunflower Oil

PALLA, CAMILA; GIACOMOZZI, ANABELLA; RICHARDS, SHARON; MARÍA E. CARRÍN

Ghent

Congreso; 14th Euro Fed Lipid Congress; 2016

Structuring liquid oils has become an interesting area of research in the last years, mainly due to pressures to reduce saturated fat intake and eliminate trans fats from our diets. Oleogels are among some of the most promising alternatives for replacing these types of fats. An oleogel can be defined as an oil entrapped within a thermo-reversible, three-dimensional gel network, which is formed by the addition of gelator molecules at low concentration. One of the oleogel systems characteristics is the possibility of tailoring their physical properties by changing the chemical nature of molecules used as organogelators or by modifying processing parameters. A wide number of different molecules are able to structured oils. They can be used alone or in mixtures, that in certain combinations have proven to be more effective. The aim of this work was to produce and characterize oleogels obtained from high oleic sunflower oil (HOSO) and saturated monoglycerides (MG) in combination with saturated fatty acids (SFA). Different ratios of MG:SFA (95:5, 70:30, 50:50, 30:70) in a total gelator concentration of 10.76 %wt -obtained from a previous optimization work of MG oleogels- were used to determine whether there is a synergistic effect. To this end, oleogels were evaluated for their oil-structuring potential by rheology, oil binding capacity (OBC) and microstructural analysis.The critical concentration of MG and SFA in HOSO was found to be 2%wt and 4%wt, respectively. Both elastic (G´) and viscous (G´´) moduli increased as the percentage of SFA was raised. OBC was greatly affected by structuring agent composition. The oleogel prepared with the lowest SFA content showed G´ values even higher than the ones obtained using only MG, as well as an increase in the OBC value (99.6% vs. 98.5%). Moreover, it was found that the microstructure of oleogels was modified by mixing two components that show different self-assembly behavior. In conclusion, by combining MG with SFA as the minor component, a synergistic enhancement in the properties of oleogels was observed. It is expected that the development of these systems ought to have improvements in the production of oleogels with rheological and thermo-mechanical properties similar to commercial margarine.