The application of HIPEF processing (35 kV/cm for 1727 us using bipolar pulses of 4-mu s at 188 Hz) on watermelon juice was evaluated as an alternative to conventional heat treatments (90 degrees C for 30 s or 90 s) in order to achieve better preservation of watermelon aroma compounds for 56 days of storage at 4 degrees C. HIPEF processing not only induced a rise (roughly 20%) in the concentrations of hexanal, (E)-2-nonenal, nonanal, 6-methyl-5-hepten-2-one and geranylacetone but also achieved less reductions on the retention of volatiles than the thermal treatment at 90 degrees C for 60 s. In contrast, the content of (Z)-6-nonenal, 1-nonanol and (Z)-3-nonen-1-ol in the untreated and processed juices remained unchanged after processing. Despite the decrease in overall flavor compounds observed during storage irrespective of the treatment applied, HIPEF-treated juices showed better flavor retention than heat-treated samples for at least 21 days of storage. Moreover, changes in aldehydes and ketones during storage of treated watermelon juices were well fitted by a model based on the Weibull distribution function. Therefore, the application of HIPEF may be appropriate to preserve the initial volatile profile of watermelon juices during storage. (C) 2010 Elsevier Ltd. All rights reserved.