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

Abstract

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 °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 °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 °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.

Keywords

• hurdle technology
• native microflora
• storage life
• liquid food
• uv-c light
• minimal processing