Where the flavor in food comes from

How chemists make things taste delicious

Original photo [Depositphotos]

The taste of the av­er­age ap­ple is de­ter­mined by 29 dif­fer­ent sub­stances, while a de­cent cup of cof­fee is made up of around 100.

The pro­fes­sion of fla­vorist ap­peared quite re­cent­ly, when freez­ers be­came com­mon in al­most ev­ery home, and food had to pre­serve its taste even af­ter long freez­ing. A fla­vorist is a chemist who ad­justs and mod­i­fies the fla­vor and aro­ma of food. Al­though most of the train­ing takes place in prac­tice, a novice fla­vorist is helped con­sid­er­ably by an ed­u­ca­tion in chem­istry, and es­pe­cial­ly by a knowl­edge of or­gan­ic chem­istry.


Freez­ers be­come more avail­able

Fla­vorists say that any fla­vor has three key com­po­nents:

  • a char­ac­ter item — this main­ly de­ter­mines what the prod­uct is by its fla­vor and aro­ma;

  • a con­trib­u­to­ry item — this in­ten­si­fies the main leit­mo­tif (even if in it­self it is some­thing very re­mote from it);

  • a dif­fer­en­tial item — this may not seem to be sig­nif­i­cant, but it can add some­thing very char­ac­ter­is­tic to the main fla­vor.

Be­fore they cre­ate a cer­tain fla­vor, chemists study its nat­u­ral pro­to­types. They use sev­er­al meth­ods: from or­di­nary dis­til­la­tion to more hi-tech spec­troscopy, tak­ing into ac­count dif­fer­ences in the be­hav­ior of var­i­ous chem­i­cal bonds when they are hit by in­frared and ul­tra­vi­o­let light, and chro­matog­ra­phy, which de­tects the com­po­nents of com­plex mix­tures. All of this helps to find an im­pres­sive amount of sub­stances, which de­ter­mine tastes and aro­mas. Now you’d think that all you have to do is to mix the right mol­e­cules in the right pro­por­tion to get the ide­al fla­vor. But alas, na­ture is more com­pli­cat­ed than that: no one has been able to put to­geth­er the 29 com­po­nents of the fla­vor of an ap­ple in the same way that the ap­ple does it­self. Per­haps this is be­cause the tests have yet to be per­fect­ed, and omit some im­por­tant de­tails which are dif­fi­cult to no­tice. Nev­er­the­less, there are some taste for­mu­las that have been dis­cov­ered.

Fried meat [Depositphotos]

The fla­vor of fried meat, for ex­am­ple

The sub­stances that give meat its main, crisp aro­ma, are cre­at­ed dur­ing its ther­mal pro­cess­ing, in a chem­i­cal re­ac­tion known as the Mail­lard re­ac­tion. This takes place as fol­lows: meat has many pro­teins, which in their turn con­sist of amino acids. When these amino acids re­act with sug­ar when sub­ject­ed to heat, a sub­stance called gly­co­sy­lamine is formed. En­ter­ing into fur­ther re­ac­tions with its en­vi­ron­ment, the gly­co­sy­lamine forms sub­stances which pro­vide a char­ac­ter­is­tic fla­vor. And if you know the set of these sub­stances, you can sim­ple add them to food to give it the aro­ma of fried meat.

Here, for ex­am­ple, is a sure-fire chem­i­cal recipe for “fried pork”:

  • 2-methyl-3-fu­ran­thi­ol — the “char­ac­ter item" (gives the main meat fla­vor);

  • piridinemethanol — the “con­trib­u­to­ry item” (adds pork nu­ances);

  • butyl-2-de­canoate — the “dif­fer­en­tial item” (makes the fla­vor “more fat­ty”).

Mix un­til you get the de­sired fla­vor.

Things are more com­pli­cat­ed with cher­ry yo­ghurt.

If you like cher­ries, but hate food “with cher­ry fla­vor”, this is quite un­der­stand­able. It’s hard to ac­cept that the ar­ti­fi­cial cher­ry fla­vor has so lit­tle in com­mon with ac­tu­al cher­ries.

maraschino cherries [Depositphotos]

The prob­lem is that mod­ern cher­ry fla­vor sub­sti­tutes im­i­tate the fla­vor of maraschi­no cher­ries. They are bright red cher­ries, which are pre­served and sweet­ened (usu­al­ly they are used to dec­o­rate cakes or cock­tails). And as a stan­dard of fla­vor, maraschi­no cher­ries are the most suit­able, un­for­tu­nate­ly, as the nat­u­ral fla­vor of most types of cher­ries is weak, and when it is in­ten­si­fied it be­comes very un­pleas­ant.

The syn­thet­ic for­mu­la of cher­ry fla­vor was first pub­lished in 1917 and in­volved a whole chain of var­i­ous chem­i­cals:

  • ethyl ac­etate — a type of chem­i­cal called an es­ter, with a fruity aro­ma and which is found, for ex­am­ple, in nail-pol­ish re­mover;

  • ethyl ben­zoate — a col­or­less liq­uid, an es­ter with an aro­ma sim­i­lar to mint;

  • apri­cot oil — squeezed from the cores of apri­cots or sim­i­lar fruits;

  • ben­zoic acid — a type of car­bon­ic acid, which is also used as a preser­va­tive in var­i­ous foods (in the list of in­gre­di­ents it will be proud­ly named “E210”);

  • glyc­er­ine – a sweet­ish liq­uid used in pre­par­ing low-calo­rie food;

  • ethyl al­co­hol – just what it says.

To­day the main com­po­nent of cher­ry fla­vor sub­sti­tutes, ben­zalde­hyde, is a sub­stance with a pleas­ant aro­ma of al­monds.

Citrus [Depositphotos]

A few words about cit­rus and pine

The aro­ma of lemon, or­ange and pine is pro­vid­ed by the same sub­stance - limonene. The “cit­rus” and “pine” ver­sions of limonene con­sist of iden­ti­cal atoms bond­ed to­geth­er in an iden­ti­cal or­der. But the mol­e­cules are a mir­ror re­flec­tion of each oth­er - enan­tiomers. And this small de­tail is suf­fi­cient for us to sense these aro­mas dif­fer­ent­ly.

Na­ture has many more se­crets. But sci­ence doesn’t stand still ei­ther. Per­haps we will soon tru­ly en­joy the fla­vor of cher­ry yo­ghurt. And maybe even ap­ple yo­ghurt.

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