and he tends to have muscle of the red sort.
· The connective tissue: The muscle tissue is found surrounded by connective tissue, which
acts as a glue to stick the muscles to the bones and also limits the proteins responsible for
muscle contraction. The connective tissue is composed of strong fibres made mainly of the
proteins collagen and elastin. Collagen is a stiff protein, composed of three long chains twisted
round each other like a rope. The presence of large amounts of collagen tissue in a piece of
meat makes the meat tough. Equally, the connective tissue thickens and toughens as an
animal gets older, increasing meat toughness. Fortunately, the major protein in the connective
tissue, collagen, can be partly dissolved on cooking at temperatures over 55°C to form
gelatine, which helps to tenderise the meat. Elastin however does not tenderise on cooking,
but actually shrinks and hardens. It therefore needs to be removed from the meat before the
meat is cooked, usually by cutting it out with a sharp knife.
· The fat tissue: Between these two tissue types is the fat tissue – the fat tissue is seen as
dispersed white patches in the muscle tissue. Young animals tend to have smaller amounts of
fat in their meat than older animals. The fat tissue will melt on cooking, lubricating the muscle
fibres, making it easier to chew between them. The fat tissue has an important role on the
taste, since most of the aromas in meat are hydrophobic, so are dissolved in the fat part.
Raw meat is therefore not very tender, especially when taken from older animals, or from muscles that
are used often, due to the strong muscle fibres and the tough collagen fibres.
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Meat can also to an extent be tenderised by heating – long heating causes breakdown of the tough
collagen tissue and the melting of the fat that lubricates the strong muscle fibres. However, heating
also causes the meat proteins to denature and coagulate, and long cooking times at high temperature
will cause this network to tighten, and the meat to squeeze out some of its juices making the meat dry.