Microencapsulação de óleo essencial de capim-limão (Cymbopogon citratus (DC.) Stapf) por spray drying.

Abstract

The essential oil of Cymbopogon citratus (DC.) Stapf (OECC) for presenting antimicrobial and antioxidant properties, is a promising raw material for the development of drugs and food additives. However, its high volatility and susceptibility to oxidative degradation are the main disadvantages that limit its use. Spray drying microencapsulation is a technique that promotes protection of the biological, functional and chemical properties of encapsulated materials. Thus, the objective of this study was to encapsulate the OECC by spray drying, to evaluate the effect of drying conditions (inlet temperature: 130 to 160 ° C, OECC concentration: 5 to 15%, and maltodextrin concentration: 10 to 20%) in relation to humidity, yield, water activity, color, morphology, particle size, encapsulation efficiency, phenolic content, antioxidant activity, antimicrobial activity and thermal analysis of the OECC microspheres, as well as optimize the process . When evaluating the impact of drying conditions on the encapsulated material, it was observed that the analyzed parameters were significantly affected (p <0.05) by the inlet temperature (the increase in temperature significantly influenced the reduction of antioxidant activity), OECC concentration (the elevation of the OECC concentration significantly influenced the increase in the values of humidity, water activity and total phenolic content), and the concentration of maltodextrin (higher concentrations of maltodextrin increased the process encapsulation efficiency). The observation of the ultrastructural aspects of the microspheres revealed spherical external morphology, without cracks and apparent pores. The pure OECC and the microencapsulated OECC showed antimicrobial activity against E. coli and S. aureus strains. With the optimization of the spray drying process, the following values were determined as ideal conditions for the OECC microencapsulation process: inlet temperature of the 148ºC process, 15% maltodextrin concentration and 10% oil concentration. Under these conditions, a process with 41.63% encapsulation efficiency, 3189.189ug/g of total phenolic content and 40.37mg/100g of antioxidant activity will be obtained, such conditions can be applied as a useful guide for production large-scale industrialization of OECC microspheres with antimicrobial and antioxidant potential.