Effect of high voltage electric field on papain residual activity

Abstract

Non-thermal technologies are an alternative to avoid or reduce the heat use or thermal energy on food preservation products. Some examples are High Voltage Electric Field (HVEF), Pulsed Electric Field and Ultrasound, among others. On this research HVEF was applied to papain to determine if it has some effect in papain residual activity (RA). A Central Compound Design (CCD) was conducted to treat the enzyme, after that papain RA was measured by Kunitz method. The factors studied were: electric field (EF) (2.15, 5.0 and 7.85 kV/cm) and time (1, 15.5 and 30 minutes). The results were analyzed by the ANOVA test; a quadratic response surface model was obtained. The residual activity of the treated enzyme was 89.9% and 92.8%, with 1 min of treatment at EF of 2.15 and 7.85 kV/cm, respectively. The main reduction in RA (RA=47.7%) was obtained at 7.85 kV and 30 minutes. It was observed that both factors decrease the RA, and interaction was also significant. Finally, according to our results HVEF is a non-thermal technology capable to affect papain enzymatic activity and this effect could be extended into others products.