The situation
A manufacturer wanted to replace part of the meat in a burger with plant protein, for cost and for a nutrition claim. Previous trials had held together on the line and crumbled on the plate.
Why it is hard
Plant protein gels less effectively than meat protein and binds water differently. Up to moderate substitution the familiar texture can be held or even improved. Push further and the failures arrive together: phase separation, a rubbery or grainy bite, flavour notes that were not there before, colour drift, and a product that cooks and then crumbles because nothing is holding the particles to each other.
Texturised protein makes this worse before it makes it better.
It brings the fibrous bite the product needs, and it is a structural particle rather than a binder, so adding it increases the amount of material that something else has to hold together.
What was done
The bind was treated as a separate problem from the texture, which it is. The texturised particle was specified for bite and hydration, and a separate binding system was built around it rather than expecting the particle to do both. Hydration of the texturate was tightened, because over and under hydration both appear in the eating quality and the tolerance is narrower than most trials assume. Colour and flavour were addressed deliberately, since the particle is pale and carries almost nothing of its own.
What it shows
That a hybrid product fails at the bind rather than at the protein.
