Table 4.
Kinetic Parameters of the Degradation of Folic Acid and Iodine in DFS* and TFS.
| Salt samples | Zero order | First order | ||||||
|---|---|---|---|---|---|---|---|---|
| k (g/ml. month-) | Activation Energy (kJ/mole) |
k (10–2 month-) | Activation energy (kJ/mole) | |||||
| 25 °C | 35 °C | 45 °C | 25 °C | 35 °C | 45 °C | |||
| Folic acid | ||||||||
| C | 1.8 ± 0.1 | 2.1 ± 0.1 | 2.6 ± 0.1 | 14.1 ± 0.7 | 2.0 ± 0.1 | 2.3 ± 0.1 | 3.2 ± 0.1 | 14.1 ± 0.7 |
| D | 2.7 ± 0.2 | 3.1 ± 0.1 | 3.7 ± 0.2 | 12.8 ± 0.6 | 3.2 ± 0.2 | 3.9 ± 0.1 | 4.6 ± 0.2 | 15.7 ± 0.7 |
| CA | 2.0 ± 0.1 | 3.0 ± 0.2 | 3.7 ± 0.1 | 27.6 ± 1.1 | 1.9 ± 0.1 | 3.2 ± 0.2 | 4.1 ± 0.1 | 30.1 ± 1.2 |
| DA | 2.3 ± 0.1 | 2.8 ± 0.2 | 3.4 ± 0.2 | 16.2 ± 0.9 | 2.8 ± 0.1 | 3.6 ± 0.3 | 4.6 ± 0.2 | 19.7 ± 1.1 |
| Iodine | ||||||||
| C | 0.8 ± 0 | 1.2 ± 0 | 1.6 ± 0 | 28.5 ± 0.8 | 0.8 ± 0 | 1.2 ± 0 | 1.9 ± 0.1 | 33.5 ± 0.8 |
| D | 1.4 ± 0 | 1.7 ± 0 | 2.3 ± 0.1 | 20.3 ± 0.5 | 1.4 ± 0 | 1.8 ± 0 | 2.4 ± 0.1 | 21.3 ± 0.5 |
| CA | 1.0 ± 0 | 1.5 ± 0.1 | 2.0 ± 0.1 | 26.4 ± 1.0 | 1.1 ± 0 | 1.8 ± 0.1 | 2.2 ± 0.1 | 26.3 ± 1.0 |
| DA | 1.0 ± 0 | 1.2 ± 0 | 1.5 ± 0 | 15.4 ± 0.4 | 1.1 ± 0 | 1.3 ± 0 | 1.9 ± 0.1 | 16.4 ± 0.4 |
The C and D salt (DFS*) are fortified by spraying folic acid and iodine solution on salt. They differ in folic acid concentration; the C salt had 12.5 ppm of folic acid + 50 ppm iodine, while the D salt had 25 ppm folic acid + 50 ppm iodine. The CA and DA salt samples had iron at 1000 ppm and their corresponding concentration of folic acid and iodine concentrations.