Simple microencapsulation of plant essential oil in porous starch granules: Adsorption kinetics and antibacterial activity evaluation

In this work, corn porous starch was used as a food grade polymer to microencapsulate essential oil (EO), the effects of temperature on adsorption of EO were investigated, and adsorption kinetics curves were plotted. Using this approach, the sustained-release antibacterial effects of porous starch microcapsules containing EOs (PSM-EOs) against Penicillium roqueforti and Aspergillus niger were explored under accelerated volatilization under high temperature conditions, and microencapsulation was successfully applied to bread preservation. The results showed that temperature had a significant effect on the adsorption capacity, and adsorption rate was controlled by both liquid film diffusion and intraparticle diffusion. The activation energy (Ea) of the adsorption process was 7.96 K J/mol as calculated using the Arrhenius equation. The results of antibacterial experiments showed that PSM-EOs exhibited superior sustained-release antibacterial effects and significantly prolonged the shelf life of bread, compared with controls. Practical applications The spoilage caused by mold contamination is a serious challenge for the bread industry. At present, the main preservative used in baking products is calcium propionate, a chemical preservative. However, calcium propionate can be decomposed to produce propionic acid under the action of intestinal microorganisms. Propionic acid is an important factor in inducing diabetes mellitus. Therefore, it is necessary to explore new preservation techniques rather than bread with calcium propionate. In this paper, porous starch microcapsules containing essential oil were prepared, and the adsorption kinetics curve of porous starch to essential oil was plotted. On this basis, the inhibition effect of porous starch microcapsules containing essential oil in high temperature accelerated volatilization on the main mold (P. roqueforti and A. niger) causing bread corruption was investigated. The aim is to provide new ideas for bread preservation.