Given a minimal superalgebra A=Ass⊕J(A), any subsequence of the graded simple summands of Ass determines a homogeneous subalgebra of A which is still a minimal superalgebra. In the present paper we provide a sufficient condition so that the TZ2-ideal of graded polynomial identities satisfied by A factorizes as the product of the TZ2-ideals associated to its suitable homogeneous subalgebras of such a type. We use this fact to show that in this event A generates a minimal supervariety of fixed superexponent.