Resumen
- Spray drying is a technique commonly used to produce powdered phytopharmaceutical ingredients from medicinal plants. Product quality is related to operating conditions and the drying carriers used. Bidens pilosa L. is a South American plant with proved antiinflamatory, antimalaric, antitumoral and hepatoprotector activities. The aim of this work was to optimize the processing variables inlet drying temperature, plant extract feed flow rate and drying composition on the properties of the powdered B. pilosa compositions. Experimental planning, regression and multiple response analysis were used in data processing and to optimize the drying conditions. The responses evaluated were total flavonoid content, antioxidant activity, concentration of selected plant compounds, particle size, residual moisture content, solubility, flow properties, product recovery and drying efficiency. Results showed that inlet drying temperature was the factor that showed significant influence in most of the responses. The concentration of the bioactive marker compounds monitored decrease conversely with inlet spray drying temperature. Powders obtained at low inlet drying temperatures presented higher residual moisture and particle size, favouring flow properties. The optimized conditions based on the mathematical models fitted to experimental data were: Aerosil®:Cellulose 13:37%, extract feed rate 8.95 mg/min and inlet gas temperature of 155.2 °C.