The Accidental Scientist: Science of Cooking Exploratorium
Candy Bread Eggs Pickles Meat Seasoning


Most of meat's flavor develops when it is cooked. The amount of fat in meat influences its flavor, as does a process called the Maillard reaction. Flavor can also be added to meat through brining and marinating.

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Alanine, a simple amino acid

  The Maillard reaction occurs when the denatured proteins on the surface of the meat recombine with the sugars present. The combination creates the "meaty" flavor and changes the color. For this reason, it is also called the browning reaction. The Maillard reaction occurs most readily at around 300° F to 500° F. When meat is cooked, the outside reaches a higher temperature than the inside, triggering the Maillard reaction and creating the strongest flavors on the surface. In the early twentieth century, Louis-Camille Maillard happened upon what came to be known as the Maillard reaction when he was trying to figure out how amino acids linked up to form proteins. He discovered that when he heated sugars and amino acids together, the mixture slowly turned brown.
     

A glucose molecule

  But it was not until the 1940s that people noticed a connection between the browning reaction and flavor. World War II soldiers were complaining about their powdered eggs turning brown and developing unappealing flavors. After many studies done in laboratories, scientists figured out that the unappetizing tastes were coming from the browning reaction. Even though the eggs were stored at room temperature, the concentration of amino acids and sugars in the dehydrated mix was high enough to produce a reaction. Most of the research done in the 1940s and 1950s centered around preventing this reaction. Eventually, however, scientists discovered the role the Maillard reaction plays in creating flavors and aromas. For example, as many as six hundred components have been identified in the aroma of beef.

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Osmosis occurs when water flows from a lower concentration of a solution to a higher concentration through a semipermeable membrane.

Marinades are usually made up of three components: acid, oil, and herbs. The acid helps to partially denature the meat's proteins, opening up "tunnels" in the meat structure where flavor can seep in. But marinades mostly penetrate only the surface. Marinades work best on meats such as chicken breast and fish, because the muscle structure is not as dense as it is in steak. For denser meat, marinades work best when the meat is cut into smaller pieces so the marinade can penetrate a larger surface area. However, if marinades are left on too long, the acids can "cook" the surface, causing the meat to dry out. Some meats, such as pork and steak, can marinate for hours. Other less dense cuts of meat, such as chicken breast and most fish, only need to stay in a marinade for a short time.

Brining meat (that is, putting meat into a salt-water solution) adds moisture to the meat through osmosis. Osmosis happens when water flows from a lower concentration of a solution to a higher concentration through a semipermeable membrane. In meat, this membrane is the plasma membrane that surrounds the individual cells. When meat is placed in a brine, the meat's cell fluids are less concentrated than the salt water in the brining solution. Water flows out of the cells in the meat and salt flows in. The salt then dissolves some of the fiber proteins, and the meat's cell fluids become more concentrated, thus drawing water back in. Brining adds salt and water to the cells so that when the meat is cooked and water is squeezed out, there is still water left in the cells because water was added before cooking.

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Fat, an energy source stored in animal muscles, also contributes to the flavor of meat. Water is the most prevalent component of meat, and most of the flavor-carrying, or aroma, molecules are hydrophobic (repelled by water). These molecules dissolve in fat.

Meat's fat content varies from animal to animal, and within each animal, it varies from part to part. Muscles that are used often consume the stored-up fat, and so the meat from these areas don't have much fat. Areas that aren't used as much don't use as much energy, so there is more fat in these cuts. The animal's age also plays a role in how much fat is in the meat. The older the animal, the more time it has had to build up fat-pocket energy reserves in its muscles.

 


Cattle that are bred for consumption are often fed large amounts of food in order to increase the amount of fat that normally occurs. The more fat in a piece of beef, the more "marbled" its appearance; that is, the more white streaks of fat there are. Marbled steaks are considered to be some of the most flavorful beef cuts.

     
 


As a result of the health risks that may be associated with consuming too much red meat, pork is now a popular alternative to beef. Pigs that are slaughtered are, for the most part, fairly young, and their muscles haven't built up energy reserves. There are some pork cuts that are naturally fatty, such as bacon, but breeders are now using techniques to produce leaner pork. The result is that many pork cuts now have about the same amount of fat as the white meat in chicken.

     
 


With fish, it's a different story. The fat in fish comes from the oils distributed throughout their flesh; it isn't stored in pockets as it is in beef and pork. These oils have subtle flavors in and of themselves, and they contribute to the flavor of the fish.

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See how fat, collagen, and muscle type affect the tenderness and juciness of meat.

See What Meat is Made Of?

 

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