Let A and B be unital C∗ -algebras. In this paper we obtain several operator inequalities providing upper bounds for the difference
∫Tϕt (f (xt)) dμ (t) -f(∫Tϕt (xt) dμ (t)),
where f : I ! R is a convex function defined on an interval I , (ϕt)t∈T is a unital field of positive linear mappings ϕt : A ! B defined on a locally compact Hausdorff space T with a bounded Radon measure μ and (xt)t∈T is a bounded continuous field of selfadjoint elements in A with spectra contained in I. Several Hermite-Hadamard type inequalities are given. Some examples for convex and operator convex functions are also provided.