title: Aqueous extraction kinetics of soluble solids, phenolics and flavonoids from sage (Salvia fruticosa Miller) leaves.
abstract: In the present study, aqueous extraction kinetics of total soluble solids (TSS), total phenolic content (TPC) and total flavonoid content (TFC) from Salvia fruticosa leaves were investigated throughout 150 min. of extraction period against temperature (60-80 °C), particle size (2-8 mm) and loading percentage (1-4 %). The extract yielded 25 g/100 g TSS which contained 30 g/100 g TPC and 25 g/100 g TFC. The extraction data in time course fit with reversible first order kinetic model. All tested variables showed significant effect on the estimated kinetic parameters except equilibrium concentration. Increasing the extraction temperature resulted high extraction rate constants and equilibrium concentrations of the tested variables notably above 70 °C. By using the Arrhenius relationship, activation energy of the TSS, TPC and TFC were determined as 46.11 ± 5.61, 36.80 ± 3.12 and 33.52 ± 2.23 kj/mol, respectively. By decreasing the particle size, the extraction rate constants and diffusion coefficients exponentially increased whereas equilibrium concentrations did not change significantly. The equilibrium concentrations of the tested parameters showed linear behavior with increasing the loading percentage of the sage, however; the change in extraction rates did not show linear behavior due to submerging effect of 4 % loading.
authors.affiliation: Department of Food Engineering, Faculty of Engineering, Akdeniz University, 07059 Antalya, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Torun
authors.affiliation: Department of Food Engineering, Faculty of Engineering, Akdeniz University, 07059 Antalya, Turkey.
authors.forename: Cuneyt
authors.initials: C
authors.lastname: Dincer
authors.affiliation: Department of Food Engineering, Faculty of Engineering, Akdeniz University, 07059 Antalya, Turkey.
authors.forename: Ayhan
authors.initials: A
authors.lastname: Topuz
authors.affiliation: Department of Food Engineering, Faculty of Engineering, Akdeniz University, 07059 Antalya, Turkey.
authors.forename: Hilal
authors.initials: H
authors.lastname: Sahin-Nadeem
authors.affiliation: Department of Food Engineering, Faculty of Engineering, Akdeniz University, 07059 Antalya, Turkey.
authors.forename: Feramuz
authors.initials: F
authors.lastname: Ozdemir
keywords: Extraction kinetics; Flavonoids; Phenolics; Sage; Salvia fruticosa