CRUDE PALM OIL NANOPARTICLES: PREPARATION, CHARACTERIZATION AND EMULSIFYING INFLUENCE

Crude palm oil (CPO) has significant quantities of carotenoids, especially β-carotene, which has vitamin A precursor and antioxidant activity. Nevertheless, vegetable oils are unstable against storage and temperature, mainly by the autoxidation process, which makes them sensitive to oxygen and light. Considering that nanotechnology has been positive results in preservation of bioactive compounds of vegetable oils, the aim of this study is to prepare and characterize CPO nanoparticles using pectin from passion fruit (mesocarp) as encapsulant and to evaluate the effect off different emulsifiers on their characteristics. Pectin passion fruit was chosen because it is a byproduct with satisfactory characteristics to be an encapsulant. The nanoparticles were prepared through the formation of nanoemulsions, being characterized about particle size, zeta potential, polydispersity index, pH, viscosity, color, antioxidant activity and total carotenoids. The effect of three emulsifiers: tween 20, tween 80 and soy lecithin at concentrations of 1mg / mL and 2mg / mL were also evaluated. The obtained results indicates: nanoparticles diameter varying between 232.17 ± 0.84 and 318.77 ± 2.21 nm (similar values to those found in literature), a polydispersity index between 0.25 ± 0.01 and 0.39 ± 0.02 (values lowers than 0.3 indicate good homogenization) and a zeta potential between -27.57 ± 1.42 and -43.67 ± 3.16 mV (parameter that indicate stability when ≥than 30 in absolute value). All formulations showed good results of size and zeta potential, and that one with soy lecithin at the highest concentration obtained the best homogenization.The color parameters L *, a * and b * varied between 36.18 ± 0.83 and 43.05 ± 0.08, -2.36 ± 0.22 and -3.99 ± 0.03 and 10.21 ± 0.44 and 13.01 ± 0.14, respectively. The nanoparticles showed yellow tendency and it is related to influences caused by emulsifiers and its concentrations. The pH of all formulations was approximately 5 and the viscosity ranged from 2.89 ± 0.03 cP (soy lecithin 2 mg / mL) to 10.82 ± 0.15 cP (Tween 80 2 mg / mL). Carotenoids extraction for quantification was done with hexane and methanol, oven drying at 35ºC and later dilution in petroleum ether for spectrophotometer reading. There was preservation of part of the carotenoids relative to CPO in all formulations, and the amount of loss may have occurred in the pigments extraction for quantification because the extraction has many steps. It caused exposure by oxygen, which can lead to these pigments reduction.The antioxidant activity of the nanoparticles was approximately 50%, twice that found in CPO (25%), indicating that the antioxidant potential was influenced not only by the palm oil, but also by the polymer material (maybe caused by flavonoids in their composition, composts that also have antioxidant potential, but not determined in this study).The present study showed that it is possible to produce CPO nanoparticles with pectin from passion fruit as an encapsulating agent and that the emulsifiers and their concentrations can influence in color, viscosity and homogeneity parameters of the nanoparticles.