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Journal of agricultural and food chemistry, 2005-06, Vol.53 (12), p.4938-4945
Ort / Verlag
Washington, DC: American Chemical Society
Erscheinungsjahr
2005
Link zum Volltext
Quelle
MEDLINE
Beschreibungen/Notizen
The aim of this study was to investigate the effect of kilning and roasting temperatures on antioxidant activity of malt model systems prepared from combinations of glucose, proline, and ferulic acid. Model systems (initial a w = 0.09, 6% moisture) were heated at 60 °C for up to 24 h, at 90 °C for up to 120 min, and at 220 °C for up to 15 min. The antioxidant activity of the glucose−proline−ferulic acid model system increased significantly on heating at 60 °C for 24 h or at 90 °C for 120 min. In contrast, the glucose−proline, ferulic acid−glucose, and ferulic acid−proline systems presented either nonsignificantly increased or unchanged antioxidant activity. The antioxidant activity of both the glucose−proline−ferulic acid and glucose−proline model systems increased significantly after heating at 220 °C for 10 min, followed by a significant decrease at 15 min. The data suggest that (1) at 60 °C, ferulic acid reacts with Maillard reaction products, resulting in a significant increase in antioxidant activity; (2) at 90 °C, the antioxidant activity of the glucose−proline−ferulic system comes from both ferulic acid and Maillard reaction products; and (3) at 220 °C, the major contributors to antioxidant activity in glucose−proline−ferulic acid and glucose−proline systems are glucose−proline reaction products. Keywords: Antioxidant activity; ferulic acid; ABTS•+ assay; ORAC assay; capillary electrophoresis; Maillard reaction