## 3 Results and Discussion
The ZP of CG purified (Table 1) showed a negative charge, \(-\)2.98 mV, and the \(\alpha\)-Toc has reported in the literature a positive charge (+13.1 mV). The obtained ZP for the particles can suggest an electrostatic interaction between them since opposite surface charges are one of the main binding forces between the compounds when mixed to form particles or complexes [43]. After obtaining the particles with both components, the complex presented ZP in the range of \(-\)23.9 to \(-\)25.8, emphasizing the negative charge presented by CG and suggesting the gum in the outer layer. These results mean a homogeneous dispersion with moderate stability of the particles [15]. Although the particles are stable, they are influenced by the concentration of \(\alpha\)-Toc in their size. Using 6400\(\times\)\(g\) in centrifugation, we have seen that cashew gum nanoparticles were separated enough to allow sampling an aliquot of supernatant for the measurements of unloaded oil. The \(\alpha\)-Toc encapsulation efficiency was above 99% in all formulations (Table 1), in contrast with a previous study with CG for oil encapsulation, in which the maximum encapsulation efficiency was 93% [17]. Inversely proportional to E.E., the L.C. tends to increase when the active incorporated concentration gets higher. This behavior can be observed in Table 1, where CGNPs+50 presented 32.92 \(\pm\) 0.365% of \(\alpha\)-Toc in the final formulation, and the others CGNPs+25 19.76 \(\pm\) 0.080% and CGNPs+10 8.91 \(\pm\) 0.089%. The solution stability is influenced by numerous factors, including the adsorption of surface-active molecules and the use of surfactant in the synthesis of particle aggregation, the chemical composition of the components, and also the premature release of the active principle [8]. Therefore, the stability of the case was analyzed by DLS immediately after synthesis and during the following 4 weeks (Figure 3). The particles showed excellent stability when analyzed macroscopically, and did not present visual sedimentation, flocculation, or even a creamy appearance during the study period. The visual analysis corroborates with DLS results, which show that there was no significant variation among the evaluated points, between the weeks, observing the samples individually. On the other hand, the variation in size by the number of their populations maintained from the 2 nd week of storage the CGNPs+25 and CGNPs+50 with no significant difference between them, unlike CGNPs+10. The CGNPs+25 showed a higher standard deviation for size and PDI over the weeks of storage; however, it was not a significant variation. The CGNPs+10 showed the smallest variation in size, number, and PDI among all particles, over the entire period evaluated. These results confirm the ZP initially presented by the particles. The ZP of the particles did not show significant variation over time, presenting negative zeta, which results in lower cellular absorption and also low cell cytotoxicity, and in the range of \(-\)20 mV, which is considered an acceptable stability range. The same stability can be seen in a study with \(\alpha\)-Toc encapsulated in niosomes that presented ZP in the same mV range [44]. The thermal analysis aims to evaluate chemical reactions, physical properties, and structural changes that may occur due to the temperature imposed on the material. These temperatures, evaluated by TGA/DTG, are displayed in curves in Figure 4A. The first stage presented by CGNPs was observed up to 125 \({}^{\circ}\) C and is related to the moisture content evaporation. This stage resulted in a mass variation of \(\Delta\)m\({}_{1}\) = 2.69% and T\({}_{\text{peak DTG}}\) = 53.18 \({}^{\circ}\)C; \(\Delta\)m\({}_{1}\) = 2.43% and T\({}_{\text{peak DTG}}\) = 52.92 \({}^{\circ}\)C; and \(\Delta\)m\({}_{1}\) = 2.34% and T\({}_{\text{peak DTG}}\) = 56.98 \({}^{\circ}\)C for CGNPs+10, CGNPs+25 and CGNPs+50, respectively.