Betanin, the main pigment of red beet - molecular origin of its exceptionally high free radical scavenging activity

Anna Gliszczyńska-Świgło (1) , Henryk Szymusiak (2) , Paulina Malinowska (3)

1 Faculty of Commodity Science
2 Faculty of Commodity Science
3 Faculty of Commodity Science

In the present study, the pH-dependent free radical scavenging activity of betanin in the TEAC (Trolox equivalent antioxidant capacity) assay was determined. It was found that at pH > 4 betanin is about 1.5-2-fold more active than some anthocyanins considered very good free radical scavengers as determined in the TEAC assay. The increase in the TEAC values of betanin with increasing pH is discussed in terms of its calculated phenolic OH homolytic bond dossociation energy (BDE) and ionization potential (IP). The results obtained suggest that the exceptionally high antioxidant activity of betanin is associated with increasing of its H-donation and electron-donation ability when going from cationic state to mono-, di- and tri-deprotonated states present at basic solutions.

Mots clés: Life Sciences

Anna Gliszczyńska-Świgło, Henryk Szymusiak, Paulina Malinowska. Betanin, the main pigment of red beet - molecular origin of its exceptionally high free radical scavenging activity. Food Additives and Contaminants, 2006, 23 (11), pp.1079-1087. ⟨10.1080/02652030600986032⟩. ⟨hal-00577387⟩