Garlic extract nanoformulation intended for broiler growth performance

Abstract

Garlic and clove essential oils (EOs) have gained attention from swine and poultry producers, as a replacement to antimicrobial growth promoters (AGPs) because AGPs pose a threat to animal and human health. However, EOs are not simple compounds, but rather they are a mixture of various compounds, with concentrated hydrophobic liquids containing volatile aromatic compounds. Hence, the objectives of the study were to design and optimize garlic essential oil nanoemulsion (GEON) by the Taguchi method and spontaneous emulsification method using a high speed homogenizer because these methods are easy, fast and reduce chemical usage waste. Further, GEON antimicrobial and antioxidant activity were enhanced by adding clove essential oil (CEO). The physicochemical characteristics of nanoemulsion such as droplet sizes, composition and morphology were measured. Surfactant concentrations (3, 5 and 7%), oil-surfactant mixing ratio (1:4, 1 :8 and 1 :24), type of surfactant (Tween® 20, Tween® 80 and Pluronic® F68) and stirring speed (10000, 15000 and 20000) were selected as important factors influencing the droplet size and polydispersity index (PDI). The type of surfactant showed a greater effect on the particle size and PDI for the GEON preparation. The optimised experiment yielded a mean droplet size of 28.41± 0.91 nm with PDI of 0.315± 0.02 and zeta potential of 28.5± 1. 15 mV. The compatibility of the garlic essential oil and Tween® 80 was ascertained by FTIR. Furthermore, GC-MS showed the presence of the important compounds of garlic in GEON. Taguchi L-9 approach was revealed to be an easy and useful tool to optimise the various parameters investigated. GEON showed an improvement in both antioxidant and antimicrobial activity. The addition of CEO increased the droplet size to 271± 0.47 with a PDI 0.132± 0.054 and it showed to be more stable with the zeta potential of 22.4± 3.62 mV. The combination also demonstrated higher antioxidant and antimicrobial activity when compared to GEON. This research suggests that the garlic and clove essential oil nanoemulsion (GCEON) has the potential to be developed as broiler growth promoter