IMPACT OF THE DEACIDIFICATION PROCESS ON THE QUALITY, LIPID PROFILE, AND CAROTENOID RETENTION IN PEQUI (CARYOCAR BRASILIENSE) OIL

Pequi (Caryocar brasiliense) oil is an important source of bioactive compounds, notably its high carotenoid content. However, in its crude form, it can present high acidity due to the presence of free fatty acids (FFA), making the deacidification step necessary to remove these acids and enable its food use. However, this process can cause a reduction of bioactive compounds in vegetable oils. Thus, this study aimed to evaluate the impact of ethanolic deacidification compared to conventional alkaline neutralization on carotenoid retention, acylglycerol distribution, color, and thermal behavior of pequi oil. Samples of crude oil, ethanolic-deacidified (4 washing stages with 90% ethanol, 1:1 w/w ratio, at 25 °C), and alkaline-deacidified (with 18 °Bé NaOH solution) were evaluated for titratable acidity, acylglycerol composition (HPSEC – high-performance size-exclusion chromatography), total carotenoids (spectrophotometry), color (Lovibond colorimeter), and thermal properties (DSC). Both processes efficiently reduced the initial acidity of 1.35% in the crude oil to suitable levels: 0.20% in ethanolic extraction and 0.28% in alkaline neutralization. HPSEC analysis demonstrated that ethanolic extraction increased the triacylglycerol (TAG) content from 94.34% to 99.10%, reducing diacylglycerols (DAG) from 3.18% to 0.51% and monoacylglycerols + FFA from 2.49% to 0.39%, which is associated with the preferential partitioning of more polar compounds into the ethanolic phase. NaOH neutralization resulted in 96.64% TAG and maintained 2.54% DAG. Regarding total carotenoid content, 164.55 mg/kg was observed in the crude oil, 147.83 mg/kg in the ethanolic route, and 168.04 mg/kg in the alkaline route. The small difference observed in the ethanolic route suggests a slight transfer of pigments to the alcoholic phase, consistent with the discrete reduction in red units in the Lovibond color (12.15 in crude, 10.10 in ethanolic refining, and 11.13 in alkaline), while keeping yellow constant (70.0). DSC thermograms indicated that neither process altered the crystallization and melting profiles of the oil, suggesting the preservation of the thermal stability of the lipid matrix. Ethanolic deacidification proved to be an efficient alternative for pequi oil refining, promoting FFA removal and purification of the lipid fraction (DAG removal) while maintaining carotenoids and thermal stability. The authors acknowledge CAPES for financial support and FEA/UNICAMP for institutional support.