Lipid Systems Structured with Sorbitan Monostearate and Fully Hydrogenated Canola Oil: Crystallization Kinetics and Microstructure
Marcella Aparecida Stahl, Glazieli Marangoni de Oliveira, Renato Grimaldi, Ana Paula Badan Ribeiro, University of Campinas, Brazil
Campinas, Brazil

The increasing incidence of cardiovascular diseases in the last century originated a continuous search for risk factors related to their development, which highlighted the trans and saturated fat in processed foods. However, reducing saturated fat in lipid bases for industrial use is not feasible by conventional methods of lipid modification, as interesterification or fractionation. On the other hand, the use of structuring agents or crystallization modifiers has been indicated as a viable alternative for obtaining low sat fats compatible for use in lipid-based foods. Based on these considerations, the aim of this study was to obtain zero trans-fat bases with low levels of saturated fatty acids. Palm oil (PO) was used as a standard reference for zero trans-fat. Different percentages of canola oil (CO) were added to the PO in order to increase the concentration of unsaturated fatty acids, obtaining the following blends: 100:0, 75:25 and 50:50 PO:CO (%w/w). Fully hydrogenated canola oil (FHCO) was used as a modifier of crystallization process; and the emulsifier sorbitan monostearate (SMS) was used as structuring agent for obtaining fat bases in low content of saturated fat acids. These additives were incorporated into the PO:CO blends at a concentration of 3% (%w/w). The evaluation of the crystallization kinetics demonstrated a significant acceleration of the onset of crystallization of the structured blends compared to the initial blends, besides increasing the solid fat content at equilibrium for all the blends evaluated. The structured blends 100:0, 75:25 e 50:50 PO:CO showed induction periods of crystallization equal to 8, 6 and 6 minutes, respectively; while the corresponding original blends were characterized by induction periods of 17, 22 and 42 minutes. The microstructural parameters indicated that the incorporation of structuring agents caused reduction in crystal size and homogeneity of the crystal lattice. Lipid bases structured with FHCO and SMS, with low levels of saturated fatty acids, showed suitable properties for application in various lipid-based foods.