title: An enzymatic extraction of proanthocyanidins from País grape seeds and skins.
abstract: Proanthocyanidins (PAs) from the skins and seeds of País grapes were obtained by enzymatic extraction by using three enzymes (pectinase, cellulase and tannase) and an enzymatic blend to increase the phenol concentrations and reduce the PA molecular size. The total phenol concentrations (as indicated by Folin-Ciocalteu reagent), mean degree of polymerisation (mDP), galloylation percentage (%G) and structural proportion (phloroglucinolysis) were analysed, in addition to the extract's capacity to inhibit angiotensin I-converting enzyme (ACE) activity. On grape skins, pectinase had the greatest effective on the release of total phenols, to 0.01g/ml solid/liquid (S/L) and 1% enzyme/substrate (E/S). On grape seed, the three enzymes were effective in increasing the phenolic extraction (p<0.05). The effects of enzymes on the mDP and %G of the extracts were related to their enzymatic activity. All the extracts inhibited ACE, but ACE inhibition was thought to be improved by the increased number of terminal units in the seed samples.
authors.affiliation: Bioengineering Laboratory, Department of Chemical Engineering, Faculty of Engineering, Universidad de Concepción, Barrio Universitario s/n, P.O. Box 160-C, Concepción 4030000, Chile. Electronic address: kfernandeze@udec.cl.
authors.forename: Katherina
authors.initials: K
authors.lastname: Fernández
authors.affiliation: Bioengineering Laboratory, Department of Chemical Engineering, Faculty of Engineering, Universidad de Concepción, Barrio Universitario s/n, P.O. Box 160-C, Concepción 4030000, Chile.
authors.forename: Marco
authors.initials: M
authors.lastname: Vega
authors.affiliation: Bioengineering Laboratory, Department of Chemical Engineering, Faculty of Engineering, Universidad de Concepción, Barrio Universitario s/n, P.O. Box 160-C, Concepción 4030000, Chile.
authors.forename: Estrella
authors.initials: E
authors.lastname: Aspé
mesh_terms: D055162:Biocatalysis; D002265:Carboxylic Ester Hydrolases / Q000737:chemistry; D002480:Cellulase / Q000737:chemistry; D005638:Fruit / Q000737:chemistry; D010936:Plant Extracts / Q000032:analysis / Q000302:isolation & purification*; D011096:Polygalacturonase / Q000737:chemistry; D044945:Proanthocyanidins / Q000032:analysis / Q000302:isolation & purification*; D012639:Seeds / Q000737:chemistry*; D027843:Vitis / Q000737:chemistry*
chemical_list: D010936:Plant Extracts; D044945:Proanthocyanidins; D002265:Carboxylic Ester Hydrolases; C022711:tannase; D011096:Polygalacturonase; D002480:Cellulase
keywords: Angiotensin I-converting enzyme; Enzymatic extraction; Grape proanthocyanidins