The aim of the study was to assess the effect of the introduction of curing brine, massaging and pasteurisation on the dynamics of changes in collagen content and its thermohydrolysis rate in two bovine muscles with different topographic positions in the carcass: the semimembranosus muscle (m. semimembranosus) and the lumbar part of the longissimus dorsi muscle (m. longissimus lumborum). Brine contained, among other things, NaCl, phosphates and collagen protein. In the study the pH value of muscles, contents of crude protein and dry matter were determined together with the amount of collagen and its susceptibility to thermohydrolysis; moreover, shear force value was determined using the WBSF test. On the basis of the conducted tests it was found that the semimembranosus muscle contained more collagen than the lumbar part of the longissimus dorsi muscle. The introduction of brine, massaging and pasteurisation resulted in changes not only in its amount, but also in its susceptibility to thermohydrolysis. Curing resulted in a decreased rate of collagen thermohydrolysis in both analysed muscles in comparison to raw muscles: from several times in m. semimembranosus to around fifteen times in m. longissimus lumborum in terms of crude protein and over twenty times in relation to the total collagen content. The rate of collagen thermohydrolysis in both muscles varied: it was higher in m. semimembranosus than in m. longissimus lumborum. The most profound effect on changes in tenderness (test WBSF) was found for massaging, which in the semimembranosus muscle resulted in its decrease, while in the lumbar part of the longissimus dorsi muscle it caused an increase in comparison to the value obtained after the introduction of brine. It was found that after pasteurisation the dorsal muscle was more tender in comparison to the semimembranosus muscle in spite of the fact that it was characterised by a higher share of collagen in the total amount of protein.