Optimization of thermal blanching and the effect of Golpar essential oil on peroxidase enzyme activity of celery by response surface methodology

Proxidase enzyme is one of the most important enzymes in plant tissues which can bind to hydrogen peroxide and produce an activated complex, therefore inactivation of the enzyme may increase the shelf life of raw and un-blanched frozen vegetables. Nowadays, consumer's trend has been oriented to use fresh products or foods prepared by little process, therefore producers are interested the ways to increase shelf life by use of alternative methods. In this study the effect of natural essential oil (Golpar oil) and thermal blanching on peroxidase enzyme activity were investigated and optimization of peroxidase enzyme inactivation was performed using response surface methodology. Results showed that peroxidase activity of celery extracts was affected by the essential oil and its activity was reduced. Optimum conditions for non-thermal inactivation of proxidase enzyme under effect of golpar oil were included Golpar concentration 50 ppm, the time of enzyme activity 60 second and enzyme activity (absorption) 0.467599. Optimum conditions for thermal inactivation of peroxidase enzyme of celery were included blanching temperature 90 oC, blanching time 5 minutes, the time of enzyme activity 20 second and enzyme activity (absorption) 0.0452815.