- This information graphic artwork is part of a series featured in Top Chef Masters “Blinded Me With Science” Episode. (Shots with the art: Video 1, Video 2, Video 3, Video 4, Photos 15-26). Refer to the post Quick & Easy (Food) Science Art! to read about the governing process and all the topics involved.
- I was in charge of the whole design (like being my own client), with a team of scientists for research and advice, though I also did some research and learned everything they threw at me. On this illustration, the scientist mentors were Michael Klopfer (the Maillard Reaction scientist on the show), Kevin Miklaz, and Julia Stewart. Though the schedule only allowed me a few hours to understand the concepts at molecular levels, in this case I had to push it a bit longer!
- This is just a selection of the studies produced, by far not all of them.
- Unless noted otherwise, all quotes are my own, from the discussion with the scientists.
There are a lot of complex things a scientist or engineer takes for granted that not even another scientist or engineer readily knows, if it’s outside her/his field. Science is LARGE! This was the case with the Maillard Reaction. There were probes into why things happen, but in the end it took lots of conversations and learning A LOT of chemistry. I had never heard of the Maillard Reaction before working on this… I imagined it as something French and, because of the word “reaction” and in the context of cooking, involving some heat.
“The most helpful direction I found is from reading in the Curious Cook where it was mentioned that Nitrogen and Sulfur give taste to the C, H, and O. This made me think that it is because you are removing tasteless H + O (water) and recombining the N, S, & C that you get the taste. As Michael said and I put at the top, the purpose is to understand why cooked food tastes better than raw.
So I tried to show this across a temperature graph. The question is, are my assumptions correct. Then, how to proceed from here… I’d like to keep it simpler than showing all the various chemical combinations, or maybe just show one, because it takes time to understand the structure and people will not have time. They will need simple recognizable images/symbols to respond to (refer to other posters). We can show images of the ingredients that undergo this reaction and maybe one example of it at chemical close-up.
In terms of the color, why does it turn brown?”
(Above) In these early sketches I put down notes into the graphic to understand what the reaction is about and what is important to show, because there were still many unknowns. One thing that was hard to establish is at what temperature this reaction takes place and what happens at the various degrees. “Just realized the water loss also makes sense as to why this happens at temperatures above 212 where water evaporates.” “Maybe when it burns it loses taste because you are destroying the tasty N & S and it’s just Carbon?” Different sources quoted different degrees for the Maillard Reaction and there was even an article Kevin found which said it can occur at room temperature. We agreed to use the number from Michael.
The difficulty was that there is no one place on the web that explains the Maillard Reaction thoroughly – typically just the detailed chemistry is shown – and I didn’t have time to read through books. The hours of conversations with Michael opened the topic into many more directions, because it does involve a lot of topics, which made it too large and wide open for the purpose of a simple educational graphic. So I listened, translated, and conducted some of my own research.
“The Amadori rearrangement is begging a role in Ocean’s Fourteen… Looks like a structural plan…”
The issue with the Maillard Reaction is that it requires an understanding of basic biology (of the thing you are cooking) and organic chemistry, together, and also, tangentially, a bit on the human digestive system & nutrition. The Maillard Reaction involves the breakdown and recombination of the molecular structures of water, amino acids (building blocks of protein, which are complex), and sugars, notice the s! The reaction happens at this molecular level with actual atoms moving around and relocating. In order to fully understand it, though, you also need to look at the bigger perspective, the structure that these molecules belong to. The amount of information that this piles up to is too big for a simple illustration.
(Below) The following notes, based on my conversations with Michael (put down several days later, after they settled in my brain and I had time to do some research) served as the basis for the design. Since this topic was so seemingly complicated, it was more efficient to get the explanations through a live conversation rather than in writing back and forth, though Michael did write some long essays.
“To recap for others. Basically the Maillard Reaction takes place where there are enough amino acids and sugar and some water. Water, through hydrolysis (maybe I got this wrong), helps to break down the bonds… so that this reaction can happen at low temperatures as well but it would take forever. If you want cooked food, you need to break bonds and recombine molecules/elements at faster rates. As you can see, baking a meat takes longer than frying it (to produce a Maillard Reaction tasty coating) because of this temperature element. Roasted things best depict the good flavors produced by the Maillard Reaction (meats, coffee, bread crust).
That’s one thing. The other part is that the various flavors that can be produced have to do with the amount of ‘information’/ingredients going in: the more complex and rich the amino acids going in, the more flavors you will get coming out. You can think of it as a kind of reshuffling: the more elements you have to play with the more combinations you can make. This is why chicken tastes different/less than lamb… lamb probably has a more complex amino acid base.
Third, most all food ingredients have both protein (amino acids) and sugars (in the form of glucose which is present in every living cell, or starch or another type of sugar AND the ‘sugary’ twisting sides of the DNA, and also in RNA) which means that this reaction can happen within many food items. It is probably best detected in foods rich in proteins because, again, you have more elements to play with and thus the flavor combinations produced are of a greater variety.”
… followed by an example of how our conversation went a bit far and off (#1), and how chemistry “shorthand” was required to understand the reaction (#2).
A bit more, just to put it all down in writing…
1. Water breaks down table sugar (sucrose/di-saccharide = two sugars) into something we / our body can use (glucose & fructose, the former of which can be used by any cell, the latter of which can only be metabolized in the liver).
For this reason, energy drinks contain glucose. This is also why high-fructose (lots of fructose) is bad for your liver. It puts too much strain on it to metabolize (convert) the sugar.
I actually had this happen while cooking. The sugar wasn’t ‘melting’ into the butter. I intuitively knew water melts sugar so after stirring forever I added just a bit of water and that dissolved the sugar so it could recombine with the butter. There is another sugar called ‘inverted’ sugar that I should have used… for making candy, but this worked!
Here is more on the many types of sugars present.
2. The chemical convention for reading these compound diagrams typically exclude Carbon (and Hydrogen) because they are so prevalent in organic chemistry. So if you see something like this or this it means that at every joint where nothing is written there is a Carbon atom + possibly a Hydrogen atom or more.
A Carbon atom needs to have four atomic bonds in order to be stable. One line that goes to it means one bond. Two lines means two bonds. The third and fourth bonds then are always going to be Hydrogen, which is also not shown.
a. corner with two lines meeting up – not shown = 1 Carbon + 2 Hydrogens.
b. corner with three lines meeting up – not shown = 1 Carbon + 1 Hydrogen.”
Here are really good image descriptions showing how amino acids are formed (that the 20 essential ones have the same structure and parts + one part that is different) and how chains of them form proteins.
You can see how they have polar ends (one positive, one negative) and that when they are added together water is a by-product. The peptide bonds are formed by “dehydration synthesis”… and so more on how hydrolysis breaks them down.
For hydrolysis you need an enzyme. The Maillard Reaction is non-enzymatic and so I understand that heat plays a role instead of the enzyme… when there is no heat I’m not totally sure…
Well… maybe they’re not all polar… that makes it more confusing…
Still trying to figure out how to represent this simply and quickly…”
The color for this design could not have been anything but brown. This attempt (above) included the following ideas:
- The temperature bar across the top showed not only where the Maillard Reaction (the creation of flavors without spices) takes place (in cooking, because under special and time consuming conditions it can also happen at lower temperatures), but also that caramelization, which is sometimes confused with the Maillard Reaction, is a completely different and separate reaction that happens at higher temperatures. “I could take out the fact that it can also happen at smaller temperatures. I put rot there because since it takes days to occur, I assume the food would rot. But the idea is it can also happen at smaller temps.”
- Under that, the baked meat on the left and fried meat on the right showed that the Maillard Reaction happens on the outer layers only (because the heat required is at the right temperature on the outer layers, but lower inside), and so the inside remains flavorless (from the M.R. perspective). The food examples to the right of those correspondingly showed what happens at higher temperatures, for comparison and fuller understanding.
- Farther down, sort of like “zoomed out” of the center, the reaction was broken up into details, showing what is required for it to occur: 1. Protein (shown as a chain of amino acids) plus 2. Sugars (shown where they are found in living cells, because there is no need to “add” any sugar) plus 3. water (also internal to the living cells, not added) plus 4. heat = a bunch of molecular recombinations that we call flavors, plus the color brown. “It’s not just the protein +… that’s important… also the sugar is not an added sugar and it’s not table sugar. The cells already have it in there. That’s another important point. I’m gonna say (mono)sugar so people quickly see a difference… It’s actually a reducing sugar… maybe I should put reducing in there… I don’t want someone to think you are ADDING sugar… that’s a big point. Or ‘internal’ sugar… the water is internal too… You’re not putting them in water! Just adding heat.”
- Along the bottom the idea was to show the amino acids in the two examples (those are just placeholders), and how they are recombined to make a certain number of flavors. “We could say ‘few flavors’ next to the caramelized onions and ‘lots of flavor’ next to the beef. The thing is, we don’t have space to show all the exact various combinations and they are so detailed as molecular compounds that they’d make people dizzy… In the blank top left area I can show the basic parts of an amino acid and how they differ from one another.”
(Above) In the development of the illustration, some elements were added and others subtracted to clarify the story:
- The cooking examples were drawn more realistically and used only for the Maillard Reaction.
- The molecules were drawn in detail, showing every atom. This was important to do because the reaction is about the actual atoms moving around and regrouping to create new (flavor) molecules. I researched all the atom sizes (their diameters actually vary because the electron cloud is in motion or so) and drew them to the dimensions most agreed upon/the average. “Whenever you look up the Maillard Reaction, even in cooking forums, you see the molecules, so I thought necessary to put them.”
- I used the standard color conventions for the atoms (probably the only time I will use pure black in an illustration). White = Hydrogen. Red = Oxygen. Blue = Nitrogen. Black = Carbon. Yellow = Sulfur.
- At Michael’s suggestion to use onions as an example, I put just two of the amino acids he said were more important to onions (leucine & cysteine), because all of them wouldn’t fit. In terms of the sugars, the ones shown are: xylose (plant specific), glucose and ribose. Kevin, who does a bit of home brewing, explained how it works in beer, but that didn’t make the general audience cut. Julia suggested that: “Self-tanners also use the M. Reaction!” And I thought of a new phrase you can use at your local coffee shop: “If your coffee tastes burned, you can say to the roasters ‘Please stop at the Maillard reaction.'”
- Also of note, the symbol for the sugar was changed to a pentagon, as that is how it is often represented (for the sugars with five carbons). In chemistry, the sugar molecule is depicted two ways: as a chain or as a ring. Here I show it as a chain because it fits better. “FYI for your curiosity (and mine) since there won’t be space for it in detail: the sugar in DNA [the pentagon]“.
From then on (above), using the onion example, I drew the different flavor molecules that are produced by the Maillard Reaction in browned (popularly mislabled as caramelized) onions. You can see that sulfur (the yellow atom) is in almost all of them (for onions). It took some time to draw them, because I was looking at chemistry shorthand drawings, just lines with the occasional S or O letters in place, but with the Carbon and Hydrogen atoms’ locations/presence left to be interpreted.
As the molecules were quite detailed and seemingly too small, the content was “re-shuffled” to give them more prominence and visibility (above). Instead of putting the heat as an ingredient, I simply showed it “under,” as if it’s cooking. The graphic reads from left to right: ingredients over fire make flavors.
Developing it a bit more (above), I tried to organize it in a way in which you can see where each piece comes from in the actual food: from the onion strand, to the cell, to the protein chain or DNA, to the amino acid or sugar, etc.
In the final design (above), the drawing was cleaned up a bit, colors improved, and, to reduce an overwhelming amount of information, the amino acid protein chain and the DNA were removed, using simple arrows to show where the molecules are found in the cell.
I also changed the leucine amino acid for methionine, because it has sulfur and would make a better case for all the sulfur in the flavor molecules; added bread as another example up top; put a legend for identifying the atom types; and since Monsieur Maillard’s handsome portrait couldn’t, for copyright reasons, be present, added a bit about his discovery. History is just as important as science!
So, from this, what can one understand about the Maillard Reaction?
To summarize it from the perspective of the illustration, the Maillard Reaction describes how the atoms of protein, sugar and water molecules (ALL ALREADY PRESENT in the (cells of the) food you are cooking), heated around 250-300F, regroup into (new) flavor molecules. Through the Maillard Reaction, food containing protein, heated the right amount, turns brown and becomes flavorful (separate of adding spices). The reaction is stronger and produces more pronounced flavors in meat and nuts than in vegetables or cereals because of the higher presence of amino acids (more protein). Basically, it’s why roasts are delicious!
“I think bacon must be total Maillard Reaction and that’s why it tastes so good (also fat + salt).”
The reaction generally only occurs along the surface of foods because the interior will typically have a lower temperature.
How this happens – through a non-enzymatic reaction, through hydrolysis – couldn’t fit in this “picture.” But if you’d like to know what that means… non-enzymatic means without enzymes. In your stomach, you break down the amino acid protein chain using enzymes. In the Maillard Reaction, there are no enzymes, and so it takes heat, and water (hydrolysis), to break down the amino acid protein chain.
For cooking, the Maillard Reaction is about how flavors (and browning) are created in foods with protein.