DEVELOPMENT AND CHARACTERIZATION OF LIPID MIXTURES OBTAINED FROM MACAÚBA OILS: CRYSTALLIZATION PROPERTIES

Macaúba is an oilseed palm native to Brazil, with high oil productivity and climate adaptability, which makes it promising for applications in the food and cosmetics industry and as an alternative source for biodiesel. Despite this potential, the use of fully hydrogenated lipid systems (hardfats) derived from its oils is still unprecedented. The objective of this work was to develop and characterize binary mixtures composed of fully hydrogenated macaúba pulp oil (OPMTH) combined with macaúba pulp oil (OPM) and almond oil (OAM). The mixtures were prepared in the proportions (%) OPMTH:OPM and OPMTH:OAM 100:0, 75:25, 50:50, 25:75 and 0:100, subjected to isothermal crystallization (25 °C) by NMR and characterized according to Campos (2005) and Ribeiro et al. (2009), and thermal analysis by differential scanning calorimetry (DSC) according to the AOCS Cj 1-94 method (2009). In the crystallization isotherms, the increase of OPMTH in the mixtures significantly increased the maximum solids content (SFCmax), in addition to reducing the induction time (tSFC) and the time to reach half of the SFCmax (t1/2SFCmax). The sample with 100% OPMTH showed the highest SFCmax (91.12%) and faster crystallization (tSFC = 2 min; t1/2SFCmax = 5.6 min), due to the greater presence of triacylglycerols (TAGs) In contrast, the 100% OAM and OPM samples did not reach 1% solids at 25 °C. The higher crystallization rates observed in the isotherms are reflected in the thermal behavior, as the increase in the OPMTH fraction in both systems shifted the crystallization events to higher temperatures and made them more intense (elevation of the onset (Ti), end (Tf), and peak (Tp) crystallization temperatures, as well as peak height (Ap)), indicating greater process intensity due to the increased solid content. The first peak, associated with the crystallization of saturated TAGs, became more pronounced with the increased concentration of hardfat. In contrast, the secondary peaks, related to more unsaturated TAGs, showed lower enthalpy (ΔH) with the addition of OPMTH. In the melting profile, both systems also showed two peaks: the first showed a reduction in Ap and ΔH with the addition of hardfat; the second, on the other hand, exhibited higher values for these parameters, with melting occurring at higher temperatures. These results demonstrate how the triacylglycerol composition directly influenced the rate and intensity of the crystallization and melting events in the lipid blends formulated from macaúba oils.