  Let $\omega$ be a differential 1-form defining an algebraic foliation of
codimension 1 in projective space. In this article we use commutative algebra
to study the singular locus of $\omega$ through its ideal of definition. Then,
we expose the relation between the ideal defining the Kupka components of the
singular set of $\omega$ and the first order unfoldings of $\omega$. Exploiting
this relation, we show that the set of Kupka points of $\omega$ is generically
not empty. As an application of this results, we can compute the ideal of first
order unfoldings for some known components of the space of foliations.
