A consecutive extraction of pectin and hesperidin from Citrus aurantium L.:Process optimization, extract mechanism, characterization and bio-activity analysis

With the proposal of the Paris Climate Agreement and double carbon policy, production enterprise is now facing green and low-carbon transformation. To promote green and low-carbon development, optimizing the production process and improving utilization rate of raw materials for the reduction of production cost is an significant technological path for the plant extract industry. Thus, the aim of this work was to develop a consecutive extraction process of pectin and hesperidin with lower cost and higher purity, as well as better properties of extract. The process parameters will be put forward through single-factor experiments, Plackett-Burman design and Box-Behnken design. The experimental results showed that the consecutive extraction process was effective and feasible. Pectin with excellent properties was obtained, and the solid-liquid ratio of extraction process parameters of hesperidin was reduced to 1:8 (g: mL). The problems of environmental pollution and high energy consumption in traditional extraction could be solved. The consecutive extraction process, an innovative, economic and environmental-friendly process, may be realized easily in industrial application. At the same time, the consecutive extraction process mechanism was revealed with the help of microscopy analysis of the plant tissue structure. The results demonstrated that preferential extraction of pectin process was helpful for the exposure and dissolution of hesperidin crystallization in cells and thus can improve extraction efficiency of hesperidin. The purity of the obtained hesperidin was up to 91.7%, which can be further purified depending on application requirements. A large amount of pectin was obtained (23.3% ± 0.5% yield), and the pectin has superior gel-property, strong antioxidant activity and certain antibacterial activity. The pectin and hesperidin obtained will have better application prospects in medicine and food because of their unique characteristics.