Vitamin C Research Today is a free monthly online journal that collates and summarizes the latest research about Vitamin C, including details on benefits, dosage, supplements, information.

Stability of copigmented anthocyanins and ascorbic acid in a grape juice model system.

Brenes CH, Del Pozo-Insfran D, Talcott ST

Department of Food Technology, ITESM-Campus Monterrey, E. Garza Sada 2501 Sur, C.P. 64849, Monterrey, N.L., Mexico. chbrenes@itesm.mx

The stability of red grape anthocyanins (Vitis vinifera) was evaluated in a model juice system during normal (25 degrees C) and accelerated storage (35 degrees C) in the presence of ascorbic acid. Rosemary polyphenolic cofactors (0, 0.2, and 0.4% v/v) were evaluated as anthocyanin stabilizing agents. Cofactor addition resulted in concentration-dependent hyperchromic (up to 178%) and bathochromic (up to 23 nm) shifts, indicating a more intense red coloration of the models. Anthocyanin and ascorbic acid degradation followed first-order kinetics during storage. Results showed that copigmented treatments underwent a lower conversion of L-ascorbic acid into dehydroascorbic acid during storage when compared to the control, favorably impacting the vitamin retention of these models. Copigmentation did not affect anthocyanin degradation in the absence of ascorbic acid but in its presence aided to retain a higher anthocyanin content than the control. This study indicated that the addition of anthocyanin cofactors could be used to reduce the pigment and vitamin degradation while masking detrimental color changes in anthocyanin containing products.

Published 5 January 2005 in J Agric Food Chem, 53(1): 49-56.
Full-text of this article is available online (may require subscription).

© 2004-2008 Vitamin C Research Today. All Rights Reserved.