Introduction:

The biological activity of the thyme essential oil is known to work as growth promoter on broilers, but its direct applicability on production is difficult due to its instability associated to its volatilization.

Aim:

To develop a micro-encapsulated thyme essential oil and its performance in diets for broiler chickens.

Methodology:

The technique used for the microencapsulation was the spray drying process, using the Gum Arabic (GA), Maltodextrin (M) or Starch Yam succinate (SYS) as biopolymers. The emulsification conditions (previous step to the micro-encapsulation) and the conditions to obtain the microparticles were stablished, through the implementation of a statistical experimental design (SED) The formulation obtained under defined conditions is additionally characterized in terms of morphology, stability, release behavior and field performance.

Results:

The biopolymer matrixes GA/M and GA/M/SYS were selected for the covering material of the microparticles. The encapsulation efficacy was 87.5 %, its particle size was 74.5 [zm, the dispersity index 2.4 and a yield of 48,5%. The stability test proved that polymeric cover exerts some protection to the loss of the essential oil. The release studies demonstrated the release modulation of the active ingredient. The field study proved that the microparticulate system presents a statistical behavior like the commercial product used as comparator.

Conclusion:

This approach suggests that this microencapsulation method could be used as a growth promoter in the production of broiler chickens.