Many factors influence milk coagulation : cheese recipe, rennet and culture activity, milk microbiological composition and origin (race of animals, region), quality of the feed, season (water consumption of livestock), etc. Because of that, it is impossible to predict the exact flocculation time, hardening speed and firmness of milk curd during the coagulation kinetics. In cheese making, this variability significantly affects the curd firmness at the critical cutting step. Solids retention from milk to cheese, and consequently cheese yield, are dramatically influenced by the variability of cutting firmness.
To resolve this problem and overcome the limitations of currently available qualitative devices and techniques, Rheolution developed CoaguSensTM: the first and unique instrument that measures in real time the evolution of firmness of milk during enzymatic coagulation or fermentation of milk.
At-line and real-time coagulationmonitoring for cheese process optimization
CoaguSensTM is an instrument installed near coagulation vats (at-line). Using a robust industrial touch screen, it runs CoaguTouchTM, an easy to use software environment allowing to interact intuitively with CoaguSensTM.
CoaguSensTM comes in two versions:
|CoaguSensTM Connect||CoaguSensTM Standalone|
|Communication Protocol with PLC||YES(Modbus TCP/IP, FTP)||NO|
|Process Control Operating Mode||Automatic (curd cutting via PLC)||Manual (Flashing beacon alarm)|
|Elasticity Range||0 Pa to 10,000 Pa||0 Pa to 3,000 Pa|
|Elasticity Precision||± 0.1 Pa||± 0.5 Pa|
|Temperature Range||68°F (20°C) to 122°F(50°C) (precision of ±0.1°F)||77°F (25°C) to 104°F(40°C) (precision of ±0.1°F)|
|Selectable Temporal Resolution||from 1 second to 120 minutes||from 10 seconds to 30 minutes|
|Measurements Duration||from 10 seconds to 1200 hours||up to 24 hours|
|Cabinet Dimensions||31" × 26" × 13" (788 mm × 660 mm × 330 mm) (H × W × D) + brackets to hold the unit|
|Total Weight||155 lbs (70 kg)|
|Supports and Fixtures||fixing structure (technical drawings available upon request)|
|Power Requirements||110-240 VAC ± 10%, 50 – 60 HzMax consumption 500 W||110-240 VAC ± 10%, 50 – 60 HzMax consumption 450 W|
|Communication Ports||USB 2.0, Ethernet||USB 2.0|
|User Interface||Color touchscreen|
|Ingress Protection||IP65 (cabinet in stainless steel 304, finish #4 brushed)|
|Instrument Calibration||Fast (5s) auto-calibration|
|Data Processing Functionalities||Data managing, analysing, displaying, storing and transferring|
|Process Calibration Operating Mode||Building a database of cutting elasticities for each specific cheese during the diagnosis phase|
Ergonomy & Simplicity
The functions of CoaguSensTM may be monitored using the built-in CoaguTouchTM software. The ‘process calibration’ mode of CoaguTouchTM is used to create a database containing the evolution of curd firmness for a specific cheese recipe. The statistical analysis of the database allows to determine the optimal cutting firmness that delivers improved retention rate and yield.
In the ‘process control’ mode (available only with CoaguSensTM –Connect), CoaguSensTM communicates continuously with a PLC-based control system. The optimal cutting firmness determined during the ‘process calibration’ phase can be entered by the user, loaded from the plant internal database or pulled automatically from the network. In production, during the coagulation of milk, once the optimal firmness is reached by the curd, a signal is sent to the automation system to start cutting the curd.
A password-protected administrator account is granted to the production manager. Using this account he will have a full control on the process monitoring parameters of CoaguTouchTM and will be able to customize and save the following plant-specific key information:
List of cheese recipes produced in the plant. Cheese recipes cutting parameters: target firmness, minimum and maximum time for cutting. Cheese/recipe specific maximum coagulation time. List of vats. List of cheesemakers & production operators.
Visualize the curd firmness
Visualize the data in a table form
Section & Parametrization of the test
Interface during the renneting
Interface after the curd cutting
Visualize the thermal history
Manage the cheese database
Manage the user database
Manage the coaguSens communication
CoaguSensTM is a process control instrument that measures in real time, without contact and non-destructively the shear viscoelastic modulus (firmness) of milk gels as a function of time during coagulation. Contrary to optical and thermal technologies, CoaguSensTM measures the absolute curd firmness of the milk gel during coagulation.
The patented technology behind CoaguSensTM is purely mechanical. A small amount of renneted milk is sampled from the coagulation vat and poured into a disposable sample-holder that has a flexible membrane at the bottom. A very gentle vibration (only a few micrometers) is applied to the sample and its response is measured without contact by a laser probe. The sample response is processed using a special mathematical model to calculate gel firmness. This process is repeated over the course of the coagulation kinetics at the frequency pre-set by the cheesemaker user.
Physically, once the sample is poured into the detachable sample-holder, the material and the flexible membrane form a composite and soft body able to react to external vibrations. This is made possible by the nature of the membrane that is flexible.
When a test is started, a low frequency-amplitude vibration is transmitted to the sample-holder connected to the vibrating unit. The composite body formed by the sample-membrane system freely vibrates in response to this dynamic excitation. The only unknown variable in the system, the viscoelasticity (firmness), can be deduced since all other parameters are known. The composite body’s vibrational response to the stimulus is influenced by the material viscoelasticity, a physics which is exploited by CoaguSensTM to measure the sample mechanical properties during a phase changing kinetics or at a steady physical state.