In this work we perform direct numerical simulations of three-dimensional
magnetohydrodynamics with a background magnetic field, representing solar wind
plasma, and introduce test particles to explore how a turbulent electromagnetic
environment affects them. Our focus is on the terms of the electric field
present in the generalized Omh's Law that are usually dismissed as unimportant.
These are the Hall and the electronic pressure (EP) terms, but we concentrate
primarily on the latter. We discover that the EP term generates an acceleration
of the particles, which represent protons, in the direction parallel to the
background magnetic field, in contrast to the known preferential perpendicular
energization. By studying the electric field itself, we are able to detect the
type of structures of the EP field that produce such parallel acceleration.
These are thin and elongated structures placed on top of a monotonic and
near-zero background. A statistical study to understand the real significance
of the electronic pressure term is also performed