Purpose: To use endogenous myrosinase in
Carica Papaya
seed to convert benzyl glucosinolate (BG)
to benzyl isothiocyanate (BITC) and then extract it for further studies.
Methods: Process variables including seed powder particle size, sample-to-solvent ratio, pH of buffer
solution, enzymolysis temperature, enzymolysis time were investigated using single-factor experiments
and response surface methodology coupled with Box-Behnken design for further optimization of
conversion conditions. The formed benzyl isothiocyanate was extracted by steam distillation method
and purified by thin-layer chromatography (TLC). Relevant process variables were also studied. Finally,
the purified benzyl isothiocyanate was analyzed by gas chromatography-mass spectrometer (GC-MS)
and compared to BITC standard.
Results: Optimum enzymolysis conditions were seed powder particle size, 90 - 120 μm; sample-tosolvent
ratio, 1:20; pH of buffer solution, 4.8; enzymolysis temperature, 40°C; and enzymolysis time, 27
min. Enzymolysis liquid was steam-distilled for 2 h, extracted twice using dichloromethane (DCM) (using
3 times the volume of distillate each time) as extractant. Finally, 1:20 was adopted as the optimal
dichloromethane-petroleum ether (DCM-PE) elution proportion to wash out the unnecessary
compounds.
Conclusion: The result showed that benzyl isothiocyanate was formed under the optimized conditions
and was no doubt the basic component of the extraction.
