Improving nutritional quality, aroma profile and bioactive retention of rocket juice via thermosonication: a support vector regression-based optimization

This study investigates the application of thermosonication (TS) to improve the functional properties of roka (<i>Eruca vesicaria subsp. sativia</i>) water. Processing parameters, including time (8-16 min), amplitude (60-100%), and temperature (40-60 °C), were optimised using a comparative approach combining the response surface method (RSM) and support vector regression (SVR). The total phenolic content (TPC) increased to 86.04 mg GAE/100 mL with TS, representing an 8.1% rise compared to the control group and an 18.3% increase over pasteurization. Likewise, the total chlorophyll level reached 16.98 mmol TE/L from 9.67 g/100 mL, and <i>β</i>-carotene rose to 24.90 mg/100 mL (<i>p</i> < 0.05). Pasteurization caused losses of 15-30% in these components. In the phenolic profile, significant increases were observed in chlorogenic acid (42.05 μg/mL), caffeic acid (15.66 μg/mL), and quercetin (4.28 μg/mL). A total of 31 compounds were identified in aroma analysis; with TS treatment, levels of 3-Hexen-1-ol (15.70 μg/kg) and 1-hexanol (2.01 μg/kg) were preserved or increased. In <i>in vitro</i> digestion tests, the TS group demonstrated the highest bioavailability, even during the intestinal phase. For example, RSM demonstrated high compliance coefficients (<i>R</i> ² = 0.99), while SVR showed strong predictive performance (CV <i>R</i> ² = 0.84), particularly for FRAP. Overall, the results suggest that thermosonication is an innovative method for protecting and enhancing bioactive compounds in rocket juice.