Changes in bioactive compounds concentration and physicochemical properties of mango smoothies treated by ultrasound

Mango smoothies prepared with whole milk (WM-MS) or soymilk (SM-MS) were processed by ultrasound (400 W, 24 kHz, 100 µm amplitude for 20 min at 35 and 55 °C) in order to evaluate the effects on physicochemical parameters (pH, total soluble solids and total acidity) and bioactive compounds content (carotenoids and isoflavones). Regardless of the temperature applied and the milk used in the formulation, significant changes in physicochemical parameters were observed in sonicated smoothies. While the pH values slightly decreased from 5.58 to 5.45 (WM-MS) and 5.64 to 5.59 (SM-MS), total soluble solids and acidity augmented approximately 5 – 6 % and 3 – 5 %, respectively. Carotenoid concentration significantly diminished in sonicated smoothies, observing higher degradation in the SM-MS (58 %) than in the WM-MS (40 %) when treated at 55 °C. Otherwise, a significant increase in total isoflavone content (6 %) was detected in SM-MS after processing. Additionally, higher aglycone than glucoside concentration was detected in sonicated SM-MS. The application of ultrasound combined with mild heat in mango smoothies induce physical and chemical changes that can modify their bioactive compound profile.

Keywords: ultrasound, fruit-based smoothies, carotenoids, isoflavones.