Optimized steam explosion treatment of tobacco stems for enhanced extraction of solanesol and nicotine

In this research, the Instantaneous Catapult Steam Explosion (ICSE) technique was utilized to fragment waste tobacco stems and enhance the solubilization of solanesol and nicotine, two bioactive compounds of interest. Statistical analysis revealed significant correlations between ICSE pressure (P = 0.043) and alkali dosage (P = 0.035) with solanesol yield. The optimal conditions for solanesol extraction were achieved under SE3 parameters (pressure 0.8 MPa, maintenance time 9 min, alkali dosage 5 %), resulting in a yield of 0.408 mg/g and an extraction rate of 99.03 %. To purify solanesol, two types of molecularly imprinted polymers (MIPs) were employed: Surface molecularly imprinted polymers (SMIPs) and bulk molecularly imprinted polymers (BMIPs). The SMIPs prepared through inverse emulsion polymerization exhibited superior performance for industrial-scale applications. These SMIPs retained their purification capacity after five reuse cycles, demonstrating their robustness and stability. For nicotine, the highest yield was obtained under SE1 conditions (pressure 0.8 MPa, maintenance time 5 min, and no alkali dosage), yielding 0.8 mg/g with an extraction rate of 72.7 %. Comparative analysis of the extraction rates indicates that nicotine might be concentrated through the direct condensation of vapors released during the ICSE pressure relief phase. Under the hypothesis that vapor condensation plays a critical role in nicotine concentration, the SE6 condition (pressure 1.0 MPa, maintenance time 9 min, alkali dosage 0 %) was the most favorable. Theoretical calculations suggest a yield of 0.9 mg/g and an extraction rate of 81.8 % under these conditions. This study introduces a novel and efficient approach for the extraction and purification of bioactive compounds from waste tobacco stems. It highlights the potential for sustainable utilization of agricultural by-products and advances the development of green chemistry processes.