Improvement of microwave-assisted hydrolysis of cassava pulp and tapioca flour by addition of activated carbon

The superior effects of addition of activated carbon were evidenced for microwave assisted hydrolysis of starches in cassava pulp and tapioca flour under hydrothermal conditions varying irradiation temperature (160–230 °C at 5 min), duration of heating time (5–18 min at 210 °C) and amount of activated carbon at 0.5–2.0:1:20 of activated carbon:solid:liquid ratio. The presence of 1.0 g/g in microwave-assisted hydrolysis gave much improved glucose yields (44.49% for cassava pulp and 71.93% for tapioca flour) at lower heating temperature (220 °C and 200 °C, each for 5 min) with suppressed formation of secondary decomposed compounds than those without addition of activated carbon (32.41% in cassava pulp at 230 °C and 55.11% in tapioca flour at 240 °C, each for 5 min). The highest glucose yield from cassava pulp (52.27%) was obtained after heating at 210 °C for 15 min.