Measuring the Eating Quality of Meat
A number of factors affect meat eating qualities, both in terms of the way the animals are reared and at the processing stage of production. Several studies have shown that the highest ranked eating-quality characteristic is meat tenderness. Subjective measurements of this characteristic are made by structured taste panels. Objective measurements have been made traditionally by texture analysis methods using the classic “Warner-Bratzler” (WB) shear force technique.
The texture analyser is equipped with a Warner-Bratzler fixture to measure the force required to shear through a uniform piece of meat. The Warner-Bratzler jig consists of a rigid frame supporting a shear bar. Interchangeable blades fit into the frame. For meat testing, a triangular slotted blade is used. Sample steaks are cooked, cooled and then 6 core samples (12.7 mm diameter) taken, parallel to the longitudinal orientation of the muscle fibers. The force to shear each core sample using the slotted blade in compression mode is then measured by recording the resistance of the meat to shearing as a function of time in a force-deformation plot. The maximum shear force is the highest peak of this curve.
A different method of shear force testing was developed and introduced in 1992. The system consists of a texture analyser, TA1 equipped with a custom-designed accessory, featuring a flat, blunt-end blade. The resistance of the meat to shearing as a function of time is recorded and displayed automatically using the versatile NEXYGENPlus control and measurement software in a force-deformation plot. The maximum shear force is the highest peak of this curve. The test involves making a measurement on a single 50 mm by 10 mm meat sample cut orthogonal to muscle fiber orientation following cooking. Unlike the WB method, it only requires one measurement per sample, and it can be done immediately post-cooking. Slice shear force can therefore be measured much quicker than Warner-Bratzler shear force because the meat does not need to be cooled before testing and only one slice is needed instead of six cores. The measurement can be completed in less than 10 minutes, which has significant benefits in commercial applications. In addition, it is easier to get one good slice than it is to get six good uniform diameter cores.
The TA1 can be equipped with Volodkevich bite set, for example, consists of stainless steel probe shaped like an incisor that provides results that correlate well with meat toughness. Firmness of canned and re-formed meat can be tested using a Kramer shear cell, which records the force required to shear the sample using five or ten blades simultaneously.