Effect of ultraviolet-C light and mild thermal treatment on the storage life of orange juice

This study aimed to evaluate the effect of low-dosage treatment with ultraviolet-C light (19.75 J L-1 for 5 min), mild thermal treatment (40 degrees C for 5 min), or their combination on the native microflora (mesophiles and moulds plus yeast) and consumer acceptance of orange juice at the beginning and after storage (5 or 22 degrees C). Results indicated that UV-C light and mild thermal treatments reduce 0.19 +/- 0.03 and 0.25 +/- 0.02 log cycles (both kinds of microorganisms), respectively. The combination of treatments displays an additive effect against mesophiles (0.47 +/- 0.01 log) and moulds plus yeasts (0.42 +/- 0.02 log). After 9 days of storage at 5 degrees C, combined treatment did not present any microbial increases (P> 0.05), while consumer acceptance was similar (P > 0.05) to the fresh orange juice. Although several studies about the use of hurdle technology using UV-C light in orange juice have to be conducted, the results obtained in this study are promising, and they can be used for further studies.