Ultrasound-assisted extraction of natural antioxidants from sugar beet leaves (beta vulgaris L.) to delay lipid oxidation in soybean oil

It has been recognized that sustainability and environmental impact of agricultural food chain need a valorization of the food by-products. Therefore, there is a growing interest in exploring their potential applications across different sectors within a circular economy framework. Given that food byproducts are a rich source of bioactive compounds, there is a notable focus on extracting these compounds from them, rethinking their new life. Currently, various extraction techniques are employed to recover bioactive compounds .In this study, the use of green technologies for the extraction of bioactive compounds was comprehensively reviewed, first. Then, the utilization of ultrasound-assisted extraction (UAE) as a green method to extract natural antioxidants from sugar beet leaves (Beta vulgaris L.) was investigated and compared with a conventional method. Finally, the obtained extract was used to enhance the oxidative stability of soybean oil. The extraction efficiency was evaluated by measuring total phenolic content (TPC), Antioxidant activity with radical scavenging activity (DPPH) method, and chlorophyll content of the extracts. The findings demonstrated that UAE yields more phenolic compounds than the conventional method, with significant improvements observed in TPC and antioxidant activity. After choosing the most optimal extraction condition by varying the concentration of ethanol as the extracting solvent, the chosen extract was applied to the soybean oil, and we found that there was an outstanding delay in lipid oxidation compared to the control group. In conclusion, this research highlights the key elements to advancing extraction techniques for obtaining natural antioxidants from food byproducts. The findings emphasize the potential capability of UAE for extracting antioxidant-rich compounds from plant tissues. Moreover, the enhanced oxidative stability of soybean oil using the obtained natural extract shows the possibility of substituting the synthetic antioxidants with those obtained from natural sources.