The Extraction Using Deep Eutectic Solvents and Evaluation of Tea Saponin.

Simple Summary: In order to improve the comprehensive utilization of oil tea seed meal and increase the comprehensive economic benefits of the oil tea industry. In this paper, the low eutectic solvent was used as the extraction system, and the ultrasonic extraction method was combined with the enzymatic method to jointly extract the tea saponins. It was further purified with a large-pore adsorption resin to develop a set of environmentally friendly, energy-saving, and efficient tea saponin extraction and purification processes. On this basis, the tea saponins extracted from oil tea seed meal were further analyzed for antioxidant capacity and bacteriostatic activity. The results provided the scientific experimental basis and theoretical support for the efficient use of oil tea by-products. Tea saponins have high surface-active and biological activities and are widely used in chemicals, food, pharmaceuticals, and pesticides. Tea saponins are usually extracted using ethanol or water, but both methods have their disadvantages, including a negative impact on the environment, high energy consumption, and low purity. In this study, we explored an effective process for extracting tea saponins from tea meal using deep eutectic solvents combined with ultrasonic extraction and enzymatic techniques. The experimental results showed that a high extraction efficiency of 20.93 ± 0.48% could be achieved in 20 min using an ultrasonic power of 40% and a binary DES consisting of betaine and ethylene glycol (with a molar ratio of 1:3) at a material–liquid ratio of 1:35 and that the purity of the tea saponins after purification by a large-pore adsorption resin reached 95.94%, which was higher than that of commercially available standard tea saponin samples. In addition, the extracted tea saponins were evaluated for their antioxidant and bacteriostatic activities using chemical and biological methods; the results showed that the tea saponins extracted using these methods possessed antioxidant properties and displayed significant antibacterial activity. Therefore, the present study developed a method for using deep eutectic solvents as an environmentally friendly technological solution for obtaining high-purity tea saponins from tea meal oil. This is expected to replace the current organic solvent and water extraction process and has great potential for industrial development and a number of possible applications. [ABSTRACT FROM AUTHOR]