Experimental production of annatto powders in spouted bed dryer

A new method for the production of annatto powders by drying the alkaline aqueous extracts in a spouted bed was studied. The effects of drying conditions such as air inlet temperature and extract feed rate on the properties of the powder obtained were investigated. The powder properties taken as quality parameters were the bixin and moisture content and the particle size distribution. Results on total through-put, bixin content and recovery obtained showed that spouted bed drying of aqueous extracts is advantageous when compared to extraction by mechanical attrition. Also the data showed that above the drying temperature of 80 degreesC the bixin content decreases sharply. The particle sizes of the powder were always below 60 mum. (C) 2003 Elsevier Science Ltd. All rights reserved.