Fluid bed drying of guarana ( Paullinia cupana HBK) extract: Effect of process factors on caffeine content
The aim of this study was to study the convective drying of the hydroalcoholic extracts obtained from powdered guarana seeds in a spouted bed dryer. The influence of process variables, such as the convective airflow rate, extract feed rate,; air inlet temperature, on the quality of the dry extract was determined using the caffeine; moisture content for the process evaluation. The caffeine content in the alcoholic; dried extracts was determined by capillary gas chromatography. The experiments were performed following a 3[3] factorial design; the data analyzed by response surface. The analysis of dry extract showed that the air; extract feed rates did not significantly affect (25% level) the caffeine content, but that drying temperature is a major factor to consider when the extract is submitted to fluid bed drying. Caffeine losses were significant (1% level) for drying temperatures above 120°C, while moisture content was lower than 3% for temperatures above 120°C. The data showed that there is an optimum temperature for the drying of guarana extracts in spouted beds,; under the conditions used in this study it was 120°C.
Renata S. Pagliarussi1?Jairo K. Bastos1?Luis A. P. Freitas1Email:lapdfrei@usp.br
[1] Faculdade de Ciências Farmacêuticas de Ribeiro Preto, Universidade de So Paulo, Via do Café s/n, 14040-903 Ribeiro Preto, So Paulo, Brazil
