Assessment of carrier agents in terms of physicochemical, energy analyses and bioactive constituents of blackberry (Rubus fruticosus L.) powder processed by convective and hybrid drying methods

Abstract

In this study, the effect of maltodextrin, powdered sugar, and corn starch carrier agents used at different ratios (5% and 10%) in the convective dryer at 65 ºC and hybrid dryer (microwave + convective) at 350 W + 65 ºC to produce blackberry powder was investigated. Drying kinetics, energy analyses, physical, flow properties, and biochemical analyses of blackberry powder production processes were investigated. Drying rates in drying processes varied between 0.0052–0.0477 g moisture/g dry matter minute. Effective moisture diffusion values were determined between 3.36 × 10^–8-2.57 × 10^–7 m²/s. Specific moisture absorption rate and specific energy consumption values were found to vary between 0.0019–0.0034 kg/kWh and 237.15–530.00 kWh/kg, respectively. Tapped density was determined in the range of 1.666–2.765 g/ml, while bulk density was determined in the range of 1.319–1.937 g/ml. The wettability values of blackberry powders were found to vary between 2.00–27.67 s. Drying processes did not preserve the color values of fresh blackberry puree (p < 0.05). In bioactive findings, total phenol content values were 16.756–25.876 µg GAE/g⁻¹ dw, total monomeric anthocyanin values were 229–1.469 µg cy⁻³-glu/g⁻¹ dw, total flavonoid values 3.958–5.080 mg KE/kg dw and total antioxidant activity values 406–500 µmol TE/g⁻¹ dw.