Effect of high frequency ultrasounds on lycopene and total phenolic concentration, antioxidant properties and α-glucosidase inhibitory activity of tomato juice

Tomato juice was subjected to high frequency ultrasounds(378 and 583 kHz)at increasing energy densities (up to 250 MJ/m³). Results relevant to the treatments at high frequency providing an energy density of 250 MJ/m³ were compared with those obtained at 24 kHz delivering the same energy density. Lycopene and total phenolic concentration, as well as the α-glucosidase inhibitory activityof tomato juice, were not affected by ultrasound regardless the frequency and energy density. However, the antioxidant properties were negatively affected by high frequency ultrasounds.