title: Analytical strategy coupled with response surface methodology to maximize the extraction of antioxidants from ternary mixtures of green, yellow, and red teas (Camellia sinensis var. sinensis).
abstract: This work aimed at using a simplex-centroid design to model the effects of green, yellow, and red tea mixtures (Camellia sinensis var. sinensis) on metal chelation activity, phenolic composition, antioxidant activity, and instrumental taste profile. The regression models that described the extraction of flavan-3-ols, o-diphenols, total phenolic compounds (TPC), free radical scavenging activity toward 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), cupric ion reducing antioxidant activity (CUPRAC), and ferric reducing antioxidant power (FRAP) were significant, and data were fit satisfactorily (R(2) > 80%). A mixture of green and red teas had a synergism in CUPRAC and TPC, whereas a mixture of yellow and red teas had a positive effect on CUPRAC and DPPH. An optimization was performed to maximize the antioxidant activity and flavan-3-ol content and to render a tea with mild bitterness, and results showed that a mixture of 14.81% green, 56.86% yellow, and 28.33% red teas would be the most suitable combination of factors.
authors.affiliation: Department of Authenticity and Novel Foods, Institute of Food Safety, RIKILT, Wageningen University and Research Centre , P.O. Box 230, 6700 AE Wageningen, The Netherlands.
authors.forename: Daniel
authors.initials: D
authors.lastname: Granato
authors.forename: Raymond
authors.initials: R
authors.lastname: Grevink
authors.forename: Acácio A F
authors.initials: AA
authors.lastname: Zielinski
authors.forename: Domingos S
authors.initials: DS
authors.lastname: Nunes
authors.forename: Saskia M
authors.initials: SM
authors.lastname: van Ruth
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification*; D028241:Camellia sinensis / Q000737:chemistry*; D003300:Copper / Q000737:chemistry; D010084:Oxidation-Reduction; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D000975:Antioxidants; D010936:Plant Extracts; D003300:Copper
keywords: antioxidant activity; chemometrics; desirability function; electronic tongue; flavanols