Performance Evaluation of Banaba [Lagerstroemia speciosa (L.) Pers.] Leaf Extract Spray Drying
Mari Rowena Castaneda-Tanquilut1, Jessie C. Elauria2, Engelbert K. Peralta3, and Neil C. Tanquilut4
Process variables affecting the spray drying attributes of liquid extract from complete banaba extract were investigated. The levels of the process variables namely pump speed, air inlet temperature and decoction ratio was incorporated into a Box-Behnken incomplete factorial experiment. Dependent variables were drying capacity, recovery rate and product moisture content. Pump speed and air inlet temperature significantly affected product moisture content and recovery rate. Drying capacity was significantly affected by pump speed and decoction ratio.
A set of criteria namely, the highest drying capacity, less than or equal to 10% product moisture content and maximum product recovery rate was considered for the rehydration and organoleptic characteristics of spray dried banaba powder. Decoction ratios of 1:7 (1 g leaves to 7 g water) and 1:3, respectively at 13,000 rpm pump speed and 120 degree Celcius inlet temperature, satisfied the said criteria. However, with these two treatments, the resulting spray dried powder samples rated poor in terms of sinkability and dispersibility, although these exhibited good solubility and were not significantly different in their rehydration and organoleptic characteristics.
The system’s thermal energy loss during spray drying was 1,208.57 kJ/h, using the mass and energy balance equations which indicates an efficient drying system.
Keywords: spray drying, banaba powder, response surface methodology (RSM)
1,4Assistant Professor III, and Assistant Professor I, Institute o Engineering and Computer Studies, and Institute Veterinary Medicine, respectively, Pampanga Agricultural College, Magalang, Pampanga, Philippines; 2Professor, 3Associate Professor, ABPROD, Institute of Agricultural Engineering, College of Engineering & Agro-Industrial Technology, University of the Philippines Los Baños, 4031 College, Laguna, Philippines.