title: Evaluation of the anthocyanin release and health-promoting properties of Pinot Noir grape juices after pulsed electric fields.
abstract: This study evaluated the health-promoting properties of Pinot Noir juices (Vitis vinifera L.) obtained at different maceration times after pulsed electric fields (PEF) using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and human intestinal Caco-2 cells assays. Juice quality, anthocyanins, total phenolics and vitamin C were also determined. The evaluation of bioprotective capacity of the juice against H2O2-induced oxidative stress in Caco-2 cells was determined using biomarkers for cellular health and integrity: cell viability and lactate dehydrogenase (LDH) leakage. Compared to untreated grape juice, PEF pre-treatment on grapes enhanced the release of the major anthocyanin found in Pinot Noir, i.e. malvidin-3-O-glucoside (+224%). Increase in the content of total phenolic (+61%) and vitamin C (+19%) as well as improvement in the DPPH scavenging activity (+31%) and bioprotective capacity (+25% for cell viability and +30% for LDH leakage) were observed in grape juices following PEF treatment. Bioprotective capacity determined by the cellular biomarkers had significant linear correlations with malvidin-3-O-glucoside content (0.71⩽r⩽0.73) whereas DPPH scavenging activity was not well correlated with malvidin-3-O-glucoside (r=0.30) and total phenolics (r=0.30). Therefore, evaluation of the bioprotective capacities using Caco-2 cell assay performed in this study makes a novel contribution to the current knowledge that demonstrates the capability of PEF technology to produce plant-based foods with better phytochemical composition and exhibiting the capacity to protect cells from oxidative stress.
authors.affiliation: Department of Food Science, University of Otago, PO Box 56, Dunedin 9054, New Zealand; Department of Botany, University of Otago, PO Box 56, Dunedin 9054, New Zealand.
authors.forename: Sze Ying
authors.initials: SY
authors.lastname: Leong
authors.affiliation: Department of Botany, University of Otago, PO Box 56, Dunedin 9054, New Zealand.
authors.forename: David John
authors.initials: DJ
authors.lastname: Burritt
authors.affiliation: Department of Food Science, University of Otago, PO Box 56, Dunedin 9054, New Zealand. Electronic address: indrawati.oey@otago.ac.nz.
authors.forename: Indrawati
authors.initials: I
authors.lastname: Oey
mesh_terms: D000872:Anthocyanins / Q000737:chemistry*; D000975:Antioxidants; D018938:Caco-2 Cells / Q000737:chemistry*; D004574:Electromagnetic Fields; D005638:Fruit / Q000737:chemistry*; D006801:Humans; D018384:Oxidative Stress; D010636:Phenols / Q000032:analysis / Q000737:chemistry*; D027843:Vitis / Q000737:chemistry*
chemical_list: D000872:Anthocyanins; D000975:Antioxidants; D010636:Phenols
keywords: Anthocyanins; Antioxidant activity; Caco-2 cells; Maceration; Oxidative stress; Pinot Noir; Pulsed electric fields