Table 4.
Results obtained at ascorbic acid determination in natural juices, soft drinks and wines* by differential pulse voltammetry and cyclic voltammetry performed at a carbon paste electrode.
| Analysed product | Ascorbic acid concentration -cyclic voltammetry (mg/100 mL juice) | Ascorbic acid concentration -cyclic voltammetry- after addition (35.2 mg AA added to 100 mL juice) | Degree of recovery (%) | Ascorbic acid concentration -differential pulse voltammetry (mg/100 mL juice) | Ascorbic acid concentration- differential pulse voltammetry- after addition (35.2 mg AA added to 100 mL juice) | Degree of recovery (%) |
|---|---|---|---|---|---|---|
| Orange juice | 39.40 | 72.52 | 98.23 | 40.68 | 75.64 | 103.62 |
| Grapefruit juice | 37.71 | 72.22 | 102.14 | 39.05 | 74.50 | 104.96 |
| Lemon juice | 52.94 | 87.07 | 101.91 | 54.74 | 87.15 | 97.04 |
| Fanta madness | 7.19 | 40.77 | 97.71 | 7.08 | 42.58 | 103.27 |
| Prigat grapefruit | 12.81 | 48.48 | 104.11 | 12.27 | 45.30 | 96.41 |
| Prigat sour cherry | 12.99 | 45.47 | 94.87 | 12.16 | 44.75 | 95.13 |
| Prigat kiwi | 15.48 | 50.73 | 103.04 | 15.17 | 49.90 | 101.51 |
| Frutia tomato | 18.63 | 52.45 | 99.07 | 19.24 | 54.27 | 102.61 |
| Wine (Recas vineyard) | 15.07 | 48.71 | 98.35 | 16.22 | 49.63 | 97.74 |
* Producers are the same as in Table 3.