Microencapsulação de eugenol em materiais biodegradáveis/biocompatíveis por spray-drying

Abstract

Due to its antimicrobial, antioxidant and natural compound properties, eugenol is indicated as a substitute for synthetic additives in food. However, because it is unstable to external agents, its use is compromised in industrial processing. Thus, encapsulation becomes a viable alternative so that it can be applied and its obtaining conditions must be investigated. This study aimed to evaluate the effect of the combination of maltodextrin (MD) and bovine serum albumin (BSA) on eugenol microencapsulation by spray-drying. A full factorial design (23) with triplicate in the central point was used varying the concentrations of MD (5 to 15%), BSA (0.5 to 1%), and eugenol (0.2 to 0.6%), aiming to optimize the responses of eugenol percent recovery (REC), and eugenol encapsulation efficiency (EE), determined by UV-Vis spectroscopy. The analysis of estimated effects and the response surface methodology allowed to observe that the increase of the concentration of the three studied variables resulted in the reduction of EE, while for REC, the concentrations of BSA and eugenol also affected its reduction; however, the MD had a positive effect. Through the analysis of desirability, it was possible to define the optimal condition for obtaining eugenol microcapsules maximizing REC and EE (MD = 10%; BSA = 0.5%; eugenol = 0.2%), with REC close to 45%, and EE close to 92%. The microcapsules exhibited wrinkled morphology visualized by scanning electron microscopy analysis, and average size between 1.3 and 4.2 µm, determined by the dynamic light scattering technique. The microcapsules were characterized in terms of water activity (<0.1575), moisture (<3.06%), hygroscopicity (<16.11 g water 100 g-1), and solubility (<160 s), exhibiting adequate values for spray-dried products. Thermogravimetric and infrared analysis confirm the thermal stability and encapsulation efficiency of the microcapsules, respectively. The experimental conditions studied demonstrated that the eugenol encapsulation process was efficient, allowing the increase of its stability for industrial application.