Preparation of Hydrophobic Porous Starch and Its Oil Absorption Properties

Abstract:

Hydrophobic porous starch was successfully prepared in this paper by the combination of enzymatic hydrolysis pretreatment, octenyl succinic anhydride (OSA) modification and Al3+ cross-linking. The effects of enzyme addition amount on the structure, physicochemical properties, and the oil absorption capacity of hydrophobic porous starch were studied. Results showed that the synergistic treatment of α-amylase and amyloglucosidase made holes on the surface structure of corn starch granules, and the porous starch was formed. Under the same OSA addition, the degree of substitution of the hydrophobic porous starch decreased with the increase of enzyme dosage. The results of laser confocal microscope showed that the octenyl succinic acid (OS) groups were distributed throughout the particles after esterification, and the OS groups tended to distribute inside the hydrophobic porous starch granules with the increase of hydrolysis rate. In addition, the oil absorption rate of hydrophobic porous starch increased with the increase of hydrolysis rate, and the maximum oil absorption rate could be 52.30%. The adsorption rates of corn oil, engine oil and diesel oil were 80.41%, 52.30% and 41.93%, respectively. In the oil-water system, the water absorption rate was only about 6%, indicating good oil-water selectivity and oil retention ability were realized.