Color of orange juice treated by High Intensity Pulsed Electric Fields during refrigerated storage and comparison with pasteurized juice

High Intensity Pulsed Electric Field (HIPEF) is one of the nonthermal minimal processing technologies interesting for scientists and food industry as a new, alternative (preservation) process for liquid food. We have evaluated the effect on color, browning and hydroxymethylfurfural (HMF) of a pasteurized orange juice and the same orange juice treated by HIPEF, during 7 weeks stored in refrigeration at 2 degrees C and 10 degrees C. Pasteurized. orange juice presents greater yellow tendency (b*) and less red tendency (a*) than the untreated orange juice, while HIPEF orange juice presents a coloration more similar to the untreated orange juice. Color variations (Delta E) during storage are greater in orange juice pasteurized than in HIPEF treated orange juice. Non-thermal treated orange juice has less nonenzymatic browning than the pasteurized one. There is a significant increase in this parameter from the fourth week of storage in all the juices stored at 10 degrees C, while in the ones stored at 2 degrees C the browning index values are maintained during more time. There are no significant variations in the HMF content of the juices pasteurized or treated by HIPEF respect the untreated orange juice. During refrigerated storage, HMF is always below the maximum values established. (c) 2007 Elsevier Ltd. All rights reserved.