Effect of Sonication Treatments on Freshly Squeezed Mandarin Juice Quality Parameters

In this study, sonication treatment at 35 kHz for 0, 5, 15, 30, and 60 minutes (at 20°C) and thermal pasteurization at 95°C for 15 seconds were applied to freshly squeezed mandarin juice to determine the effects on physicochemical properties, bioactive compounds, and other quality parameters. The changes for pH, titratable acidity, water activity, browning index, total flavonoids, antioxidant activity, ascorbic acid contents, color, and cloud (in sensory analysis) were insignificant. However, increases in viscosity, ash, turbidity, and color values and decreases in enzyme activities were observed after the sonication treatment. Overall, for 15 minutes treatment, significant enhancement in total phenolics and ascorbic acid content was observed. Results suggest that 15 minutes of sonication treatment could contribute to the improvement of the quality of mandarin juice and therefore, it is possible to employ this treatment in mandarin juice processing successfully.