  We explore the properties of central galaxies living in voids using the EAGLE
cosmological hydrodynamic simulations. Based on the minimum void-centric
distance, we define four galaxy samples: inner void, outer void, wall, and
skeleton. We find that inner void galaxies with host halo masses
$<10^{12}M_\odot$ have lower stellar mass and stellar mass fractions than those
in denser environments, and the fraction of galaxies with star formation (SF)
activity and atomic hydrogen (HI) gas decreases with increasing void-centric
distance, in agreement with observations. To mitigate the influence of stellar
(halo) mass, we compare inner void galaxies to subsamples of fixed stellar
(halo) mass. Compared to denser environments, inner void galaxies with $M_{*}=
10^{[9.0-9.5]}M_\odot$ have comparable SF activity and HI gas fractions, but
the lowest quenched galaxy fraction. Inner void galaxies with $M_{*}=
10^{[9.5-10.5]}M_\odot$ have the lowest HI gas fraction, the highest quenched
fraction and the lowest gas metallicities. On the other hand, inner void
galaxies with $M_{*}>10^{10.5}M_\odot$ have comparable SF activity and HI gas
fractions to their analogues in denser environments. They retain the highest
metallicity gas that might be linked to physical processes that act with lower
efficiency in underdense regions, such as AGN feedback. Furthermore, inner void
galaxies have the lowest fraction of positive gas-phase metallicity gradients,
which are typically associated with external processes or feedback events,
suggesting they have more quiet merger histories than galaxies in denser
environments. Our findings shed light on how galaxies are influenced by their
large-scale environment.
