The degradation kinetics of ascorbic acid was determined in orange-carrot juice treated by PEF in order to establish its shelf life. Different electric field intensities (25, 30, 35, and 40 kV/cm) and different treatment times (from 30 to 340 mu s) were studied. The ascorbic acid degradation rate (k) obtained was -0.009 +/- 0.0008 mu s(-1), -0.0140 +/- 0.0009 mu s(-1), -0.0220 +/- 0.0023 mu s(-1) and -0.0187 +/- 0.0049 mu s(-1) for fields of 25, 30, 35, and 40 kV/cm, respectively. The treatment selected was 25 kV/cm. The shelf life of the orange-carrot juice treated by pulses at 25 kV/cm for two times (280 mu s and 330 mu s) was compared with a heat-treated juice (98 degrees C 21 s) kept in refrigerated storage at 2 and 10 degrees C. The remaining concentration of ascorbic acid in the pasteurized orange-carrot juice was 83%, whereas in the PEF-treated juice it was 90%. The ascorbic acid degradation rate in the juice stored at 2 degrees C was less than in the juice stored at 10 degrees C, and in the pasteurized juice it was greater. PEF treatment at 25 kV/cm for 280-330 mu s extended the half-life of the juice stored at 2 degrees C to 50 days. (c) 2005 Elsevier Ltd. All rights reserved.