title: Effect of processing of black currant press-residue on polyphenol composition and cell proliferation.
abstract: The press-residue of black currants provides a good source of phenolic antioxidants. The purpose of this study was to optimize the extraction of phenolic compounds from the press-residue by use of extraction conditions compatible with food use. The effects of temperature, extraction duration, and use of ultrasound-assisted extraction on the juice yield, total phenolics (TP), and anthocyanin content of aqueous extracts were studied. Within the variables and response factors tested, the optimal conditions were a 15 min extraction at 90 °C. No significant effect from ultrasound-assisted extraction was found. The composition of anthocyanins and polyphenols was highly dependent on the extraction temperature. The percentage contribution of delphinidin- and cyanidin-3-rutinoside to TP had a negative linear correlation with temperature, while delphinidin- and cyanidin-3-glucoside had a positive linear correlation with temperature, with a maximum amount obtained at 80 °C and 55 °C, respectively. Furthermore, extracts obtained at higher temperatures showed a stronger inhibition of proliferation of Caco-2, HT-29, and HCT 116 cells than extracts obtained at lower temperatures. This may be due to the decomposition of complex polyphenols at higher temperatures, making them more accessible to the cells.
authors.affiliation: Nofima Mat AS, Aas, Norway. linda.holtung@nofima.no
authors.forename: Linda
authors.initials: L
authors.lastname: Holtung
authors.forename: Stine
authors.initials: S
authors.lastname: Grimmer
authors.forename: Kjersti
authors.initials: K
authors.lastname: Aaby
mesh_terms: D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D002851:Chromatography, High Pressure Liquid; D005419:Flavonoids / Q000032:analysis* / Q000494:pharmacology*; D006358:Hot Temperature; D006801:Humans; D010636:Phenols / Q000032:analysis* / Q000494:pharmacology*; D010936:Plant Extracts / Q000494:pharmacology*; D059808:Polyphenols; D031965:Ribes / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D013056:Spectrophotometry, Ultraviolet
chemical_list: D005419:Flavonoids; D010636:Phenols; D010936:Plant Extracts; D059808:Polyphenols