Bioguided extraction of polyphenols from grape marc by using an alternative supercritical-fluid extraction method based on a liquid solvent trap

Abstract

The biological activity of polyphenols extracted from grape marc was studied with a view to finding a new use for this winery waste. Polyphenols were extracted by using an alternative supercritical-fluid extraction method based on the use of a liquid trap that allows extracted polyphenols to be retained in a saline buffer, thus avoiding the need for the organic solvent required to elute polyphenols from a solid trap. The major extraction variables influencing the performance of the liquid trap (viz. CO(2) modifier content, flow-rate, extraction time and trap volume) were optimized. The proposed method was applied to the supercritical-fluid extraction extraction of 0.3 g grape marc with CO(2) modified with 3% methanol at 350 bar at 50 degrees C (CO(2) density 0.9 g mL(-1)) for 20 min, using a liquid flow-rate of 0.9 mL min(-1). The polyphenol extracts thus obtained exhibited cytotoxic effects that induced apoptosis in tumour cells.

Analysis of Flavonoids in Functional Foods and Nutraceuticals

“…115 Pressures typically applied in SFE of polyphenols vary from 9.5 to up to 65 MPa, and temperatures from 408C to up to 808C. [115][116][117][118][119][120][121][122] However, recovering efficiencies are not always improved with respect to conventional solvent extractions. 118,121 Moreover, the optimal conditions depend on the type of compounds to be extracted and the nature of the sample matrix, and thus need to be carefully set up for every sample.…”

“…The use of appropriate cosolvents or modifiers can overcome this limitation, by enhancing the solubility of target polar analytes and improving extraction selectivity. Methanol in varying proportions (from 3% to up to 40%) is the modifier of choice in the extraction of flavonoids from foods and medicinal herbs, [115][116][117][118][119][120] although ethanol (10%-15%) has also been employed. 121,122 The use of these cosolvents allows operation at lower pressures.…”

Application of supercritical CO2 in lipid extraction – A review

“…Applications of SFE include analytical-scale extractions and screening, as well as pilot-scale extraction. Palenzuela et al (2004) applied SFE to the isolation of polyphenolic compounds from grape marc, the grape waste remaining after wine fermentation. They used SC-CO 2 with a methanol modifier to achieve rapid extraction under relatively mild conditions.…”

Application of supercritical fluid extraction for separation of nutraceuticals and other phytochemicals from plant material

“…One of potential sources of flavonoids is grape and its by-pruducts. Several authors researched the extraction of flavonoids from grape and grape by-products [83][84][85][86][87][88][89][90][91][92][93]. Results obtained from these researches can majorly contribute to grape-processing industries and wineries in terms of giving information on how to achieve a higher recovery of some flavonids extracted with SFE, besides those obtained in grape processing.…”