To use endogenous myrosinase in Carica Papaya
seed to convert benzyl glucosinolate (BG)
to benzyl isothiocyanate (BITC) and then extract it for further studies.
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.
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
The result showed that benzyl isothiocyanate was formed under the optimized conditions
and was no doubt the basic component of the extraction.