Shengnan Ji,Dong Uk Ahn,Yunlong Zhao,Kai Li,Shugang Li,Xi Huang
Five major proteins from egg white were separated using a successive extraction/precipitation protocol. The yield and purity of the separated proteins were measured. The separated proteins were confirmed by MALDI-TOF-MS, and their structures were characterized by CD spectrum. Lysozyme was first separated using FPC 3500 resin and then ovomucin from the lysozyme-free egg white. Ammonium sulfate and citric acid were added to the resulting lysozyme- and ovomucin-free egg white solution to precipitate ovotransferrin. Ovomucoid and ovalbumin were separated from the resulting supernatant using ethanol. The separated proteins were further purified and the optimal conditions for the further purifications were suggested. The purity and yield of lysozyme, ovotransferrin, ovalbumin, and ovomucoid were higher than 90% and 77%, while those of ovomucin were about 72% and 75%, respectively. This study separated five major proteins in egg white successively using resin adsorption, pH adjustment, salt/ethanol precipitation, and ultrafiltration.
A large volume of waste mercury chloride catalyst (HgCl2) is generated by calcium carbide-based polyvinyl chloride production in China, which accounts for 30% of global mercury consumption. However, there are few studies on the leaching behavior and risk control of waste catalyst where mercury is in the form of HgCl2, which is more soluble than metal mercury and poses great threat to human health and environment. This study investigated mechanochemical stabilization and leaching behavior of waste mercury catalyst using sulfur as additive. We found that mercuric sulfide (HgS) formed through mechanical milling, although the reaction between HgCl2 and S is not thermodynamically favored. Moreover, toxicity characteristic leaching procedure (TCLP) results showed mercury leaching values are lower than the TCLP limit value of 0.2 mg/L after mechanochemical treatment. Results of sequential extraction procedure showed that ball mill could transfer more than 99.9% of the Hg in the catalyst to the least mobile fraction.
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.
危险品化学品经营许可证（带存储）