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

摘要

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 μmol/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. monococcum samples, the T. turgidum accessions clustered in three different groups, with low (0.12-0.91 μmol/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 μmol/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.