Rapid and simple poultry tenderness measurement

One of the most common issues facing the meat and poultry industries today is an increase in the incidence of tough meat. 

This problem seems to stem from higher consumer demand for increasingly processed products, which in turn forces producers to increase production. To keep pace with market demand, processors have had to evaluate various means of increasing production of boneless meat without negatively affecting overall consumer acceptance. 

Many processing factors are known today to affect the overall tenderness of broiler breast fillets. Tenderness is the most predominant determinant of quality and has been described as the most important sensory characteristic of meat thereby having the greatest impact on consumer acceptability. The need to ensure consumer acceptance and the increased recognition of the importance of tenderness has led to the development of instrumental methods for monitoring meat tenderness.

Numerous instrumental procedures have been developed for the assessment of meat tenderness since the late 20s because tenderness plays a major role in consumer palatability of meat products. Ideally, the tenderness of cooked meat is assessed by sensory evaluation means because it is a sensory attribute perceived by humans. However, the fact that sensory evaluation is costly, extensive and excessively time-consuming has led to the development of instrumental approaches for estimating meat tenderness perception.

To date, a great deal of effort has been devoted to the development of such instrumental methods. As a result, many methods exist for measuring tenderness of broiler breast meat.  Instrumental methods such as the Allo-Kramer “shear compression system (multiple blade)” and Warner-Bratzler Shear Blade are commonly used within the poultry industry for evaluating tenderness in aging broiler breast meat and the effect of deboning. Descriptive sensory analysis is a method that researchers commonly use for assessing attributes related to the tenderness of poultry meat. These types of test are very reliable and have been shown to be correlated with instrumental analyses; however, they can be extensive and exceedingly time-consuming.

Of the existing instrumental methods for measuring meat tenderness, the Meullenet-Owens Razor Shear (MORS) is the most recently introduced from research carried out at the University of Arkansas and has been established as a reliable predictor of poultry tenderness. The method has gained in popularity because of its high reliability as well as simplicity compared with that of other industry standards (Warner-Bratzler shear or Allo-Kramer shear). The method uses a razor blade of defined dimensions attached to a TA.XTplus Texture Analyser which then performs a cutting/shearing test. Tests are performed on intact fillets using the MORS blade penetrating to a depth of 20mm providing a far less destructive method as only a small incision is made in the sample. 

When performing cutting/shearing tests the consistent sharpness of the blade is always a consideration or cause for concern. The benefit of performing tests using a readily available craft knife blade (such as that shown) is that the blade can be removed and replaced after each test or an agreed number of tests, assuring edge sharpness and therefore increasing the repeatability of the results.

It is recommended that the sharp blade is replaced every 100 measurements for optimum shearing performance and hence result repeatability.

The MORS is not only as reliable as the industry standards and claims to exhibit a higher correlation to sensory attributes than the Allo-Kramer Shear method, but also more rapid because of the elimination of the sample cutting steps. It has been reported that both the WB and AK shear are significantly affected by sample dimensions. Furthermore, AK shear is so dependent on sample dimensions that it is a standard practise to divide the AK maximum shear force by the sample weight.

The razor blade test has proven to also be less time consuming, as 60 measurements can be performed in 1 hour compared with 30 measurements in the same amount of time for the Allo-Kramer shear test. Measured forces are also substantially lower than those produced with a Kramer Shear test, thereby allowing testing on a TA.XTplus Texture Analyser.

Be at the cutting edge of poultry tenderness measurement
Tests using the MORS blade are conducted on whole intact fillets which minimises the experimental errors attributable to sample preparations, shortens sample preparation time and leads to a simpler testing solution. The application of the MORS method will thereby provide advantages over existing industry standards for poultry breast meat tenderness and be of benefit to the poultry industry as it could significantly save labour, time and expertise to implement for routine quality control.

Razor blade shear energy (N*mm) is calculated as the area under the force deformation curve from the beginning to the end of the test and maximum shear force (N) is also recorded during the test. Both parameters used as instrumental assessments of meat tenderness.

Results show that the optimal number of replications of the MORS for a reliable estimate of tenderness to be four shears or greater per fillet in predetermined shearing locations.