Viability theory to control complex food: an application to the Camembert cheese

Scientific context

The issue of studying a food process is to fi nd the set of controls allowing to reach a quality target with the respect to the manufacturing constraints. Moreover, the aim of this work, having the set of controls, is to select a robust processcontrol. It is crucial for food industries to avoid risky controls. Viability theory (Aubin, 1991b) is a relatively new method for studying complex dynamical systems, focusing on the preservation of some properties of the system (constraints in the state space). The viability framework was adapted to a camembert ripening model to build a capture basin to reach a prede ned quality target. Finally, within the set of the viable trajectories, a robust one improving the camembert cheese ripening process was sought.

Computational context

A viability tube requires more than 50 million execution of the model. In the Octave version of this model, 2 computation months were required on a single PC.

Issues

The model was initially developed under Matlab, which is a proprietary software with restrictive licences, forcing to buy a licence per computation node. Porting the code into Octave was thus necessary!

Plateform improvements

• File navigation between task in the Workflow

Scientific results

The cheese ripening process was shortened by four days without signi cant changes in the microorganism kinetics. The quality target was reached and the sensory properties of the cheeses produced were similar to those produced understandard conditions.