Browning your meat – The science
The science of browning your meat-
Cooking is chemistry; some chef’s might try and convince you that it is magic, but with a basic understanding of the processes involved, it is easy to lift the curtain and peek inside that ‘magic’.
One of the main scientific processes involved in most of the cooking we do here at Scoff’s-Up, is the ‘Maillard Reaction‘.
This is the non-enzymatic chemical processes involved in turning your meat brown when you cook it and filling your nose with those amazing aromas, not to mention improving the taste!
The browning of meat during cooking is fundamental (in most cases) for creating a few things; amazing aromas to stimulate and start the pre-digestive processes in the body, the appealing colour to send safe-to-eat messages to the brain and the chemical change in molecules near the surface of the meat; changes which create the different flavours we crave.
Named after the French chemist, Lois-Camille Maillard, who investigated what happens to amino acids and sugars under the application of heat in 1912, the reaction is one of the underpinning processes of modern cooking.
Nevertheless, it is not the only reaction that takes place; caramelisation for example, can create similar flavours and looks, but undergoes a different chemical process. It is not uncommon however, for both reactions to take place at the same time.
Heat and moisture
So what happens during the browning process then?
Well, now it starts to get heavy.
The process itself is the changing simultaneous chemical reactions that occur when heat is applied to the proteins and sugars in the meat.
It is generally agreed that the heat component needs to be above about 140 degrees Celsius. This is one of the reasons why meat which is boiled or cooked sous vide doesn’t brown. The water and therefore the meat never gets hot enough to kickstart the chemical reaction.
And speaking of water, the higher the water content in the meat, the more it removes energy from the reaction. This is because the energy is used to turn the water into steam.
Therefore, the lower the water content, the more energy that is available for the reaction. (This can be witnessed if you put too much meat in a pan when searing it, the water content leaves the meat and it boils rather than sears, leaving the meat grey rather than brown).
It is therefore advisable to dehydrate the surface before searing.
This can be done by adding salt the meat.
The salt draws out the moisture from the meat via osmosis, which can then be patted dry.
So what actually happens?
Before searing, there are long chains of amino acids which form the proteins in the raw meat. Some of these structures are susceptible to the ‘Maillard’ process and some are not.
Proteins that are susceptible have a preference to bond with the natural sugars present in the meat.
They react with the carbohydrates to form an unstable intermediary structure, before bonding with smaller simple sugars called ‘reducing sugars’ such as fructose and glucose. These reducing sugars react with the amino acids at a certain temperature and moisture levels.
Therefore, as the surface of the meat is exposed to the high temperatures during searing, it dehydrates and the reaction begins, with the very simple sugars and protein chains forming new, slightly more complex molecules. In turn, these now undergo change with more proteins and sugars, each new molecule becoming more and more complex. These denatured proteins form ring shapes which reflect light differently from their previous chain form, causing the meat to look brown.
However, it is not just colour these proteins alter; because of their new shape, the new compounds attach to different smell and taste receptors in our nose and this in turn fires a different signal to our brain. This is the ‘smell’ and ‘aroma’ created by the reaction. This is why cooked meat tastes different to raw meat, and doesn’t just taste like hot raw meat.
Thiopene compounds for example, contain sulphur and create a meatier quality to the taste.
Alapyridaine compounds contain oxygen and enhance flavours already present, making the meat taste ‘meatier’.
This is also the underpinning science behind how manufacturers can create artificial tastes in some of their products, like beef flavoured crisps.
When in an alkaline environment, this process is accelerated even more. Therefore altering the pH (adding baking powder for example) will improve the taste.
Apply too much heat, or cook it for too long and the process passes through the Maillard reaction and into the Pyrolysis reaction, which creates burnt smells and bitter tastes.
So is browning your meat important before cooking it?
Most of the time, almost certainly, yes.
It is not about sealing in the juices; it is about creating desired flavours, intensifying the flavours and adding a pleasing colour to the meat.