Abstract
An automated accelerated salting-out assisted solvent extraction (A-ASASE) was developed. This approach made full use of the advantages of both the accelerated solvent extraction (ASE) technique and salting-out assisted liquid-liquid extraction (SALLE), without any modifications at the level of the ASE machine. The A-ASASE combined an automated extraction at high temperature/pressure and an enrichment step using eco-friendly solvents (e.g., water and ethanol) in a fully integrated and simple way that required only low volumes of solvents. The A-ASASE was successfully applied to extract three stilbenoids, namely E-resveratrol, E-Δ-viniferin and E-vitisin B, present in grapevine (Vitis vinifera L.) by-products as a proof-of-concept compound. First, factors affecting the yield of stelbenoids by SALLE were investigated by means of a design of experiment model (DOE). The SALLE was then incorporated into ASE. Various ASE operational parameters such as temperature and number of cycles were also investigated. The highest yield was obtained using a mixture of ethanol-water, 70:30 (v/v) at 60 °C, using three extraction cycles and with 5 min of contact each. The highest yields of stilbenoids were 5.87 ± 0.28 g kgâ1 dry weight, 3.27 ± 0.72 g kgâ1 dry weight and 1.81 ± 0.2 g kgâ1 dry weight for resveratrol, E-Ï”-viniferin and vitisin B, respectively. The A-ASASE was then successfully applied to extract the same stilbenoids from the roots of Vitis vinifera L. These results highlight the applicability of A-ASASE methodology to the extraction and enrichment of the extract in compounds of medium-high polarity in an easy and fully automated way.