Preparo e caracterização de oleogéis com diferentes misturas de ceras naturais e aplicação em gelados comestíveis

Abstract

Through oleogelation it is possible to produce lipids with different fatty acid profiles to be applied in foods as a fat substitute with higher levels of saturated and trans fatty acids. The characteristics of an oleogel can be modulated according to the type, amount and combination of oleogelators used in its composition. Thus, two studies were carried out. The first aimed to produce oleogels with the oleogelators beeswax (BEE), carnauba wax (CAR) and candelilla wax (CAN), and their binary and ternary mixture in canola oil. These oleogels were characterized according to their physical and chemical properties to be compared with commercially used fats: hydrogenated fat, margarine and cocoa butter. The oleogels were produced with concentrations of 0.5, 1, 2, 3, 4, 6, 8 and 10% of oleogelators in canola oil (m/m). For each concentration, the oleogelators BEE:CAR:CAN in oil were combined in 10 treatments: 1:0:0, 0:1:0, 0:0:1, 1/3:2/3:0, 2/ 3:1/3:0, 1/3:0:2/3, 2/3:0:1/3, 0:2/3:1/3, 0:1/3:2/3, and 1 /3:1/3:1/3, and characterized by texture analysis, oxidative rancidity, phase diagram, differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). It was possible to structure the oil with smaller amounts of oleogelators when the oleogelators were used in combination. Using 4% wax it was possible to obtain melting temperature, firmness and oxidative stability similar to commercially used fats (margarine, hydrogenated fat and cocoa butter). The concentration of 6% of separated waxes showed the same melting temperature as 8 to 10% of separated waxes. The combination of the three waxes above 6% lowered the melting temperature of the oleogels. Oleogels produced with the three mixed waxes showed the oxidative stability two times higher than the oleogels prepared with one waxe. In the second experiment, the feasibility of producing ice creams with oleogels as milk fat substitute was assessed. The ice creams were evaluated using physical, chemical and microstructural analyses. The ice creams were produced with oleogels containing 10% BEE, or CAR, or CAN in canola oil (m/m), and a treatment with 10% of the combination of the three waxes in equal parts (1/3:1/3:1/3), totaling 4 treatments of ice cream samples produced with oleogels. A control ice cream with 10% dairy fat and one containing only 10% canola oil were also produced. Ice creams were evaluated by overrun, melt resistance, fatty acid profile, ice crystal size, fat globule size and viscosity. The ice creams with oleogels had lower amounts of saturated fatty acids than the samples produced with milk fat, and the absence of trans fatty acids. The ice cream produced with carnauba wax presented physical, chemical and microstructural characteristics more similar to the ice cream produced with dairy fat. It was concluded that the use of oleogels is a viable and healthy alternative as a substitute for dairy fat in ice cream.