Development of a potentiometric method to measure the resistance to oxidation of white wines and the antioxidant power of their constituents.
This work describes a new potentiometric method to evaluate the resistance to oxidation of white wines. Reduction and oxidation titrations were made, and coefficient of variation obtained were 10.87 and 2.65%, respectively. The antioxidant powers of ascorbic acid (Aas) and sulfur dioxide (SO(2)) were evaluated by this method, SO(2) proving to be much less active in this respect than ascorbic acid. The two agents did not demonstrate any antioxidant synergy. A relationship between oxygen present and ascorbic acid was found by the proposed method (1 mmol of O(2) <--> 0.84 mmol of Aas). This method enables the distinction of different wines on the basis of their resistance to oxidation.
Oliveira
Carla M
CM
Escola Superior de Biotecnologia, Universidade Católica Portuguesa, R. Dr. António Bernardino de Almeida, 4200-072 Porto, Portugal.
Silva Ferreira
António C
AC
Guedes De Pinho
Paula
P
Hogg
Timothy A
TA
D000704:Analysis of Variance; D000975:Antioxidants / Q000032:analysis*; D001205:Ascorbic Acid / Q000032:analysis / Q000494:pharmacology; D004357:Drug Synergism; D010084:Oxidation-Reduction; D010100:Oxygen / Q000032:analysis; D011199:Potentiometry / Q000379:methods*; D013458:Sulfur Dioxide / Q000032:analysis / Q000494:pharmacology; D014920:Wine / Q000032:analysis*
D000975:Antioxidants; D013458:Sulfur Dioxide; D001205:Ascorbic Acid; D010100:Oxygen