English Physicochemical characterization and antioxidant activity of matrices of specialty coffees (Coffea arabica) produced in the corregimiento Cay-Ibagué-Tolima, Colombia

The objective of this work was to physiochemically characterize and quantify the content of phenols, caffeine, and antioxidant activity in beans from samples of roasted and ground specialty coffee, associated with the production systems of the Corregimiento Cay in Ibagué. (5) samples of roasted and ground coffee, which were related as specialty coffee types: Blend (2), Castillo (2), and Tabi (1). The physicochemical parameters evaluated were color (CIElab), electrical conductivity, solids, fixed and volatile solids, soluble solids, hydrogen potential (pH), moisture, water activity, acidity and equivalent acidity (3-caffeoylquinic), reducing and non-reducing sugars, ether extract, phenols flavonoids, and reducing power (FRAP). The results of the characterizations showed 2.54±0.33%, for soluble solids, water activity 0.241 to 0.280, and reducing sugars 1.10 to 1.85%. CIELab color (L: 20.8 ± 0.50 to 22.3 ± 0.20; a*: 3.15 ± 0.35 to 4.65 ± 0.91; b*: 9.40 ± 0.28 to 9.40 ± 0.28), pH 4.79 to 5.54, chlorogenic acid equivalents 8.66 ± 1.10 and 10.5 ±1.60 mg/kg, caffeine 246.9± 9.62 mg per 100 g, being higher in the Blend and Tabi type samples and the phenols and flavonoids with values of 258.2± 41.7 (mg E. gallic A. per 100) and 258.2 ± 41.7 (mg E. quercetin per 100 g) respectively. Electrical conductivity and total inorganic conductive solids showed a positive correlation in the varieties studied. Final FRAP test (μM/g) 696.3± 13.1. Multivariate analysis and correlation between parameters are proposed as an analytical model for the characterization of coffee matrices and show the quality and variability of the samples associated with the regions.