New type of green extractant for oil production: Citric acid/citric acid sodium extraction system.

Developing green solvents with low toxicity and low energy consumption is an important issue for edible oil production. In this study, a novel extraction system, specifically a citric acid/citric acid sodium mixture, was developed for oil extraction from seed crops. Peanut and pumpkin seeds were used to evaluate extraction efficiency and more than 70% and 57% oils, respectively, were extracted from peanut and pumpkin seeds at 4 °C. After extraction, the oils floated on the surface of the solution and could be separated from the solvent system without evaporation. The extraction of edible oils was achieved without the use of toxic chemicals or energy-intensive equipment. This study provided a green and efficient method, and showed the potential of the proposed citric acid/citric acid sodium extraction system for production of edible oils from natural sources.