Tiliroside is a natural polyphenolic compound with a wide range of biological activity, and defatted strawberry seeds are its rich source. The goal of this study was to optimize accelerated solvent extraction (ASE) conditions, including temperature, solvent composition, and the number of extraction cycles, using Box–Behnken design to maximize the yield of tiliroside. UPLC-DAD-MS was applied to investigate the polyphenolic composition of the extracts, and preparative liquid chromatography (pLC) was used for isolation. All obtained mathematical models generally showed an increase in the efficiency of isolating polyphenolic compounds with an increase in temperature, ethanol content, and the number of extraction cycles. The optimal established ASE conditions for tiliroside were as follows: a temperature of 65 °C, 63% ethanol in water, and four extraction cycles. This allowed for the obtainment of a tiliroside-rich fraction, and the recovery of isolated tiliroside from plant material reached 243.2 mg from 100 g. Our study showed that ASE ensures the isolation of a tiliroside-rich fraction with high effectiveness. Furthermore, defatted strawberry seeds proved to be a convenient source of tiliroside because the matrix of accompanying components is relatively poor, which facilitates separation.
In this study a multi-residue determination method for 36 pesticides in dried hops was reported. The sample preparation procedure was based on the acetate buffered QuEChERS method. A few mixtures of dispersive solid phase extraction (dSPE) sorbents consisting PSA, C18, GCB, Z-Sep and Z-Sep+ were investigated to clean-up the supernatant and minimize matrix co-extractives. The degree of clean-up was assessed by gravimetric measurements, which showed the best results for mixtures containing the Z-Sep+ sorbent. This is the first study to apply Z-Sep+ sorbent for hops material and the first to improve the method for pesticide residues determination in hops. Samples were analysed using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) and the procedure was validated according to the SANTE/11813/2017 document at four concentration levels: 0.02, 0.05, 0.1 and 1 mg/kg. The limits of quantification (LOQ) were in the range of 0.02–0.1 mg/kg. For all active substances, the trueness (recovery) ranged from 70 to 120% and the precision (RSDr) value was <20%. Specificity, linearity and matrix effect were also evaluated. The validated method was applied to the analysis of 15 real dried hop samples and the relevant data on detected residues were included.