From high oleic vegetable oils to hydrophobic starch derivatives: I. Development and structural studies

Hydrophobic starch derivatives were obtained by biocatalysed esterification with hydrolysates from high oleic vegetable oils. First, the pure rapeseed oil or waste rapeseed oil, was hydrolysed with a Thermomyces lanuginosus lipase in the buffer solution form. Next, purified hydrolysates were used as donors of the acyl group for the esterification of potato starch after being pregelatinised in ionic liquid - 1-buthyl-3-methylimidazolium chloride. The esterification was catalysed by the same fungal lipase but immobilised on a polymer carrier and conducted in the anhydrous ternary reaction system: hydrophilic ionic liquid - non-ionic surfactant - hydrophobic higher fatty acids. The products have been identified and characterised using the following methods: degree of substitution (DS) by volumetric and elemental analysis method, FTIR and NMR spectroscopies, XRD and SEM. The proposed method can lead to the synthesis of more water-resistant starch derivatives as well as provide a possibility for recycling waste oils from the food industry.