Thermosonication for peroxidase inactivation in sugarcane juice

Abstract

To allow a widespread commercialization of sugarcane juice it is necessary to develop an effective preservation method. For that, thermosonication was evaluated as an alternative processing technology. Therefore, ultrasound (US) and conventional (CH) treatments were compared regarding peroxidase (POD) inactivation. Both treatments were performed for 25 min at 50–80 °C, with matched temperature profiles. POD inactivation kinetics were evaluated under different US parameters: pulse regime, US application time and power intensity. After treatments, sugarcane juice was monitored for 32 days under refrigerated storage to verify juice quality. Results showed that POD inactivation followed Weibull model for US and CH treatments at 70, 75 and 80 °C. At 70 and 75 °C, US lead to faster POD inactivation when compared to CH. The use of 20s on/10s off pulse regime, US application for 25 min and 75% power intensity were the best conditions for enzyme inactivation (77.3%). During refrigerated storage, POD regeneration, phenolic compounds degradation nor sedimentation were observed in the juice treated by US. For CH, on the other hand, sedimentation and lower phenolic compounds were observed. Overall, US is a potential technology for sugarcane juice enzymatic inactivation with reduced processing times and/or temperatures, leading to a better quality juice.