Effect of combining ultrasound and UVC treatments for processing orange juice and mango nectar on their microbiological, physicochemical, and sensory characteristics

Abstract

The present study aims to evaluate the effect of ultrasound (US), UVC radiation, and combined US+UVC treatments on the inactivation of total aerobic mesophilic bacteria (TAMB) and mold and yeast in orange juice and mango nectar. The microbial inactivation after each treatment, physicochemical and sensory properties of treated products, and the microbial response during their storage at 4 °C for 12 days were assessed. Fresh squeezed orange juice and mango nectar were treated by US, UVC, or US+UVC treatments for 20 min at 15 °C; the initial TAMB and mold and yeast counts were determined. The combined treatment US+UVC showed a better inactivation level in TAMB, molds, and yeasts in orange juice and mango nectar, resulting in lower microbial counts at the storage end. Titrable acidity, °Brix, and pH remained unchanged, while ascorbic acid losses and color changes were observed. Additionally, the sedimentation index (SI) was analyzed during the storage of orange juice, observing that US+UVC reduced the SI and stabilized the orange juice for 12 days. For all tested conditions, mango nectar preserved its sensory properties. Industrial relevanceCombining food processing technologies such as ultrasound (US) and UVC radiation can improve the process's effectiveness. The US+UVC treatment enhanced the microbial inactivation (total aerobic mesophilic bacteria and mold and yeast) of orange juice and mango nectar, reduced the orange juice's sedimentation index during storage, and did not modify the sensory properties of mango nectar. Thus, the combined US+UVC treatment is an alternative to sustainably preserving and stabilizing orange juice and mango nectar.