| dc.description.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 | en_US |
