SMB chromatography applied to the separation/purification of fructose from cashew apple juice

The simulated moving-bed (SMB) technology has been successfully used in separations in petrochemical, food and fine chemical industries. This work is intended to show a potencial economic alternative for the industrial processing of the cashew apple juice. The cashew tree is a native tropical plant abundant in Northeastern Brazil, whose commercial value relies mainly on the processing of its nut. The penduncle of the fruit is called the cashew apple. Despite its high nutrition value, around 90% of the crop spoils on the soil. Simulation and experimental results are presented for SMB separation of fructose from glucose, both present (~40 kg/m³) in the aqueous phase of comercial cashew apple juice. Kinetic and equilibrium data for fructose and glucose on packed columns using cation-exchange resins are reported. Experimental results for SMB operation indicate close to 90% purity in each product (fructose-rich extract and glucose-rich raffinate). Simulated unit performance and internal profiles agree well with experimental values. To increase the added-value and versatility of the products, either a step of isomerization of the raffinate or diverse SMB fluid-solid flowrate ratios may be applied. By this way, a wide range of products may be obtained, from nearly pure fructose to 42%, 55% and 90% solutions, which are the standard high fructose syrup concentrations. If solids content is conveniently raised to the usual HFCS (high fructose corn syrup) comercial standards, these products may be used as food additives, thus confirming a potentially attractive use of cashew apple juice