  The latest results from PLANCK impose strong constraints on features in the
spectrum of the curvature perturbations from inflation. We analyse the
possibility of particle production induced by sharp turns of the trajectory in
field space in inflation models with multiple fields. Although the evolution of
the background fields can be altered by particle production, we find rather
modest changes in the power spectrum even for the most extreme case in which
the entire kinetic energy of the scalar fields is converted into particles.
