Patent ID: 8404290

Claim:
A method for shaping at least one food product by cryoextrusion, comprising the steps of: extruding a first food product through an extruder comprising at least one extrusion screw driven by a motor and a nozzle at the output of said at least one extrusion screw, the extruder being provided with a double jacket surrounding the extrusion screw and in which circulates a coolant, the double jacket consisting of one or more independent modules, each module being provided with a coolant inlet orifice receiving liquid coolant and a coolant outlet orifice allowing gaseous coolant to exit the module; acquiring a temperature of the first food product at the screw outlet with a data acquisition and processing system; acquiring a temperature of coolant gas at the coolant outlet orifice with the data acquisition and processing system; injecting liquid coolant into one or more of said modules, a difference Δ being defined as the difference between an actual temperature of the first product at the output and a temperature setpoint desired for the product at the output, wherein a first curve of a setpoint for the temperature of the coolant gas at the coolant outlet orifice versus Δ is programmed in said data acquisition and processing system, the first curve being organized in first and second regions connected with and surrounding a third region, the first and second regions being almost flat, the third region being almost vertical and extending through values of Δ close to 0; calculating the value of Δ; depending on the sign of the difference Δ and its absolute value, said data acquisition and processing system determines on said first curve the coolant gas temperature setpoint; and controlling the temperature of the gaseous coolant at the coolant outlet orifice based upon the coolant gas temperature setpoint through said injection of liquid coolant into said one or more modules.