The Conversation We Need to Have
Five questions about what animals actually recognise as food — and why we keep measuring the wrong thing.
Somewhere tonight a cat will walk away from a bowl of food that is nutritionally faultless. Every amino acid balanced against a published requirement, every micronutrient supplemented, digestibility measured and documented, the whole formulation defensible to any regulator who cares to ask. And the animal will sniff it, decline it, and sit down beside it.
That refusal is the most important data point in our industry, and it is the one we have organised ourselves least well to understand.
The petfood industry is entering one of the most consequential periods of innovation in its history. Insect meals, microbial biomass, precision-fermented ingredients, cultivated meat and novel plant proteins are no longer confined to research laboratories or niche launches; they are steadily becoming part of mainstream product development, and the regulatory frameworks are beginning to move with them. The conversation has understandably centred on sustainability, nutritional adequacy, ingredient security and environmental impact. These are important discussions, and they will continue to shape the future of companion animal nutrition.
Yet they all rest upon a deceptively simple assumption.
That the pet willingly eats the food.
More importantly, that it continues to do so, day after day, bowl after bowl, long after the novelty has worn off.
Perhaps this is where our industry should pause.
For decades, palatability has been recognised as an essential component of product development, but seldom as its defining strategic challenge. It has often been viewed as the final optimisation step — something applied after the formulation has been completed and before feeding trials begin.
That perspective may no longer be sufficient.
As we progressively reformulate with lower-meat diets and alternative proteins, palatability is moving from the end of the development process to its very centre. It is becoming the bridge between scientific innovation and commercial success. In human food, the barrier to novel protein is persuasion; you can argue a person into a lentil. In petfood, the barrier is engineering. The animal will eat the bowl or it will walk away, and no marketing budget has ever changed its mind.
Owners buy the first bag. Pets decide the second.
I want to set out five conversations I believe we should be having. I have views on all of them, and I have deliberately not concluded any of them, because the people best placed to answer are scattered across formulators, ingredient developers, panel operators and researchers who rarely find themselves in the same room.
Have we confused nutritional replacement with behavioural replacement?
The industry has made remarkable progress in demonstrating that many alternative proteins can contribute to nutritionally complete diets. Essential amino acids can be balanced. Micronutrients can be supplemented. Digestibility continues to improve. In many respects, the question of nutritional adequacy is becoming increasingly manageable.
But nutrition and feeding behaviour are not the same challenge.
Replacing the nutritional contribution of meat does not necessarily replace the biological signals that companion animals have evolved to associate with food.
For much of our industry's history, meat has quietly performed several functions simultaneously. It has provided protein, energy and micronutrients, but it has also supplied free amino acids, nucleotides, animal fats, Maillard reaction precursors, volatile sulphur compounds and a great many other molecules that together create a sensory experience. We have rarely needed to separate these functions, because meat conveniently delivered them together.
Alternative proteins force us to do exactly that.
Meat does five jobs at once. We never asked which one mattered.
And here I find myself genuinely uncertain. If meat performs five jobs at once, which of them is load-bearing? I am not aware of published work that takes it apart — that holds the amino acid profile constant while removing the nucleotide contribution, or the reverse, and reports what the animal does. Within ZEST, Sinonin Biotech leads the assessment of mycoprotein biochemical and techno-functional properties and the development and testing of petfood prototypes, which is precisely the territory in which this question becomes practical rather than academic. I would be glad to be pointed towards work that has already answered it.
Perhaps the more interesting question is no longer whether alternative proteins can replace meat nutritionally.
Perhaps it is whether they can replace what meat communicates biologically.
Is meat an ingredient, or a sensory language?
One of the unintended consequences of alternative proteins is that they oblige us to reconsider what meat actually contributes.
Perhaps meat is not simply an ingredient. Perhaps it is a remarkably efficient carrier of sensory information — free amino acids that shape taste perception; 5'-nucleotides generated by the post-mortem breakdown of muscle tissue and almost entirely absent from plant material; animal fats that yield characteristic aroma compounds under process heat; Maillard and Strecker products that depend on sulphur amino acids many plant proteins supply only sparingly; and, behind all of it, the post-ingestive reinforcement that quietly teaches an animal what to choose next week.
These are not merely chemical constituents. Together they form a biological language through which dogs and cats recognise food.
When we remove meat, we are not only changing the source of protein. We are changing that language.
We are not changing the protein. We are changing the language.
Equally, alternative ingredients arrive speaking their own. Plant proteins may contribute bitter peptides, green or grassy notes and anti-nutritional compounds. Insect-derived materials bring different textural and aromatic characteristics. Fermentation products introduce another profile again.
These are not flaws. They are simply a reminder that every ingredient communicates something, whether or not we designed it to.
The question is whether we understand those conversations well enough to conduct them deliberately.
Are we designing for one animal, or two?
We speak of petfood palatability as though it were a single discipline. It may be closer to two.
Dogs, shaped by millennia of proximity to human settlements, display considerable dietary flexibility, and their food selection appears substantially odour-led. Cats remain obligate carnivores whose selection is more taste-dominant, whose format preferences are largely established around weaning, and whose sensory apparatus is tuned with unusual precision to animal-derived material.
One difference deserves to be stated plainly, because it is structural rather than a matter of degree. The gene encoding the sweet taste receptor subunit is non-functional in the cat.
Not diminished. Absent.
The cat's sweet receptor is not weak. It is absent.
Which means that a considerable portion of the toolkit available for managing bitterness in lower-meat canine diets is simply unavailable in the species that is also more bitter-sensitive, more texture-rigid and more neophobic than the dog.
I have a particular interest in this problem, having spent a large part of my research career on enzymatic protein hydrolysis and on the bitterness that hydrolysis generates. When you cleave a protein you expose hydrophobic residues, and hydrophobic peptides read bitter; I published on the simultaneous desalting and debittering of whey protein hydrolysates in 2007, and returned to the influence of environmental conditions and substrate pre-treatment on whey protein hydrolysis in a review with Ulrich Kulozik a decade later. The chemistry is not mysterious. What I am far less certain about is what the industry is actually doing with it now, in cats, at commercial inclusion levels, without recourse to sweetness.
I suspect practice here is well ahead of publication. If it is, I would rather hear it from the people doing the work than speculate about it from the outside.
There is a further observation that has been treated, I think, as a procurement inconvenience when it may be scientifically interesting. Trial data compiled by FEDIAF suggests that dogs may favour black soldier fly larvae meal while cats favour yellow mealworm — a plain divergence with no settled explanation. Lipid profile? Chitin fraction? Something in the volatile signature that one species reads as food and the other does not?
If we cannot explain why two domestic species rank the same two insects differently, it is worth asking how confidently we can predict acceptance of anything genuinely novel.
Are we designing formulations, or engineering preference?
Historically, palatability has been treated as a finishing operation. Formulate, extrude, dry, coat, validate. That workflow has served the industry exceptionally well.
But as meat inclusion declines, it may become increasingly difficult to separate formulation from palatability.
One observation illustrates this particularly well. In many dry petfoods, the overwhelming majority of the formulation passes through the extruder before a final coating stage delivers much of the product's sensory identity — and frequently those coatings still rely on animal-derived fats, digests or hydrolysates.
This is not a criticism. These ingredients remain highly effective, and their continued use is entirely rational.
It does, however, illustrate the nature of the transition we are undertaking. In a good many formulations we have replaced meat as a nutritional ingredient while continuing to depend upon it as a sensory technology.
We replaced meat as a nutrient. We kept it as a flavour.
It also explains something we say too rarely. The coating step is what makes dry formats forgiving; it separates the base matrix from the sensory signal and gives us a stage at which to correct course. Wet formats offer no such separation. They must be intrinsically palatable, first time, with nothing applied afterwards to rescue them.
Which raises an uncomfortable practical question. If lower-meat dry dog food is approaching a solved problem, what is the honest status of lower-meat wet cat food? Is anyone close? Or have we collectively, and rather quietly, deprioritised the hardest quadrant because the easier three pay sooner?
And behind that, a broader one. Are we replacing proteins, or are we beginning to redesign the mechanisms through which companion animals recognise food?
If it is the latter, palatability can no longer be regarded as something added at the end of development. It becomes a design discipline from the outset.
Are we measuring the right outcome?
The industry has long relied upon robust palatability methodologies, particularly paired preference testing, and these methods have served ingredient developers extremely well.
Yet the transition towards alternative proteins raises a question about what, exactly, we are measuring.
A two-bowl comparison is exceptionally sensitive to small formulation differences. That sensitivity derives from simultaneous presentation against a control — which is precisely what makes it invaluable during development, and precisely what makes it unlike any situation the animal will ever encounter at home.
Consider what that means for a genuinely novel diet. It is assessed on an unfamiliar aroma profile, at first exposure, in an animal whose neophobia is a feature of its biology rather than a defect in the product. Meanwhile the one mechanism that most favours reformulated diets, post-ingestive learning, requires repeated exposure to operate at all, and the design excludes it.
Commercial reality unfolds rather differently. Pets eat one food at home. Owners observe feeding behaviour across weeks and months. Confidence accumulates slowly. Repurchase follows repeated positive experience.
The trial rewards preference. The market rewards repurchase.
So let me ask the narrow version rather than the rhetorical one. Where is the ninety-day monadic comparison between an alternative-protein diet and its meat-based equivalent? I cannot find one published. If it exists, it deserves considerably more attention than it has received. If it does not, that absence tells us something about what we have chosen to measure, and what we have chosen not to look at.
Success depends less upon winning the first comparison than upon earning the next purchase.
The bowl is the only honest judge
The conversation around alternative proteins is usually presented as an ingredient story. It is equally a sensory story.
The companies that succeed over the coming decade may not be those with access to the newest protein technologies; many of those will become broadly available across the industry. The greater advantage may lie in understanding feeding behaviour more deeply than competitors — in integrating sensory chemistry, behavioural biology, process engineering, flavour science and nutrition into what might reasonably be called palatability engineering.
The term matters less than the shift in thinking it represents.
The industry has learnt how to formulate with meat. Its next task is learning how to formulate without relying upon it, while preserving the sensory experience that keeps pets returning to the bowl and owners returning to the shelf. That cannot be solved by nutrition alone, nor by flavour chemistry alone, nor by processing alone.
I have left these five conversations open on purpose. I am more interested in what the people running the trials and formulating the diets know than in restating what I think I know. If you are working on any of them — the deconstruction question, the feline bitterness problem, or the longitudinal data — I would rather have your answer than repeat my own.
We have spent a decade asking whether these proteins can nourish a dog or a cat.
The animal has been answering a different question all along.
A diet the animal refuses has an efficacy of zero.
Dr. rer. nat. habil. Dr. Seronei Chelulei CheisonLangwedel, Niedersachsen
Dr. rer. nat. habil. Dr. Seronei Chelulei Cheison is the founder and Chief Executive Officer of Sinonin Biotech GmbH, a biotechnology company focused on alternative protein and palatability enhancer innovation and application for petfood formulations. He formerly led alternative protein and palatant development projects at Mars Petcare, and spent close to two decades in academic research on enzymatic protein hydrolysis, holding a doctorate from Jiangnan University and a habilitation from the Technical University of Munich.
Sinonin Biotech GmbH is a partner in two consortia funded under the Circular Bio-based Europe Joint Undertaking: ZEST, on fungal fermentation of agricultural residues, and PROSCALE, on scalable microbial protein ingredients, which runs from September 2026 to August 2030.
Co-funded by the European Union under Grant Agreement No. 101157382 (ZEST) and Grant Agreement No. 101288362 (PROSCALE). Views and opinions expressed are however those of the author only and do not necessarily reflect those of the European Union or CBE JU. Neither the European Union nor the CBE JU can be held responsible for them.
