The effects of Maillard reaction products on apple and potato polyphenoloxidase and their antioxidant activity
Omar M. Atrooz*
Department of Biological Sciences, Mu’tah University, P.O. Box (7), Mu’tah, Jordan
(Received 12 March 2006; Accepted in revised form 09 October 2006)
The effects of Maillard reaction products (MRPs) on apple and potato polyphenol oxidase (PPO) were estimated spectrophotometrically. Model systems of glucose and amino acids [lysine (lys), tyrosine (tyr), proline (pro), cysteine (cys), glumatic acid (glu), aspartic acid (asp), and histidine (his)] were heated at 90 C for 3 h. The MRPs showed inhibitory effects on PPO extracted from apple and potato. These effects depend on the type of MRP and origin of PPO. The antioxidant activity of MRPs was evaluated. It was found that MRPs exhibit different free radical scavenging activity and these effects were significant. The colour intensity of MRPs was estimated. Browning was not directly related to the antioxidant activity.
Keywords: Antioxidant activity, colour intensity, enzyme inhibition, Maillard reaction product.
International Journal of Food Science & Technology
Volume 43, Issue 3, pages 490–494, March 2008