Autoxidation in xylose/lysine model systems

The volatiles produced in xylose/lysine model systems added with an antioxi dant (alpha-tocopherol, 2,6-di-tert-butyl-4-methylphenol, or rosemary extra ct) or a free radical initiator (alpha,alpha-azobis-(isobutyronitrile), AIB N) were analyzed to investigate the effects of the presence of free radical s on the Maillard reaction. The pH was maintained constant at 4 or 6, by ad ding a base, and the data were compared by principal component analysis (PC A). The additives were more effective at pH 4 than pH 6. At pH 4, the model system added with AIBN is very well-discriminated by PCA from the models w ith the antioxidants and the reference model system, indicating that the vo latiles are sensitive to compounds that can interfere in an opposite way wi th free radical formation.