Vol 105, No 11 (2016)

The structure of a single equation of state meeting the scaling theory of critical phenomena was based on the phenomenological theory of a critical point and Benedek’s hypothesis. In the framework of the approach offered to the problem a single equation of state for refrigerant R32 was developed in the range of temperatures 138...420 K. It was shown that at that approach not only a regular part of the thermodynamical surface and neighborhood of critical point but the region of metaequilibrium states of refrigerant R32 were described. The results of a thermal surface and isochoric heat capacity of state for refrigerant R32 were cited.

The most of the meat raw materials are sold and stored in frozen state. The quality estimation methods don’t provide sufficient necessary information. Herewith the use of histological analysis is extremely limited due to the absence of a State standard on microstructural investigations of frozen meat. The methods of microstructural analysis on the basis of a modified histological engineering developed by the authors allow estimating the characteristics of frozen meat quality rather quickly and objectively using the determination of the quantity and localization of crystallizing moisture in tissue structures. The article examines the results of using a histological analysis when estimating crystals formation in meat in case of frequent repeated freezing after defrosting. Also the features of crystals formation in meat of different quality groups (NOR, PSE, DFD) are presented, the data on the muscular tissue porosity of these meat groups are given too. The results of studies showed that repeated freezing of meat led to more significant destructive changes of membrane and filament structures of muscular tissue fibers as compared with single freezing. The further task of study is a quantitative analysis of water crystallization and influence of temperature variations on this process at storage. The article is illustrated by microstructural images of meat frozen raw materials obtained by the methods of light microscopy and scanning electronic microscopy.