LIPID PHASE OF DRY SAUSAGES AS A FACTOR IN THE FORMATION OF TRANSPORT BARRIERS DURING DRYING

Abstract

Drying is a decisive stage in the production technology of dry sausages, as it determines their physicochemical, structural–mechanical, sensory, and microbiological characteristics. In classical technological approaches, the control of the drying process is focused primarily on external environmental parameters (temperature, relative humidity, air flow velocity), while the internal structure of the sausage batter is considered a result of random formation during raw material comminution and mixing. In particular, the role of the lipid phase remains insufficiently studied and is traditionally assessed only in terms of fat content and average particle size. In this work, a conceptually new interpretation of the lipid phase of dry sausages is proposed, considering it as a system-forming element of the internal transport architecture of the product. It is substantiated that fat performs the function of a drying multibarrier, combining diffusive, thermal, and geometric resistance to mass and heat transfer. It is demonstrated that the decisive factor governing dehydration kinetics is not only the fat content, but primarily the topology of its spatial distribution within the meat matrix. Based on the analysis of literature data and the generalization of transport properties of the constituent phases, it is established that the moisture diffusion coefficient in the lipid phase is 2–3 orders of magnitude lower than that in muscle tissue, while the thermal conductivity of fat is 2–2.5 times lower. This leads to an increase in the effective diffusion path length, higher mass transfer tortuosity, and the formation of local zones with reduced drying rates. As a result, heterogeneous moisture and temperature fields develop within the sausage cross-section, causing nonlinear drying behavior and increased variability in the quality of the final product. The study formulates a system of scientific hypotheses describing the relationship between lipid phase topology, the multibarrier drying effect, and the effective intensity of moisture diffusion. A transition is proposed from empirical regulation of drying regimes to an engineering-based approach founded on the purposeful design of the internal transport architecture of dry sausages by controlling the shape, size, and spatial organization of lipid inclusions. The obtained results provide a scientific basis for the further development of dry sausage drying technologies with predictable kinetic and quality characteristics.