  At small-x, the structure function F_L(x,Q2) is driven by the gluon content
of the nucleon target and consequently it can unravel the underlying QCD
dynamics in that region. In this work, one studies its behavior on photon
virtuality Q2 at fixed energy within the color dipole formalism for models
considering parton saturation effects. The reason is that they resum a wide
class of higher-twist contributions, which have important influence in F_L
description towards low Q2. It is shown that the geometric scaling property
holds for the longitudinal cross section. Moreover, the effective anomalous
dimension in scaling dipole cross sections can be investigated by studing both
the turn over and the large Q2 regions of the recent experimental measurements.
