DIFFERENCES IN MUSCLE FIBRE TYPE IN LAMB RELATE TO DIFFERENCES IN COLLAGEN SOLUBILITY AND PERI-NATAL MMP ACTIVITY

LATORRE M. EMILIA; PURSLOW PETER

Cork

Congreso; 63rd International Congress of Meat Science and Technology; 2017

Differences in cooked meat tenderness between muscles are known to be partly due to their intramuscular connective tissue (IMCT) characteristics and may also be due to differences in muscle fibre type composition. The hypothesis that the activity of matrix metalloproteases (MMPs) responsible for IMCT degradation is related to the muscle fibre-type muscle distribution was studied in the present work. The majority of MMP expression within muscle is by the muscle fibres. Lamb gastrocnemius and sternocephalicus muscles showed differences in fibre-type distribution and the heat-solubility of IMCT collagen, and also showed differences in collagenase activity. A correlation of higher collagenase activity and a higher collagenase activity with the proportion of oxidative muscle fibres in the muscles supports the hypothesis that more oxidative muscle fibres tend to express more MMPs. This initial study on two lamb muscles will be extended to more lamb muscles and specific MMP activities to expand knowledge on this relationship.