Lipoxygenase activity in wholemeal flours from Triticum monococcum, Triticum turgidum and Triticum aestivum

To minimise lipid oxidation and maintain high carotenoid and tocol concentrations in wheat flours and products, fifty-seven accessions, belonging to different Triticum species (Triticum monococcum, Triticum turgidum and Triticum aestivum), were assessed for lipoxygenase activity. The highest enzymatic activity was observed in T. aestivum (8.02 +/- 0.492 mu mol/min/g DM), followed by T. turgidum (3.48 +/- 0.701) and by T. monococcum (0.45 +/- 0.072). While the lipoxygenase was consistently high amongst T. aestivum and steadily low amongst T. rnonococcum samples, the T. turgidum accessions clustered in three different groups, with low (0.12-0.91 mu mol/min/g DM), medium (3.10-4.17) and high (5.57-9.51) activity. Enzymatic activity was maximum in the pH range 5-6. LOX activity was higher in the germ (206 mu mol/min/g DM), than in the bran (13.4) or in the endosperm (3.1). The results demonstrate that the selection of genotypes with low LOX, a factor limiting oxidative degradation, is feasible. (C) 2011 Elsevier Ltd. All rights reserved.