Decrease of HT chlorogenic acid content in sunflower meal using an enzyme preparation secreted by the white-rot fungus Trametes versicolor

Abstract

This project describes the enzymatic degradation of chlorogenic acid (CGA) in a model system with pure CGA and in a sunflower meal (SFM) system. The effects of several parameters, such as pH, temperature, and substrate, enzyme and sunflower meal concentrations, on the decrease of the CGA concentration were studied. The optimum pH was found to be 4.3 for the model system and 3.4 for the SFM system; the difference in pH was due to the buffering capacity of the meal in the SFM system. The optimum temperature was 45°C for both systems. There is a linear relationship between the enzyme concentration and the initial reaction rate for low enzyme concentrations. That linearity disappears when the enzyme concentration was higher than 1 nkat/mL and 2.2 nkat/mL for the model and SFM systems, respectively. Regarding the effect of the substrate concentration, a saturation with substrate was noticed when its concentration was 0.13 mM. (Abstract shortened by UMI.)