Irish Scientists Study Molecular Signatures in Tissue Associated with Beef Quality

The benefits of advances in understanding of the human genome have helped scientists in their understanding of the cattle and pig genome. There is now a growing realisation that the molecular basis underpinning beef and pork quality is highly complex, Dr Anne Maria Mullen, Head of the Meat Technology Department at Teagasc's Ashtown Food Research Centre, told the 52nd International Meat Science and Technology Conference in Dublin today (Monday, 14 August, 2006).

Dr Mullen, who has led a team of scientists researching meat quality through the application of genomic and proteomic approaches, said that a lot of progress had been made in our understanding of the biological processes that contribute to the delivery of consistent quality meat. "Through the application of genomics and proteomics, we are gaining a deeper insight into these processes and their interaction with environmental factors. Knowledge gained from these approaches can be beneficial in defining and optimising management systems for quality, providing assurance of meat quality and in tailoring quality to suit market needs," she said.

Flavour, tenderness and juiciness appeared to be the three most important things that determined enjoyment of beef. While there have been many successful efforts at improving the tenderness of beef, research has shown that an unacceptable level of variability still remains in beef tenderness. And while there is considerable emphasis on the way animals are fed, managed, slaughtered and both carcass handling and processing post-slaughter, there needs to be stronger emphasis on the molecular or biological components of meat quality.

"What meat researchers are interested in is studying the molecular component of the tissue and seeing how it relates to meat quality. There is still a lot of variability in quality - quality can refer to palatability (tenderness, flavour etc), the health status of meat or technological factors of interest to the processing industry, such as exudate (drip) loss, reduction in yield," she explained.

"Some advances have been made - more technological advances - to try to improve the quality status, but variability still exists. We need to understand the molecular bases that underlie quality to optimize management systems to deliver consistency in meat quality." For too long we have been looking at quantity, not quality, in terms of beef production. "In Ashtown, we are testing the Meat Standard Australia (MSA) model which predicts consumer palatability scores for individual cuts of beef. We hope to feed our molecular information into that model to increase the number of animals that reach market specifications for quality," she said.

Dr Mullen said that a lot of researchers had been looking at the differential protein expression in different groups of animals fed different diets, with different muscle types, foetal development, growth rates and how these factors impacted on meat quality.

In Ireland, scientists are particularly interested in identifying molecular signatures (gene, protein etc) in tissue associated with quality. Understanding how those signatures interact with external stimuli - production or processing - will aid the optimisation of management systems.

"We have gained great insights through investigating single proteins or single pathways within the muscle cell. However, we now need to adopt a more holistic approach to understanding how cellular processes interact within an organism, in response to environmental factors and in the delivery of consistent quality meat. Knowledge gained will benefit scientists and industry alike. Incorporation of this data into a beef management system such as MSA will assist in defining management systems which are designed for genotype," she concluded.