Table 1.
Results of preliminary stability tests of nanoemulsions with and without Opuntia ficus-indica (L.) Mill extract.
| Parameters | FX | FXE |
|---|---|---|
| After 24 h | ||
| Centrifugation | N | N |
| pH value | 5.62 ± 0.04 | 5.53 ± 0.02 |
| Electrical conductivity (µS/cm) | 676.0 ± 3.0 * | 689.4 ± 4.7 * |
| Droplet size (nm) | 142.6 ± 2.3 * | 139.1 ± 2.8 * |
| PDI | 0.26 ± 0.01 | 0.23 ± 0.01 |
| Zeta potential (mV) | −38.10 ± 1.69 * | −42.98 ± 0.88 |
| After TS | ||
| pH value | N/A | N/A |
| Electrical conductivity (µS/cm) | N/A | N/A |
| Droplet size (nm) | N/A | N/A |
| PDI | N/A | N/A |
| Zeta potential (mV) | N/A | N/A |
| After FDC | ||
| pH value | 5.55 ± 0.05 | 5.49 ± 0.01 |
| Electrical conductivity (µS/cm) | 457.7 ± 33.6 * | 510.7 ± 3.1 * |
| Droplet size (nm) | 160.6 ± 3.3 * | 148.8 ± 1.6 * |
| PDI | 0.21 ± 0.02 | 0.26 ± 0.01 |
| Zeta potential (mV) | −47.01 ± 1.64 * | −42.58 ± 0.99 |
Notes: FDC = Freeze-Defrost Cycles; TS = Thermal Stress; N = Normal; N/A = Not evaluated, PDI = Polidispersion Index; FX = Sample containing 0.5% Xanthan Gum; FXE = Sample containing to 0.5% Xantham Gum and 1% Opuntia ficus-indica extract. * p < 0.05 compared to the initial time.