Effect of microwave treatments on the quality of a smoothie

© 2018 International Society for Horticultural Science. All rights reserved. The effect of a pasteurization treatment of 90±2°C for 35 s, provided by a continuous semi-industrial microwave oven (MWP) under high power/short time, low power/long time, or conventional pasteurization (CP) on orange colored smoothies was investigated. Results showed that vitamin C and antioxidant capacity (FRAP) in CP decreased dramatically in comparison with the unheated and MWP smoothies. On the contrary, all heating treatments increased the total phenolic and lycopene contents of samples. The main novelty of this study was finding that the MWP over the CP method led to a larger mesophilic bacteria reduction and a better color retention. A lower residual enzyme (POD, PME and PG) activity was obtained under MWP, in particular by using high power/short time doses. Conclusively, the use of a continuous semi-industrial MW oven with 3,600 W for 93 s doses lead to a better quality of smoothies and enzyme activity reduction.