This study investigated the influence of temperature on the color development of melanoidins formed from a single combination of glucose with amino acid. The selected amino acid, commonly found in apple juice and highly reactive in the Maillard reaction, were asparagine (Asn), aspartic acid (Asp) and glutamic acid (Glu). For this, the color development was evaluated by measuring browning at 420 nm and color measurements by spectrophotometry and colorimetry methods. The effect of temperature on the color intensity, the absorption of melanoidins were also measured at different wavelengths (280, 325, 405). The value of melanoidins formed from all model systems was located on a dominant wavelength of 325 nm, the ultra violet zone of the diagram. A first-order kinetic model was applied to L* and the evolution of color difference ΔE*. In addition, a*, b* values, significantly differences were...

This study investigated the influence of temperature on the color development of melanoidins formed from a single combination of glucose with amino acid. The selected amino acid, commonly found in apple juice and highly reactive in the Maillard reaction, were asparagine (Asn), aspartic acid (Asp) and glutamic acid (Glu). For this, the color development was evaluated by measuring browning at 420 nm and color measurements by spectrophotometry and colorimetry methods. The effect of temperature on the color intensity, the absorption of melanoidins were also measured at different wavelengths (280, 325, 405). The value of melanoidins formed from all model systems was located on a dominant wavelength of 325 nm, the ultra violet zone of the diagram. A first-order kinetic model was applied to L* and the evolution of color difference ΔE*. In addition, a*, b* values, significantly differences were...

In this work a study of effect of high temperature treatments (70, 80, 90 and 95oC) on color evolution in clarified lemon juices (10, 20, 35, 50 and 64.6oBrix) has been carried out. The evolution of the color with the treatment time has been continued measuring the absorbance at 420 nm (A420) and the parameters CIELab (L*, a* and b*) and color increment E *. The increase of A420 and of the decrease of the brightness L * with the time of treatment it has been observed that they are fitted to a zero order kinetic, what has allowed to obtain the corresponding ones constant kinetic of color deterioration. The evolution of E* has been described by a kinetic model in two steps. The effect of the temperature on these kinetic constants can be quantified by means of the Arrhenius equation, what allows obtaining the corresponding values of activation energy. For the A420 and L* activation en...

In this work a study of effect of high temperature treatments (70, 80, 90 and 95oC) on color evolution in clarified lemon juices (10, 20, 35, 50 and 64.6oBrix) has been carried out. The evolution of the color with the treatment time has been continued measuring the absorbance at 420 nm (A420) and the parameters CIELab (L*, a* and b*) and color increment E *. The increase of A420 and of the decrease of the brightness L * with the time of treatment it has been observed that they are fitted to a zero order kinetic, what has allowed to obtain the corresponding ones constant kinetic of color deterioration. The evolution of E* has been described by a kinetic model in two steps. The effect of the temperature on these kinetic constants can be quantified by means of the Arrhenius equation, what allows obtaining the corresponding values of activation energy. For the A420 and L* activation en...