A green technology for the preparation of high fatty acid starch esters: Solid-phase synthesis of starch laurate assisted by mechanical activation with stirring ball mill as reactor

Starch laurate, a kind of high fatty acid starch ester, was directly produced by mechanical activation (MA)-assisted solid-phase synthesis (MASPS) technology with a customized stirring ball mill as reactor. The starch laurates with different degrees of substitution (0.0148-0.0412) were obtained under different reaction conditions. Fourier transform infrared spectroscopy confirmed that starch ester had been successfully produced by MASPS attributed to active hydroxy groups induced by MA. X-ray diffractometry and scanning electron microscopy showed that MA and esterification significantly disrupted the morphology and crystal structure of starch. Water absorption of starch was increased by MA but decreased by the introduction of laurate groups. Viscosity of starch was obviously reduced after both the processes of MA pretreatment and MASPS. The successful synthesis of starch laurate without the use of solvent and additives suggested that MASPS was a fast, simple, and green method for the production of high fatty acid starch esters.