Inactivation and Regeneration Kinetics of Horseradish Peroxidase Heated at High Temperatures

Abstract

The inactivation kinetics of horseradish peroxidase (HRP) heated in capillary tubes in the range 110 to 135°C was studied. Its regeneration kinetics when stored at 4 and 25°C was also considered. As the severity of the treatment increased, the absolute value of the regeneration decreased. The storage temperature of the enzyme did not affect the percentage of maximum activity regenerable, although when this temperature was raised from 4 to 25°C the speed of regeneration increased. Kinetics of HRP inactivation determined after heating and after regeneration were compared. Both forms of the enzyme showed similar behavior with first-order inactivation kinetics, with Ea = 19.5 ± 1.0 kcal/mol and k120°C = 3.7 ± 0.2 min−1, and Ea = 18.8 ± 1.2 kcal/mol and k120°C = 3.7 ± 0.2 min−1, respectively.

Processing and quality characteristics of apple slices processed under simultaneous infrared dry-blanching and dehydration with intermittent heating

“…Instead, there was a drastic reduction in enzyme activities during the first 5 min while for longer heating times there was a pronounced change in slope and another linear reduction in enzyme activity but less inactivation. This agrees favorably with the enzyme inactivation pattern described by the biphasic model, which is also known as the 2-fraction model (Saraiva et al, 1996;Rodrigo et al, 1997). Fitting enzyme inactivation curves into the biphasic model resulted in rate constants (k Ts,Tc,H ) and decimal reduction times (D Ts,Tc,H ) for two isozymes of POD with different heat tolerance, namely the heat-labile and heat-resistant isozymes ( Table 3).…”

Efficacy of steamer jet-injection as alternative to chlorine in fresh-cut lettuce

“…This regeneration of POD activity after heat treatment was reported by some researchers in model conditions (Adams et al, 1996;Rodrigo et al, 1997).…”

Study of lipoxygenase and peroxidase as blanching indicator enzymes in peas: change of enzyme activity, ascorbic acid and chlorophylls during frozen storage

“…The regeneration of POD activity after heat treatment was reported by some researchers in model conditions (Adams, Harvey, & Dempsey, 1996;Rodrigo, Rodrigo, Alvarruiz, & Frigola, 1997), but not encountered during frozen storage of vegetables (Sheu & Chen, 1991;Barrett & Theerakulkait, 1995). In this study, no regeneration of LOX and POD activity was determined in any blanched samples during storage at À18 1C (Fig.…”