Solvent screening and extraction conditions prediction of subcritical extraction based on improved model: Extraction of lycopene as a case

In recent years, subcritical extraction has developed rapidly due to its environmental friendliness and high efficiency. In the extraction of low-polar and non-polar active substances, the addition of green low-polar solvents to subcritical extraction solvents can increase the yield of active substances. However, solvent screening and extraction conditions prediction are still a challenge. In this study, we employed the Williams formula to incorporate temperature and pressure correction into the Hansen solubility parameter to screen solvent under subcritical conditions by energetic spatial distance R a between the solvent and solute. Then, an improved model along with corresponding dissolution factor e was established which allowed the prediction of optimum extraction condition range under subcritical conditions. Eventually, we chose the thermosensitive and non-polar substance lycopene as experimental case. Results showed that an e of 0.71 under experimental optimum extraction condition was within the predicted high extraction range, indicating the accuracy of the model predictions.