A fragment of a study on the effect of raw material formulation on basic composition and rheological properties of model products is presented. The research material consisted of 14 model samples of mortadella, differing in raw material formulations. In the final product, the following determinations were carried out: the content of water, protein, fat, NaCl, total phosphorus, carbohydrates and collagen. The so-called non-variable indices – Feder number, i.e. water content / total protein content ratio (WC/PC), fat content / protein content ratio (FC/PC) and collagen / pro-tein content ratio (CC/PC), were calculated. Rheological properties of the products were examined by the CASRA method. From the 14 examined model products with differentiated raw material formulations, six satisfied chemical requirements for “bologna mortadella”. Correlation calculations between the parameters of the examined products and raw material formulation–modelling factors showed that factor A2, i.e. participation of pork stomachs in the composition of raw materials, was best correlated with the mentioned discriminants. Pork stomachs which were characterized by the highest water content (83.3%) and the lowest total protein (13.3%) and fat (2.8%) content in relation to the remaining raw meat materials had more distinct modifying effect on chemical and rheological characteristics of the examined products as compared to the addition of lean shoulder (A1) and tendinous beef (A3), the basic compositions of which are considerably less differentiated. Factor A2 affected most of the examined parameters and it was the most important moderator of chemical and rheological properties of the examined model products.