The taste of bacon

No smell is as alluring as that of a sizzling piece of bacon while it fries and pops in its own fat; this presents a stark contrast to our perception of  raw bacon, which we see as a slimy piece of animal tissue. What is it about cooking that makes some foods so appealing to our primitive senses? It all boils down to the chemistry of proteins, fats, and sugars at high temperatures. The foods that smell and taste best when cooked are mainly composed of protein, fat and sugar – this is why you can smell chocolate cake or short ribs on the breeze while easily ignoring those steamed peas.

From mythology to modern science, the greatest turning point in the evolution of humans has always been considered as our mastery over fire. “What’s for dinner?” has always been the next natural question. As flippant as it seems, why humans began cooking food and why we prefer cooked food is still a point of scientific contention.

This inquiry has led to some bizarre science and zany experiments. Given the interest that industrial food companies have in tastes, ample money has been committed to answering just why we as humans like cooked food so much.

Naturally, scientists first asked whether we are unique in our preferences for cooked food. To do this, they sat 15 chimpanzees down in a room and gave them the choice between raw or cooked vegetables. The Chimps mostly preferred the cooked vegetables with a few exceptions. Next, they were given a choice between raw and cooked beef. Even though they had never eaten meat before, they went ‘ape-crazy’ over the cooked meat, scientifically speaking.

This experiment proves that humans are not unique in our preferences, but it does not prove why. Some theorize that cooked food appeals more because it is easier to digest and prevents food poisoning. On the other hand, most food chemists support a more hedonistic view – we prefer cooked foods because they smell and taste better.

What is it that makes a taste or a smell? This is actually an incredibly complex question which has given birth to an entire field of chemistry known as headspace micro-extraction gas chromatography-coupled mass spectrometry. Scientists in this field have characterized a multitude of aromatic flavors – most are nitrogenous or sulfur-containing compounds such as pyrones, furans, pyrroles, pyrazines and furfurals. Some of these smells result when the fats degrade into small volatile compounds which become gaseous, yielding the bacon smell. More complex smells are the result of the Maillard Reaction and Amadori rearrangement. In these reactions, a sugar reacts with a protein to give a complex spectrum of decay products which impart the charred taste to meats or the rich taste to maple syrup.

By putting a human on the other end of the detection device, researchers can also figure out which one of these smells we find most appealing. Using this information, scientists have discovered why we choose iberian ham or wild boar over domestic swine. They have also discovered that meats with higher salt content smell better due to a “salting-out effect“. In fact, science has even gone so far as to quantify the “tastes like chicken” phenomenon. By analyzing the chemical headspace of cooked bull-frog legs, they found that frog legs have less sugar and sulfur, leading to fewer Maillard products and more of the ‘chicken’ taste.

Despite all of this incredibly thorough quantification, the science world still does not know why we have receptors or preferences for these smells. Was it just lucky chance that we can immensely enjoy the smell and taste of fresh-cooked bacon in the morning?

For the downsides to bacon and the cancer risks of meats, check out the coming post.

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