Ultrasound-assisted emulsions with biopolymers for spray-drying of lemongrass essential oil

Abstract

The objective of this work was to evaluate the partial replacement of gum arabic by modified starches on the spray-drying microencapsulation of lemongrass (Cymbopogon flexuosus) essential oil. The ultrasound-assisted emulsions were prepared with 30% (w/w) of wall material, 7.5% (w/w) of oil load, and 1:1 (w/w) replacement ratio for all treatments. After 16 hours, the incompatibility observed between gum arabic and octenyl succinic anhydride (OSA) starch did not affect the obtained microparticles, since the treatment with OSA starch, partially replacing gum arabic, showed the best results for the process yield and for the oil charge retention after spray-drying process, and the treatment showed Newtonian viscosity close to that of the treatment prepared with gum arabic. Maltodextrin dextrose equivalent 10 (10DE) shows an oil load similar to that of the treatment with gum arabic, while the presence of maize maltodextrin DE20 reduces the content of encapsulated oil and the efficiency of the drying process due to the adherence of particles to the chamber. Therefore, the partial substitution of gum arabic is an alternative for the formation of emulsions, for the spray-drying microencapsulation of lemongrass essential oil.

Spray drying encapsulation of essential oils: Insights on various factors affecting the physicochemical properties of the microcapsules

“…Emulsion of lemongrass oil of varying viscosities was obtained using different gum types which showed that less viscous emulsion propels better atomization leading to the formation of better microcapsules. For example, emulsions of maize maltodextrin 20DE (0.0607 μ Pa·s) showed the best atomization followed by maize maltodextrin 10 DE (0.0717 μ Pa·s), cassava maltodextrin 10 DE (0.0803 μ Pa·s), modified starch Capsul™ OSA starch (0.1253 μ Pa·s) and GA (0.1778 μ Pa·s) 60 . It was evident that the structure and size of the gum molecule also influenced the encapsulation efficiency.…”

“…For example, emulsions of maize maltodextrin and GA (0.1778 μ Pa•s). 60 It was evident that the structure and size of the gum molecule also influenced the encapsulation efficiency.…”

Lemongrass essential oil micro‐ and nanoencapsulation for industrial application: Production techniques and potential applications

“…Due to its high cost, there are attempts to replace it with other materials. [17] Carvalho and collaborators [24,25] suggested the partial replacement of arabic gum by starch modified with octenyl succinic anhydride (OSA-starch) in a 1:1 ratio (w/w), which presented higher LEO retention (81.2%) than only arabic gum (67.5%), higher size distribution homogeneity, lower moisture content, and greater solubility. The oil retention was even better than the arabic gum/ maltodextrin combination (55%-67.5%), indicating the potential of using modified starch to obtain microcapsules by spray drying at a lower cost.…”

“…It could be explained by EO's high volatility, which leads to a minor loss during the spray drying using lower temperatures. The spray dryer inlet temperatures used by other authors to encapsulate LEO were 165°C, [27,28] 170°C, [23][24][25] and 180°C. [22] The spray dryer temperature directly influences the microparticle morphology, as high heating causes faster drying of the wall material compared with the core, which can produce cracks and pores on the surfaces of the particles, leading to oil leakage.…”