FIG. 2.
Effects of oxygen on formation of Maillard reaction products. Reaction conditions were as follows: tryptone (4.0 g/liter) plus d-glucose (3.0 g/liter), aerobic conditions (•); tryptone (4.0 g/liter), aerobic conditions (▪); and tryptone (4.0 g/liter) plus d-glucose (3.0 g/liter), anaerobic conditions (▴). In the case of anaerobic operation, a redox indicator (resazurin, 1.0 mg/liter) and reducing agents (240 mg of Na2S · 9H2O/liter and 30 mg of Na2S2O4/liter) were added to the reaction mixture and the flask was sparged with N2 until the solution became colorless. Dashed lines were obtained from the linear regression of experimental data. The slopes of the regression lines (from the top) were 8.5 × 10−3, 1.4 × 10−3, and 1.0 × 10−3 (h−1).