Recovery of Linamarin by Adsorption of Cassava Extract onto Activated Carbon

Abstract

The unavailability of linamarin and its use in various applications such as determining the cyanide content in cassava flour and chips and measuring glucose in biomedical applications and hydrogen cyanide in the environment using linanmarin/linamarase/SnO2 electrode biosensors have necessitated its recovery from cassava tissues. A 0.2 μm membrane was used at a filtration rate of 1.44 mL/min for the initial isolation of linamarin, followed by extract adsorption onto activated carbon. U-shaped isotherms were observed for the adsorption of bulk cassava jelly-like solid (BJS) extract onto activated carbon. The phenomenon can be described by the selective adsorption of the solvent (B) while the solute (A) is left concentrated, resulting in an initial increase in A until equilibrium is reached and A starts to drop. This process in which the concentration of the solute in the presence of the solvent results from competitive adsorption (solute−solvent) is referred to as surface excess adsorption. Integration of the results from both 1H NMR and IR analyses indicates that the product was linamarin. The decomposition temperature of the purified product was found to be in the range of 138−140 °C, which corresponds to values reported in the literature. The Freundlich empirical adsorption equation was used to simulate surface excess adsorption where values of the volume of solute per mass adsorbed (v) at 25 and 65 °C were found to be 0.434 and 3.950 mL/g, respectively. In comparison, the values calculated using the Freundlich equation fitted the experimental data quite well.