To produce soft cheeses without maturation from a mixture of dairy and non-dairy raw materials of high quality it is necessary to be aware of the changes that occur in the protein phase of the milk during the production process. As you know, one of the fundamental parameters for soft cheeses is the consistency of the resulting product.
In this regard, it is of interest to investigate the structure of cheese by electron microscopic methods. These cheeses differ in their microstructure from other types of cheese, in which the structure of the protein phase has an agglomerated-globular character [65, 66].
Microstructure cheese is formed under influenced by The microstructure of the cheese is formed as a result of manufacturing and ripening. Properties such as cohesiveness and plasticity are closely related to it [126]. Cheese microstructure affects technological properties such as shrinkage, diffusion of salts, lactic acid and protein breakdown products between different parts of the cheese mass. The main elements of interest in the microstructure of cheese are the macrostructural and the microstructural [71]. Macrostructural (macro grains, intergranular interlayers , micro voids) and microstructure (fat and lipoid particles, salt deposits and colonies of microorganisms) basic elements в
the microstructure of cheese [14].
As a result, micro-photographs were taken and the microstructure of cheese samples made from a mixture of cow's and goat's milk as well as with the addition of extruded chickpea flour was studied.
Goat milk differs from cow's milk in its protein composition. The lacto-albumin fraction in goat milk is considerably higher than in cow's milk. The lacto-globulin fraction predominates in cow's milk. It is known that the ratio of proteins determines the structural-mechanical properties of the clotted product. The consistency of goat's milk cheese also differs
of the consistency of cow's milk. If the whey protein content is high, the goat milk product has a more delicate consistency. It can be seen that goat milk does not form a thick clot when clotted. The consistency is characterised by a flaky, delicate texture, which means that the microstructure is also different from that of cow's milk cheese (figure 13).
Figure 13 - Microstructure of soft cheese samples: a - from cow's milk; b - from goat's milk
The microstructure of soft cheese samples made from cow's milk is shown in figure 13; it can be seen that the structure is characterised by rather large deposits of calcium salts.
The figure shows the 14microstructure of a soft cheese made from a mixture of cow's and goat's milk, which has a more homogeneous structure. The figure also shows micro voids, which are finer in comparison to the cow's milk sample. In fresh soft cheese with chickpea flour, fine flour deposits in the form of granules were found (figure b14).
Figure14 - Microstructure of soft cheese samples:
a - from a milk mixture; b - with extruded chickpea flour Thus, the microstructural properties of the cheeses at the interface were investigated
of several macro grains. Their number seems to influence the formation of the cheese pattern, which is characterised by the shape and position of the eyelets. As a rule, eyelets are formed in the gaps between the grains (picture 15).
Figure 15 - Microstructure of soft cheese samples Micro-organisms of the bacterial leaven used for production
The development of soft cheeses creates tiny micro voids between the cheese grains, and the accumulation of gases in the micro voids in the cheese clot leads to the formation of eyelets.
In soft cheese samples, the fat component is evenly distributed in the form of small inclusions. The dispersion of the fat components in soft cheese samples is determined by the structure of the protein clot. Fat is known to fill the cells in the mesh structure of the protein gel (Figure 16).
Figure16 - Fat deposits in soft cheese samples
In the figures it can be seen that the fat is incorporated into the structure of the protein clot. It can be assumed that when the samples are prepared for microscopy, the fat is slightly melted out of the protein structure and deformed. Its structural outline and location can be seen in the photographs.
Thus, based on the research carried out, certain structural regularities of formation and distribution of all elements of cheese microstructure as well as their binding capacity can be concluded. The absence of visual observation of micropores in samples of soft cheese without ripening in the microstructure indicates a high content of the mass fraction of moisture in the product (from 45%).
