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 Ra 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.