Development of wall material for the microencapsulation of natural vanilla extract by spray drying

Background and objectives: The aim of this study was to develop a wall material using rice starch (Oryza sativa) to optimize the microencapsulation of vanilla extract by spray drying. Native starch rice was hydrolyzed, succinated, extruded, and characterized. Findings: The peak viscosity of modified starches was reduced from 3,875 cP to <100 cP by effect of the modification step. Native starch was gelatinized by extrusion according to gelatinization enthalpy (?H J/g). Natural vanilla extract was encapsulated, and the most optimal conditions for the drying process were air inlet temperature of 125C, 14.0% of total solids, and 86.2% of encapsulation efficiency. The scanning electron microscopy evidenced the formation of microcapsules; however, the confocal laser scanning microscopy showed no interaction between the wall material and the vanilla extract. This could be related to the zeta potential values of the vanilla extract and the wall material. Conclusions: Modified rice starch is a potential wall material for the encapsulation of different bioactive compounds in the food sector. Significance and novelty: Chemical and physical modifications such as hydrolysis, succinylation, and extrusion in native rice starch offer adequate properties to achieve 86.2% encapsulation efficiency of natural vanilla extract using spray drying.