The Invisible Palatant. By the time the palatant reaches the coating drum, the food already has a smell, a texture and a sensory history. What the animal encounters was being shaped long before the final coating, and no single stage can claim all the credit.
Movement I
BEFORE THE DRUM
Stand at the end of the line in a petfood plant, past the extruder and the dryer, before the coating drum, and stop the belt for a moment. Reach in and take a handful of the kibble as it comes off the dryer. It is warm, dry, pale, finished in shape but not yet in anything else. Nothing has been sprayed on it. Nothing has been dusted over it. The fat, the palatant, the coating the industry thinks of as the flavour, all of that is still waiting a few metres downstream, in the drum the pieces have not yet reached.
Now put the handful to your nose.
It smells of something. Not of nothing, not of a blank pellet waiting to be given a character, but of something already: a warm, toasted, faintly meaty, faintly cereal smell that is unmistakably food. No one sprayed it on. It arose, somewhere back along the line, out of the raw materials and the cooking, and there it sits in your palm, a finished aroma on an unfinished food, before the part of the factory whose whole job is flavour has so much as touched it.
That is the fact this essay begins from, and it is stranger than it first sounds. We have organised much of the business of petfood around a convenient division: the base supplies the nutrition, the coating supplies much of the attraction. It is a useful division of labour, and no one who works in it imagines the base is odourless. But the division shapes how we speak and where we look, and the handful in your hand shows why it is not the whole account of the food. Because the base, before any coating, already smells. It already has a taste waiting in it. It already carries, written into its cooked and dried body, a sensory character the animal will meet whether or not another thing is ever added to it.
The invisible palatant is not something the factory adds. It is what the factory has already done.
Which turns the usual question inside out. We are used to asking what a palatant brings to a food. The handful of naked kibble asks the reverse. If the food already smells of something before the palatant arrives, then what is the palatant arriving at? It is not coating a blank. It is landing on a food that has already been made to smell and taste of something by everything that happened before, and whatever it adds will mix with, lean on, or work against a character that was there first.
And if that is so, a harder question follows, the one this Conversation is really about. When an animal empties one bowl and leaves another, and both foods wore the same coating, we reach by habit for the coating to explain the difference. But the coating was the last thing to happen to either. How much of what the animal was answering to had already been settled upstream, in the cooking, before the drum, before the stage we credit with flavour ever entered the story?
Keep the handful. We are going to follow it back up the line.
Movement II
THE FACTORY IS A KITCHEN
Follow the smell back and it leads where every good smell in a kitchen leads: to heat, and to what heat does to food.
For all its scale and steel, a petfood plant is doing something a cook would recognise. It takes raw materials, meats, grains, fats, and it cooks them. The extruder is an oven and a pan at once, driving heat and pressure through the mix; the dryer finishes the work. And cooking, whether in a pan or in a barrel the length of a room, is not a neutral warming. It is chemistry. The heat sets the food's own components reacting with one another, and out of those reactions come things that were not in the raw mix at all, among them the smells.
The chief of these has a name, though the cook who browns an onion or sears a steak has never needed it. When the amino groups carried by the food's proteins and their smaller building blocks meet reducing sugars under heat, a cascade of reactions begins. Some of what it makes is colour, the browning of a crust; some of it is aroma, the roasted, nutty, meaty and savoury notes we know from cooked food. It is the chemistry of the crust on bread and the sear on a steak, and it is running, at industrial scale, inside the machine that made the handful in your palm. No one reached for a bottle of meaty flavour. The cooking made one, out of the food's own flesh and grain.
The fats take their own part, reacting under heat into notes of their own, some the warm richness a carnivore reads as food, some, pushed too far, the first edge of the rancid. And moisture sits quietly behind all of it, as the last Conversation argued, deciding what can react and how, so that the water in the mix is not a bystander to the cooking but one of the hands shaping what the cooking makes. The point, for now, is only this: by the time the pieces reach the dryer, a great deal of sensory chemistry has already happened, unbidden and unbottled, written into the food by the plain fact that it was cooked.
But there is an awkward question sitting in all this. If the cooking makes the flavour, why might a dog find a piece of raw meat worth crossing a room for, with no cooking at all? Why might a cat approach raw flesh with an interest no coating drum was ever required to produce?
Because the cooking did not begin with nothing. Meat arrives already carrying its own chemistry, its own taste-active substances, its own quiet history of change since the animal it came from died. Heat can release what was bound inside it, transform what was already there, build compounds that did not exist before, and spend some of the signals the animal would otherwise have met.
Cooking is an author of flavour, but not its first author.
So the raw meat corrects something the factory makes easy to forget. The line we have been following back does not stop at the dryer, or even at the raw mix. It runs to the ingredient itself, which arrived already able to taste of something. Processing changes what was already possible; it does not conjure it from nothing.
And here it would be easy to draw exactly the wrong conclusion. If the cooking generates flavour, then surely more cooking, more reaction, more of that brown and savoury chemistry, makes a better food. It does not, and the error is worth naming because it is so tempting. Push the reactions too hard and the roasted turns scorched, the savoury turns acrid and bitter, and the nutrition suffers in the bargain, the building blocks the animal needed spent on compounds no one wanted. A reaction can make a new smell without making a better one. More chemistry is not more palatability; it is only more chemistry.
To generate a flavour compound is not to earn a preference.
Which is the discipline this movement insists on, against its own enthusiasm. It is genuinely remarkable that a food can cook itself a smell. But the machine that generates a thousand new compounds has not thereby chosen the ones an animal wants. Of all that chemistry, which did the dog or the cat actually ask for? We cannot read a preference off a chromatogram. The cooking tells us what was made. It does not tell us what the animal, with its own and different biology, will seek. That verdict was never the factory's to give.
So the handful in your hand is not a blank that flavour will later be added to. It is already the work of a kind of cooking, carrying a character the cooking built and the cooking could just as easily wreck. Which raises the question the next movement turns on. If the base food already has a character of its own, what happens when the coating finally arrives and meets it?
Movement III
THE SUBSTRATE HAS A MEMORY
Now let the pieces reach the drum, and let the coating arrive at last.
In the tidy division of labour, this is the moment flavour is supposed to happen. The fat and the palatant go on here, the same measured amount to every batch, and the industry speaks of the result as though the coating carried its performance within itself, a fixed quantity of palatability poured evenly over whatever passes through. Send the same coating down the line at the same rate and you should, on that picture, get the same food.
You do not, and the reason is the whole of this movement. The coating does not land on a neutral surface. It lands on the food we have just followed out of the kitchen, a food with a structure the cooking gave it, a surface the drying left, and an aroma the reactions already built. The base is not an empty page the coating writes on. It is a page already written, and what the coating becomes depends on what was there to receive it.
Consider only what the structure can do. A piece left more open and porous by its cooking may take the coating in and hold it, releasing it slowly from within, where a denser, more closed piece may carry more of the same coating on its surface, exposed and quicker to give itself up. That is one way a base can shape what the coating delivers, not a rule, and real pieces rarely sort themselves so neatly into kinds. But wherever such a difference runs, the identical spray, the identical amount, becomes a slower, deeper thing on one food and a quicker, brighter one on another. The coating specification alone might not tell them apart. The drum applied the same material to both. The food did not receive it in the same way.
And the aroma the base already carries does not stand politely aside while the coating speaks. The base's smell and the coating's meet, and where they meet the newcomer can be lifted by what was already there, or lost in it, or set against it. A savoury coating laid over a warm, savoury base is not the same event as the same coating laid over one the cooking left flat, or scorched. The coating's contribution is real, but it is never delivered into silence. It is delivered into a sound the food was already making.
A palatant does not carry its performance alone. It performs on the food it is given.
So the thing the industry treats as a fixed property turns out to be a meeting. The result at the bowl is not the base plus the coating, separate quantities laid side by side and summed. It is what the two did to each other, and that cannot be split cleanly back into a share for each. It is the same lesson this series has kept arriving at from every direction, that a signal has no worth on its own, only in the thing that receives it, carried now one step further back, into the food itself: the coating's worth, too, is less its own than it looks, decided in large part by the base that will hold it, release it, or drown it.
Which turns the usual verdict into a question. When a food is emptied and another, wearing the very same coating, is left untouched, we say the coating on the second failed. But did it? Or did it do exactly what it does, on a base that received it differently, so that the thing we blamed last was shaped by the thing we never thought to look at first? The palatant did not underperform in the abstract. It performed, as it always does, on the particular food it was given, and that food had a memory the sheet never recorded.
So before we ask who gets the credit, we have to admit the work cannot be cleanly divided. Which is exactly where the factory's neat departments begin to strain.
Movement IV
WHO GETS THE CREDIT?
A factory runs on division. The thing that lets a plant make tonnes of a complex food is that no one person makes it. The work is cut into parts, and each part is handed to someone who is very good at it.
One company grows and sells the protein, another the fat, another the grains. A process engineer owns the cooking, and knows that machine the way a chef knows a stove. A formulator sets the recipe and its targets. A palatant developer builds the coating and understands, better than anyone else in the chain, how it behaves. These are not naive people. Ask any of them and they will tell you that the parts interact, that the coating depends on the base, that the cooking shapes the smell. The knowledge is there, held in good hands, all along the line.
And yet something gets lost in exactly the seam that makes the whole thing work. Because each of these experts owns a part, and not one of them owns the animal's experience. The dog does not eat the supplier's protein, or the engineer's cooking, or the developer's coating. It eats the single thing all of them made together, and that thing belongs, in the end, to no department.
The factory is divided into departments. The animal is not.
Which makes the simplest question, whose result is it, strangely hard to answer. The last movement showed why the result cannot be split into clean shares, a quantity from the base and a quantity from the coating laid side by side and summed. If the contributions are not separable in the food, they are not separable in the credit either. The animal's verdict is real, but it is a verdict on the whole, and it does not come itemised. It will not tell you how much was the protein, how much the cooking, how much the drum.
So when a food performs, or fails to, the pull is always toward the same answer. We credit, or blame, the coating. Not because anyone believes it acted alone, but because it is the most visible stage and the easiest to change. The ingredients are contracted months ahead, the cooking is fixed in steel, the recipe is signed off. The coating is often among the last levers still available to adjust, and therefore among the first we reach for, so it becomes the stage we change, and in changing it we quietly hand it a responsibility the food never gave it alone.
The last thing added is the first thing blamed.
And there is a sharper turn of the same screw. Processing can remove sensory signals as readily as create them, and not every change will favour the animal's response. Could the coating sometimes be praised for recovering something an earlier stage quietly removed, the last operation credited for repairing the work of one no one examined? The possibility is worth sitting with, even if the share each stage took cannot be read off the finished food.
This is not a charge of ignorance. The specialists understand the interactions better than the essay does. It is a charge against the shape of the thing, against the way a problem that lives in the relationship between stages comes to rest on whichever stage is nearest to hand. The division of labour that makes the factory possible is the same division that scatters the authorship of the result across boundaries, between companies, between departments, between the people who built the base and the people who coated it, so that when the animal turns from the bowl, the cause may sit in a seam no single party was ever asked to watch. Where, then, should the responsibility rest?
That is the uncomfortable place this movement leaves us. The food is a joint work, and the responsibility for how it tastes to the animal is joint too, distributed along a chain that was organised, for every good reason, to be divided. We know how to assign credit to a stage. We are far less practised at assigning it to a relationship.
Which leaves only the one party who never divided anything, and never could: the animal, at the bowl, meeting all of it at once.
Movement V
THE ANIMAL EATS THE WHOLE FACTORY
Set the bowl down, and watch what happens to all of it.
The factory spent the length of a building keeping its work in order. The supplier's ingredient, the engineer's cooking, the structure the drying set, the smell the reactions built, the coating from the drum, each made in its own place, by its own hands, booked to its own account. And then the animal lowers its head and, in a single mouthful, undoes every division the factory was built on. It does not taste the protein, then the cooking, then the coat. It tastes a food. All of it at once, with no seam anywhere.
The animal does not taste a department. It tastes a food.
This is where the invisible palatant stands fully revealed, and it was never a thing at all. It is everything the factory had already done by the time the coating arrived: the aroma the cooking drew out of the raw mix, the structure that would hold the coat or shed it, the character written into the base before the drum was reached. The visible palatant, the one on the invoice, the one the drum applies, is real and does real work. But it lands into a performance already under way, and what the animal answers to is both at once, the added and the already-there, which it has no way of telling apart and no reason to try.
So the lesson this series has kept reaching lands, at last, at the scale of the plant. Palatability is not sealed in the coating, any more than in the recipe, the molecule, or the bowl; it is assembled, each time, in the animal, out of everything the food turns out to be. Which means the work of making a food an animal wants was never the last stage's alone. It began at the first, in the choice of what to cook and how.
And if that is so, one habit is worth retiring. Why do we still speak as though flavour begins at the drum, as though the food before it were a blank waiting to be made worth eating? The handful we took off the dryer, warm and already smelling of something, said otherwise on the first page. The food was telling its sensory story from the beginning. The coating only wrote the last line of it.
We divide the factory into operations. The animal encounters their consequences together.
References
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About the Author
Dr. rer. nat. habil. Dr. Seronei Chelulei Cheison is the founder and Chief Executive Officer of Sinonin Biotech GmbH, where he works with petfood companies on palatant sourcing strategies, the innovation of palatability enhancers, and the design of palatability assessment. A trained food enzymologist, he led alternative protein and palatant development at Mars Petcare before founding Sinonin, and his research on protein chemistry spans two decades, a doctorate from Jiangnan University, and a habilitation from the Technical University of Munich.
Sinonin Biotech GmbH is a partner in the ZEST project (Grant Agreement No. 101157382) and the PROSCALE project (Grant Agreement No. 101288362), both funded by the Circular Bio-based Europe Joint Undertaking (CBE JU) under the European Union's Horizon Europe research and innovation programme. Views and opinions expressed are those of the author only and do not necessarily reflect those of the European Union or CBE JU. Neither the European Union nor the granting authority can be held responsible for them.
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