A benign process for the recovery of solanesol from tomato leaf waste

Solanesol, the precursor for the synthesis of coenzyme Q10, is currently recovered from tobacco leaves by conventional extraction techniques that require multiple purification steps and a large amount of organic solvents. We recently identified tomato leaves as an alternative source of solanesol and hypothesized that a high-pressure CO₂ extraction could be used as a clean extraction process. The effect of CO₂ pressure and temperature on the extraction of solanesol was determined to achieve high yield and purity. It was found that solanesol could be extracted efficiently by subcritical CO₂ at 25 °C from tomato leaves. The extract contained 40% solanesol and other active compounds such as vitamin K1. A higher level of purity of 93% was achieved using a secondary purification step. Different conventional methods for solanesol extraction was compared to determine the most efficient technique for production of solanesol from tomato leaf. The highest yield of solanesol was achieved at nearly 1% dry weight with using subcritical CO₂, which was superior to conventional methods.