Table 1.
Physicochemical characteristics of the optimized shea butters
| Parameters | Beige shea butter | Yellow shea butter |
|---|---|---|
| Specific gravity (40 °C) | 0.87 ± 0.01b | 0.92 ± 0.01a |
| Refractive index (40 °C) | 1.454 ± 0.00a | 1.453 ± 0.00a |
| Viscosity (mPa.s) (40 °C) | 73.66 ± 0.20b | 96.00 ± 0.20a |
| Activation energy* (kJ/mol) | 46.81 | 50.43 |
| Colour (Ly) | 3.40 ± 0.01b | 3.90 ± 0.01a |
| pH (25 °C) | 06.50 ± 0.30b | 06.78 ± 0.30a |
| Acid index (mgKOH/g) | 0.280 ± 0.001a | 0.140 ± 0.001b |
| Peroxide index (mEqO2/kg) | 0.960 ± 0.001a | 1.010 ± 0.001a |
| Iodine index (gI2/100 g) | 52.64 ± 0.20b | 53.06 ± 0.20a |
Values given in table consist in means ± the standard deviation. Letters a, b resulted from ANOVA test; they must be considered line by line. Different letters (a, b) underline significant difference while the same letter (a, a) indicate no significant difference
Ea as activation energy, R as gaze constant R = 8314 × 10−3 kJ/mol/K. T represents the different temperatures at which viscosity was obtained; it varied from 308 to 338 °K
* Activation energy consists in the potential energy contained in one mole of shea butter. Here, it was determined graphically by drawing the function ln (Viscosity) = Ea/RT + Constante (y = Eax + constante) with