Scalar matrix elements involving strange quarks are studied in several
models. Apart from a critical reexamination of results obtained in the Nambu
and Jona-Lasinio model we study a scenario, motivated by instanton physics,
where spontaneous chiral symmetry breaking is induced by the flavor-mixing 't
Hooft interaction only. We also investigate possible contributions of virtual
kaon loops to the strangeness content of the nucleon.Comment: 12 pages, latex style. One figure, available from the author upon
request. University of Regensburg TPR-94-0