Application of molecularly imprinted hydrogel for the preparation of lactose-free milk.

BACKGROUND

A variety of lactose imprinted hydrogels were prepared and their binding properties were studied in comparison with blank non-imprinted hydrogel. Methacrylamide and ethylene glycol dimethacrylate were used as functional monomer and cross-linker, respectively. Dimethylsulfoxide was also applied as polymerisation solvent.

RESULTS

Different template/monomer ratios were studied and the optimised imprinted hydrogel (MIP₂), with a lactose/methacrylamide ratio of 1:8, was selected in a rebinding test. In Scatchard analysis of MIP₂-lactose interactions, the dissociation constant and maximum binding sites were 0.33 mmol L⁻¹ and 67.76 µmol g⁻¹ hydrogel, respectively. The selectivity of MIP₂ for lactose in aqueous media was also evaluated in comparison with different mono- and disaccharides. The data showed that the affinity of MIP₂ for lactose is significantly higher than other saccharides. The imprinted hydrogel was finally used as a sorbent for separation of lactose from milk.

CONCLUSIONS

The results indicated that MIP₂, as an optimised imprinted hydrogel, can effectively bind lactose and decrease its concentration in milk.