pH value Sour Orange Peels Grape Fruit Peels
  Retention% Degradation% Retention% Degradation%
2 45.36 54.32 39.53 60.63
3 55.02 45.33 52.66 47.12
4 71.33 28.36 70.12 29.87
5 82.25 17.82 80.54 19.32
6 93.31 6.11 96.51 3.56
7 97.13 2.77 96.43 3.45
8 86.54 13.16 78.21 22.32
9 79.36 20.11 77.76 22.21
Table 4: The effect of pH value on the stability of carotenoids extracted from Sour orange and Grape fruit.