One-pot process for simultaneously obtaining oil and sinigrin from field pennycress (Thlaspi arvense) seeds using microwave-assisted biphasic extraction

Abstract

In the present study, microwave-assisted biphasic extraction (MABE) was first and successfully applied to the simultaneous extraction of oil and sinigrin from field pennycress (Thlaspi arvense) through a one-pot process. Four potentially influencing factors on the yields of oil and sinigrin, including the ratio of lower phase to solid, ratio of upper phase to solid, microwave irradiation power, and microwave irradiation time, were selected for further optimization by Box–Behnken design, and the optimal extraction conditions were obtained as follows: ratio of lower phase to solid of 21 mL/g, ratio of upper phase to solid of 12 mL/g, microwave irradiation power of 389 W, and microwave irradiation time of 33 min. Under the optimal extraction conditions, the yields of oil (23.46 % ± 0.78 %) and sinigrin (18.42 ± 0.35 mg/g) from T. arvense seeds were maximized. The GC–MS analysis illustrated that the T. arvense seed oil obtained by MABE using n-hexane and water biphasic solvents and Soxhlet extraction using n-hexane solvent exhibited a similar fatty acid composition. The seed oil acquired by the efficient MABE demonstrated a higher quality due to its lower acid value and higher iodine value. Scanning electron microscopy results showed that the cell structure of seed tissues was obviously disrupted compared with untreated raw material and that treated by the conventional extraction method. In general, the results indicated that the proposed MABE is an efficient method for the extraction of oil and sinigrin from T. arvense seeds.