A Methodology for the Evaluation of Mechanical Properties of Sausage Based on Tensile and Compression Tests
The food product called sausage is a meat emulsion in which the fat drops are dispersed in an aqueous matrix containing soluble proteins, other muscle components and conjunctive tissue. The rheological behavior of sausage needs to be known in order to monitor the quality and acceptance of this product and the evaluation of its response, for instance, to different packaging situations, which is a result of their stress-strain behavior when subjected to a particular static or dynamic stress. A methodology for the assessment of mechanical properties of sausage has been developed. A universal testing machine was used and tests were carried out in sausage available in the market to validate the methodology. Tensile and compression tests were carried out and test conditions were varied, including strain rate and specimen shape and temperature. The influence of the skin on the determinations was also assessed. The need to control cross-section shape was identified, and a dumb-bell and a cylinder specimen shape were proposed for tensile and compression tests, respectively. Temperature is critical and higher temperatures decrease tensile and compressive strengths. Sausage resistance is also sensitive to the strain rate, especially at low values. A travel speed of 50 mm/min seems to be appropriate since variations around this value did not affect tensile or compressive strength determinations. The presented methodology was found adequate to the intended objectives, producing reliable and reproductive results.