The bioactive compounds, antioxidant capacity and microbiological quality of melon juice processed by high-intensity ultrasound (HIUS) were studied. Melon juice was processed at two ultrasound intensities (27 and 52 W/cm²) for two different processing times (10 and 30 min) using two duty cycles (30 and 75%). Unprocessed juice was taken as a control. Total carotenoids and total phenolic compounds (TPC) were the bioactive compounds analyzed while the antioxidant capacity was determined by DPPH, ABTS and FRAP assays. The microbiological quality was tested by counting the aerobic and coliforms count as well as molds and yeasts. Total carotenoids increased by up to 42% while TPC decreased by 33% as a consequence of HIUS processing regarding control juice (carotenoids: 23 μg/g, TPC: 1.1 mg GAE/g), gallic acid and syringic acid being the only phenolic compounds identified. The antioxidant capacity of melon juice was enhanced by HIUS, achieving values of 45% and 20% of DPPH and ABTS inhibition, respectively, while >120 mg TE/100 g was determined by FRAP assay. Further, the microbial load of melon juice was significantly reduced by HIUS processing, coliforms and molds being the most sensitive. Thus, the HIUS could be an excellent alternative supportive the deep-processing of melon products.

Aloe mucilages of Aloe ferox (A. ferox) and Aloe vera (A. vera) were spray-dried (SD) at 150, 160 and 170 °C. Polysaccharide composition, total phenolic compounds (TPC), antioxidant capacity and functional properties (FP) were determined. A. ferox polysaccharides were comprised mainly of mannose, accounting for >70% of SD aloe mucilages; similar results were observed for A. vera. Further, an acetylated mannan with a degree of acetylation >90% was detected in A. ferox by ¹H NMR and FTIR. SD increased the TPC as well as the antioxidant capacity of A. ferox measured by both ABTS and DPPH methods, in particular by ~30%, ~28% and ~35%, respectively, whereas in A. vera, the antioxidant capacity measured by ABTS was reduced (>20%) as a consequence of SD. Further, FP, such as swelling, increased around 25% when A. ferox was spray-dried at 160 °C, while water retention and fat adsorption capacities exhibited lower values when the drying temperature increased. The occurrence of an acetylated mannan with a high degree of acetylation, together with the enhanced antioxidant capacity, suggests that SD A. ferox could be a valuable alternative raw material for the development of new functional food ingredients based on Aloe plants.

High-intensity ultrasound (HIUS) is a non-thermal processing technology with the potential to modify the functionality of plant-derived materials. This study evaluated the effect of HIUS on the techno-functional properties, rheology, phenolic profile, aloin content, and antioxidant activity of Aloe vera gel at 11, 28, and 43 W/cm² for 2.5, 5, and 7.5 min. HIUS reduced swelling capacity from 284.92 mL/g in the untreated sample by up to ~60%, while water retention capacity increased from 45.62 g/g to values close to 90 g/g. Fat adsorption capacity reached its highest value at 28 W/cm² for 5 min (~60 g/g). Rheological analysis confirmed shear-thinning behavior and a marked viscosity reduction after sonication, with zero-shear viscosity ranging from 0.055 to 0.569 Pa·s. Total phenolic content decreased from ~6.0 mg GAE/g dm in the untreated gel to 2.6–3.3 mg GAE/g dm after HIUS. Aloin showed a non-linear response, increasing from ~43 to ~48 mg/g at 28 W/cm² when processing time increased from 2.5 to 5 min, followed by an approximately 20% decrease at 7.5 min. Antioxidant activity ranged from 31 to 47% DPPH inhibition and 75 to 150 µmol TE/g ORAC. These findings indicate that moderate HIUS conditions improve selected functional properties while limiting bioactive compound degradation.

High-intensity ultrasound (HIUS) has emerged as a promising green technology for modifying the structural and functional properties of plant-based matrices. In this study, Aloe vera gel was subjected to HIUS at different acoustic intensities (11, 28, and 43 W/cm²) and processing times (2.5, 5, and 7.5 min) to evaluate its impact on techno-functional properties, rheological behavior, phenolic profile, and antioxidant activity. HIUS significantly reduced swelling capacity (up to ~60%) while enhancing water retention capacity (up to ~2-fold), depending on processing conditions. Rheological analysis revealed a decrease in viscosity associated with cavitation-induced depolymerization, followed by partial structural reorganization at moderate intensities. Total phenolic content and antioxidant activity were maximized at intermediate conditions (28 W/cm², 2.5 min), indicating enhanced release of bioactive compounds. However, excessive ultrasound intensity and prolonged processing led to a reduction in phenolic content, suggesting degradation effects. These findings demonstrate the presence of an optimal ultrasound treatment that balances structural modification and bioactive compound preservation, highlighting HIUS as an effective tool for tailoring the functional and antioxidant properties of Aloe vera-based ingredients.