When going to the market to purchase fresh beef, you notice that you are faced with different colours of beef. This is more common with road side vendors or those meat vendors in our local market. Most times the colour of fresh beef can be a total turnoff to you when making a choice in the market. People tend to go for beef with a red colour more often. There is a scientific explanation about the varieties of fresh beef colour you find in the market. Knowing this priceless information will help you make the right choice of beef when next you visit the market.
Beef is another name for cow meat. The optimum surface colour of fresh beef is usually cherry-red, but other colour variations are seen, colours like purple red and brownish-red. Note that colour variations is not an indication of spoilage.
Colour Variation As A Result of Myoglobin
- Purple red colour : This colour is possessed by a beef that has not been exposed to air. The purple red colour is as a result of the myoglobin in the meat muscles and when myoglobin is exposed to air, it changes to oxymyoglobin, which gives meat a pleasing cherry-red colour.
- Cherry-red colour : The cherry-red colour is the optimum colour of fresh beef sold in the market. This colour is highly unstable and short-lived. The colour changes quickly due to many factors like oxygen and myoglobin. To help retain the cherry-red colour of fresh beef, you can use a plastic wrap that allows oxygen to pass through.
- Brownish-red colour: This colour results when meat has been exposed to either store lightings or sunlight for a long period of time. It can also result when the meat has been exposed to oxygen for a long period of time. When this happens, the oxymyoglobin reacts with the oxygen and forms metmyoglobin which is the pigments that gives fresh meat the brownish-red colour.
- Rainbow Colour: A fresh beef can possess many colours, ranging from shiny green to sliver colour, but this does not mean that the meat is spoilt. Fresh meat is made up of different compounds like iron and fat. When light hits the compounds, it can cause the colours to split and cause a rainbow effect.
Colour Variation As A Result of Animal Stress
When the cow is being transfered to the abbatoir for slaughter, there are various factors which can impose stress on the cow. Such factors include, environmental stress, nutritional stress, pre-slaughter stress and other stress factors. This stress factors have a direct effect on the colour and texture of the meat. Stress factors mainly causes fresh beef to have 2 distinct colours which are;
- Pale red Colour: This colour of meat occurs when the cow was subjected to severe anxiety and fright caused by man handling. Also when they engage in fights in their pens few hours before they are slaughtered. All this results in biochemical processes in the muscles. The biochemical processes causes the glycogen in the muscles to break down rapidly and this produces a meat which is pale red in colour. It is important to note that such meat has poor flavour. This meat colour turns people off because it is not appealing to the eye and eventually, the meat becomes a waste.
- Dark red Colour: A meat that is very dark in colour is indicative that the glycogen in the cow muscles were used up before slaughter. The glycogen gets used up during handling, transport and pre-slaughter. Especially when the cows were not fed properly a day before the slaughter. Such dark coloured meats have inferior quality and less pronounced taste. Also, such meats have a shorter shelf life and can spoil faster than normal.
Endeavour to be aware of causes for meat colour variations so you can make the right choice in the market. Remember, a colour change does not necessarily mean that the meat is spoilt.