High-Intensity Ultrasound Processing of Passion Fruit Pulp: Effects on Physicochemical Properties, Microbiological Quality, Bioactive Compound Retention, and Ascorbate Oxidase Activity

This study aimed to evaluate the effects of high-intensity ultrasound (40 W/5 min), applied with and without mild heating (59 °C and 23 °C), and of pasteurization (63 °C/30 min), on the physicochemical, rheological, and microbiological parameters, as well as on ascorbate oxidase activity, total carotenoid content, phenolic compound profile, and antioxidant capacity of passion fruit (Passiflora edulis Sims.) pulps. Ultrasound processing induced changes in color (L*, a*, and b*), resulting in high ∆E values. Following ultrasound treatment, an increase in apparent viscosity at 100 s−1 was observed. Ultrasound also promoted partial inactivation of ascorbate oxidase and a significant reduction in mold and yeast counts. Moreover, the application of ultrasound without heating (US-20) promoted the retention of 55% of ascorbic acid after 63 days of storage. The condition with heating (US-60) led to an increase in catechin content in both bright red passion fruit pulp (173.96%) and yellow passion fruit pulp (5.89%), demonstrating a balance between the retention of bioactive compounds, microbial inactivation, and reduction in ascorbate oxidase activity. Therefore, these results highlight ultrasound as a non-thermal and sustainable technology capable of extending shelf life, maximizing the preservation of bioactive compounds, and enhancing the functional properties of fruit pulps.