High-pressure homogenization-assisted extraction of bioactive compounds from Ruta chalepensis

High-pressure homogenization (HPH) was investigated to promote the extraction in water of bioactive molecules from Ruta chalepensis, a medicinal plant widely used in folk medicine. Aqueous suspensions (5% wt) of the pre-milled plant were treated by high-shear mixing (HSM), followed by HPH at 100 MPa for up to 10 passes. A considerable decrease in the size of the suspended particles was observed when applying HPH, which was related to cell deagglomeration and fragmentation. In contrast, no significant changes at the cellular level were observed when only maceration or HSM treatments were applied. Remarkably, HPH treatment did not significantly change the antioxidant activity of the aqueous extracts, but affected their composition: HPLC analysis revealed that HPH treatment significantly increased the content in the aqueous phase of quercetin (+ 452.7%), recovered by fractionation of the aqueous phase with ethyl acetate, and rutin (+ 29.8%), recovered with butanol. In addition, GC/MS analysis of the chloroform fractions obtained from the aqueous extracts revealed that the HPH treatment caused also a significant (p < 0.05) increase in γ-fagarine and chalepin of + 177% and + 1420%, respectively, whereas pteleine, skimmianine, kokusaginine, and arborinine levels were higher in the extracts obtained by maceration than the HPH-treated samples. These findings suggest that the recovery of low water-solubility compounds from R. chalepensis, such as rutin and quercetin, as well as of some alkaloids, such as γ-fagarine and chalepin, significantly improved by HPH-assisted extraction and associated cell disruption effect.