Chemical Engineering

Inulin is a mixture of fructose polysaccharides, which is synthesized inside of plants as an energy reserve. Its physicochemical, functional and technological properties are exploited in food and pharmaceutical industry. Novel extraction techniques are investigated to obtain inulin because they reduce time, energy consumption and improve extraction yields. Inulin from jicama (Smallanthus sonchifolius) roots and cabuya (Agave americana) meristem was obtained using conventional extraction (CE), microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE). Firstly, CE was done to determine the suitable non-conventional extraction technique for each plant. MAE was selected for jicama and UAE for cabuya. The variables considered for MAE were microwave power, S:L ratio and temperature; and S:L ratio temperature and ultrasonic amplitude for UAE. In all extraction techniques soluble matter yield was the response variable. The best conditions to extract inulin by CE for jicama were 130 rpm, 75°C, 1:5 S:L and 25 min; and for cabuya were 80°C, 300 rpm, 1:5 S:L and 100 min. In the other hand, the best MAE extraction conditions were 90 W, 1:15 S:L and 80°C; and for UAE were 60°C, 1:20 S:L and 30% ultrasonic amplitude. When extraction techniques were compared, UAE achieved a higher yield (62%) than CE (52%) at the same time (10 min); and extraction time using MAE was shorter than CE to obtain the highest yield (12,12%), 13 and 25 minutes, respectively. Finally, inulin extract was purified, dried and characterized by FTIR, DSC and TGA for each technique.