title: Optimization and prediction of antioxidant properties of a tea-ginger extract.
abstract: A response surface approach was used to investigate the effects of temperature, concentration, and time on the antioxidant properties (total flavonoid (TF), total phenol (TP), peroxide scavenging activity (PS), iron chelating activity (IC), DPPH radical-scavenging ability (DPPH), ABTS assay (ABTS)) of aqueous extract of tea-ginger (2:1) powder. Color indices, pH, and redox potential of the tea-ginger powder were also measured and used as independent variables for the prediction of antioxidant properties of the extract using ordinary least square (OLSR), principal component (PCR), and partial least square (PLSR) regression. The R (2) values for TP, TF, ABTS, and PS response surface models were 0.8873, 0.9639, 0.6485, and 0.5721, respectively. The OLSR, PCR, and PLSR were able to provide predictive models for DPPH, TP, and TF of the tea-ginger extract (P < 0.05). The PLSR gave the most parsimonious model with an R (2) of 0.851, 0.736, and 0.905 for DPPH, TP, and TF, respectively.
authors.affiliation: Department of Food Science and Technology, Federal University of Technology Akure, Nigeria.
authors.forename: Solomon Akinremi
authors.initials: SA
authors.lastname: Makanjuola
authors.affiliation: Department of Food Science and Technology, Federal University of Technology Akure, Nigeria.
authors.forename: Victor Ndigwe
authors.initials: VN
authors.lastname: Enujiugha
authors.affiliation: Department of Food Science and Technology, Federal University of Technology Akure, Nigeria.
authors.forename: Olufunmilayo Sade
authors.initials: OS
authors.lastname: Omoba
authors.affiliation: Department of Biochemistry, Federal University of Technology Akure, Nigeria.
authors.forename: David Morakinyo
authors.initials: DM
authors.lastname: Sanni
keywords: Antioxidant; color; hue index; multivariate regression; response surface methodology; tea-ginger extract