Spray drying of the mountain tea (Sideritis stricta) water extract by using different hydrocolloid carriers

The water extract of the mountain tea was spray-dried by using different food hydrocolloids viz. beta-cyclodextrin (BCD), arabic gum (AG), and maltodextrins (MD 19 and MD12) as carrier materials. Powdered samples were then subjected to product yield, moisture content, water activity, bulk density, solubility, color (Lab) and SEM particle microstructure analyses. Furthermore, color (Lab), turbidity (NTU), total phenolic content (TPC), total antioxidant activity (TAA) and volatile compound (beta-pinene) analyses were performed on the reconstituted mountain tea samples. The product yield increased with the addition of the carrier materials whereas decreased at higher drying temperatures. The inlet air temperature of 155 C provided the better retention for beta-pinene. Almost all physicochemical properties of the spray-dried mountain tea samples were significantly (P < 0.05) affected by the inlet air temperature, the type and concentration of the carrier materials. (C) 2011 Elsevier Ltd. All rights reserved.