Thermodynamic approach of meat freezing process

Autores UPV
Año
Revista Innovative Food Science & Emerging Technologies

Abstract

Frozen storage is a method widely implemented in meat industry in order to maintain the nutritional value and sensorial characteristics of meat products. The aim of this research was to implement and validate the use of the infrared technique as a non-destructive control tool to monitor the physicochemical phenomena that occurred during the freezing stage. This enables to evaluate the final impact of this operation in a complex system such as meat. To do this, the evolution of the freezing process in pork loin (Longissimus dorsi) was followed by a thermographic camera Optris PI¿ 160 thermal imager (Optris GmbH, Berlin, Germany), whose spectral infrared range of wavelength is comprised between 7.5 and 13 μm. The results obtained have demonstrated the existence of a chemical potential gradient which caused an internal flux of water. In turn, as a result of nucleation phenomena and the influence of the surface tension existent, a new water chemical potential gradient appeared, leading to the displacement of water molecules towards the ice agglomerates. This provoked the progressive dehydration of the tissue areas immediately close to the ice crystals. Micrographs obtained in different positions of the meat tissue confirm this theory.