Within the framework of a relativistic covariant quark model the effects of two novel quark interactions on the light-flavoured baryon mass spectra as well as on a multitude of observables, such as electroweak form factors, helicity amplitudes, decay amplitudes, magnetic moments and charge radii, are studied. This quark model is based on the so-called Bethe-Salpeter equation, which describes bound-state systems in quantum field theory. After a brief summary of the basic ingredients of the quark model, we discuss the results published so far. Then we introduce two different forms for alternative interactions. This is the major subject of this thesis: In addition to the so-called confinement potential and an instanton-induced 't Hooft interaction a novel spin-flavour dependent interaction motivated by pseudoscalar meson-exchange is introduced. Thereby we assume, that pseudoscalar octet and singlet mesons interact with quarks via pseudoscalar coupling. Assuming a short-range Gaussian potential in coordinate space, we introduce only three additional model parameters: The octet and singlet-coupling strength as well as the range of this interaction. It is found, that this additional spin-flavour dependent interaction leads to a better description of the light-flavoured baryon mass spectra than has been obtained so far. It also improves the description of the electroweak form factors and helicity amplitudes as well as of the other observables mentioned above. A second interaction is studied, which corresponds to a modification of the spin dependence of the confinement potential by introducing specific spin-spin and tensor contributions. This modified confinement potential was used in combination with the instanton-induced 't Hooft interaction and with the novel spin-flavour dependent interaction as well. Although not superior to the results found with the new spin-flavour dependent interaction as mentioned above, also for models with a modified confinement potential a, compared to the previous results, improved description of both the spectra and electroweak observables was found
