Degradation kinetics of chlorophylls and chlorophyllides
1991
Canjura, F.L. | Schwartz, S.J. | Nunes, R.V.
Thermal degradation of chlorophylls and chlorophyllides in spinach puree was studied from 100 to 145 degrees C (2-25 min) for chlorophylls and from 80 to 115 degrees C (2.5-39 min) for chlorophyllides. The derivatives formed were: pheophorbides, pyropheophorbides, pheophytins and pyropheophytins. Degradation kinetics of chlorophylls and chlorophyllides followed first-order kinetic model. Reaction rate data showed that the (a) form of both chlorophylls and chlorophyllides degraded more rapidly than the (b) form. Chlorophyllides were less stable than chlorophylls. Activation energies ranged from 15.0 to 22.8 Kcal/mol. A kinetic compensation effect was observed for both chlorophylls and chlorophyllides with an isokinetic temperature of 160.8 degrees C. The relative stability of these compounds suggests that methods to maximize chlorophyllides would not be effective for improving green color stability.
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