Small Heat Shock Proteins in Meat Tenderness11 November 2013
The continuing challenge for the red meat industry is to produce high value cuts of consistent good quality.
The eating quality of meat is a result of complex interactions between the biological traits and biochemical processes that occur post-mortem as muscle is converted to meat and during storage.
But for the consumer, there are three dominant meat attributes by which they judge meat quality -appearance, tenderness and flavour, according to a study by the Ruakura Research Centre and AUT University in New Zealand and Svenska Samernas Riksförbund in Sweden.
How these attributes meet the consumers' expectations is critical and deviating from this will adversely affect the meat's marketability.
Although much work has been undertaken to optimise meat quality and minimise variability, the causes of large variation in meat quality is still not fully understood.
Recognising the fundamental importance of muscle proteins to meat quality attributes, there has been a growing interest on how muscle proteins and the genes regulating their expression relate to meat quality.
Proteomics is a tool increasingly used by meat scientists to determine the protein profile of muscle earlypost-mortem and during storage. Proteomics is the characterisation of the entire complements of proteins (proteome) that are expressed in a cell or tissue type.
Determination of the proteome of a muscle provides clues on the function of genes and reveals a better understanding on how biochemical processes taking place in muscle affect meat quality.
The majority of proteomic studies in meat science have aimed to determine the proteome of muscle to identify molecular markers, or biomarkers, for meat quality traits.
Several of these studies have consistently reported the differential expression of chaperone proteins, specifically small heat shock proteins, in muscle with variable tenderness, colour, water holding capacity and flavour.
In the research by D. Lomiwes, M.M. Farouk, E. Wiklund and O.A. Young, it was hypothesised that muscles inevitably engage towards apoptotic cell death due to the termination of oxygen and nutrient supply to the muscle following exsanguination.
Thus, factors that regulate the process of apoptotic cell death of muscle cells are believed to ultimately influence meat quality.
Proteomic studies have associated the regulation of small heat shock proteins (sHSPs) with various meat quality attributes including tenderness, colour, juiciness and flavour.
The researchers said that they saw increasing evidence for the role of sHSPs in meat quality, particularly meat tenderness, has been reviewed.
Due to the anti-apoptotic and chaperone functions of sHSPs, they are proposed to be involved with the eating quality of meat.
The research team said there was a possible chaperone and anti-apoptotic role of sHSPs during the conversion of muscle to meat and the team considered the repercussions of this on the development of meat tenderness.
The researchers added that the expression of sHSP which are up-regulated during periods of stress as indicated by pH, may explain the high variability of quality attributes in meat.
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