Thermosonication of tangerine juice: Effects on quality characteristics, bioactive compounds, and antioxidant activity

Abstract

This study aimed to evaluate the effect of thermosonication (TS) on tangerine juice using an ultrasonic bath (US, 35 kHz, 750 W) at 50°C/5 min, 50°C/10 min, 60°C/5 min, and 60°C/10 min, besides juice pasteurized at 85°C/5 min as control. The TS increased the titratable acidity, total soluble solids, and improved the juice homogeneity (p ≤ .05), with discreet changes in the color parameters (L*, chroma, and hue). The treatment at 60°C was more effective against microbial growth, regardless of the processing time. Polyphenols and ascorbic acid remained at higher concentrations in the TS-treated samples when compared to the control (p ≤ .05), while lower carotenoids level was observed in the treatment at 50°C/5 min (p ≤ .05). TS-treated samples presented better antioxidant activity (p ≤ .05) when compared to the control. Thus, TS treatment (60°C/5 min) may be a promising alternative for the preservation of bioactive compounds in tangerine juice. Practical applications Several emerging technologies have been studied as alternatives to the conventional pasteurization of juices, like ultrasound, ultraviolet radiation, supercritic carbon dioxide, and high pressure hidrostatic. This study demonstrated that thermosonication (TS) can be used in the processing of tangerine juice using temperature of 60°C for 5 min, which exhibited the microbiological characteristics equivalent to the conventional pasteurization (85°C/5 min), without impairing the physicochemical and preserving the bioactive compounds, thus improving the antioxidant activity of the juice. The study contributes to recent research that suggests TS as a promising technology to be adopted in the fruit juice industry.