The extraction of tobacco protein from discarded tobacco leaf by hollow fiber membrane integrated process

Plant leaf protein, especially soluble protein in tobacco leaves, has high nutritional and medicinal value, and has been gradually applied in the food field as an important source of food protein. In this study, tobacco protein was extracted and purified from discarded tobacco leaf by hollow fiber membrane integrated process. Hollow fiber ultrafiltration (UF), nanofiltration (NF) and osmosis reverse (RO) membranes were prepared and used to extract and desalinate to obtain the high-purity tobacco protein. The derived wastewater was filtered by hollow fiber osmosis reverse (RO) membrane for harmless treatment. Experimental results showed that tobacco protein rejections by UF membrane and NF membrane could reach 87.9 and 98.5%, respectively. When diluted twelve times, the concentrated protein solution could be effectively desalinated by UF membrane with a low protein loss rate of 13.89%. All membranes suffered inevitable fouling. Using combined physical washing and chemical cleaning could effectively recover membrane water flux.