Technical and scientific analysis of maturing processes:

Technical and scientific analysis of maturing processes: Monitoring of the Aw index and the dew point using the integrated GUBELOG-01 system

The food production sector, particularly the curing of meat and dairy products, is currently undergoing a profound technological transformation driven by the need to combine centuries-old traditions with stringent microbiological safety protocols and industrial efficiency requirements. Curing is not a simple waiting process, but a complex sequence of biochemical and physical transformations where millimetric control of the environmental microclimate determines the success or failure of an entire production batch. In this scenario, variables such as Water Activity (Aw) and Dew Point (Dew Point) emerge as key parameters for preventing pathogenic bacterial growth and unwanted fungal growth, while ensuring the development of the desired organoleptic properties.

Gubellini Electronics developed the GUBELOG-01 system to specifically address the critical issues of these market niches, providing an industrial-grade datalogging architecture capable of operating in hostile environments and processing complex data using a proprietary mathematical engine and artificial intelligence. The adoption of a distributed network based on CAN-Click sensors allows for comprehensive monitoring of every corner of the curing rooms, overcoming the historical limitations of traditional instrumentation, which is subject to rapid degradation in atmospheres saturated with humidity, salts, and ammonia.

Thermodynamic Fundamentals of Aging: Water Activity and the Aw Index

The water present in a food is not uniformly distributed nor does it possess the same chemical and physical properties throughout. A distinction is commonly made between bound water, the fraction firmly retained by the macromolecules of the food (such as proteins and carbohydrates), and free water, which serves as a solvent for biochemical reactions and is the only water effectively available for the metabolism of microorganisms. The Water Activity (Aw) index quantifies this energy availability of water and represents the most reliable parameter for predicting the microbiological stability of a product.

The GUBELOG-01 system, through its internal mathematical engine, implements the physical formula for determining water activity based on vapor pressure:

$$Aw = \frac{p}{p_s}$$

In this equation, $p$ represents the partial pressure of water vapor on the surface of the food product, while $p_s$ indicates the saturation pressure of pure water vapor at the same temperature. In a stable curing room, a dynamic equilibrium is established between the product and the surrounding air, called Equilibrium Relative Humidity ($ERH$). When this equilibrium is reached, the water activity of the cured meat or cheese is numerically equal to the relative humidity of the air divided by one hundred:

$$Aw = \frac{ERH}{100}$$

Constantly monitoring this value using Gubellini Electronics' CAN-Click sensors helps prevent the growth of critical pathogens such as Salmonella spp. or Listeria monocytogenes, which require specific Aw levels to replicate. In long-aged sausages, the reduction in water activity, induced by the controlled loss of moisture and the increase in sodium chloride concentration, becomes the predominant shelf-life factor compared to pH.

Weight loss dynamics and microbiological safety

During the maturation of salami and soppressa, a significant reduction in internal humidity occurs, ranging from an average initial value of 50-70% to a final value of between 27% and 45%. This drop in humidity causes the Aw index to decrease from values close to 0.99 (fresh meat) to a safe level of 0.85-0.89. Scientific research has shown that a 25% weight loss represents a fundamental safety threshold for inhibiting the multiplication of potential pathogens.

The GUBELOG-01 facilitates this monitoring by integrating data from various types of sensors. Through the 4-20mA analog inputs, it is possible to interface precision industrial scales that transmit the weight in real time to the datalogger. Gubellini Electronics' mathematical engine instantly correlates the mass variation with the environmental parameters detected by the CAN-Click sensors, providing a predictive estimate of the time remaining to reach microbiological stability.

Product

Initial Aw

Aw Finale (Target)

Safety Condition

Fresh Meat

0.98 - 0.99

N/A

High risk

Seasoned Salami

~0.96

0.85 - 0.89

Pathogen inhibition

Hard Cheese

~0.98

0.88 - 0.92

Enzyme stability

Surface Condensation Management: The Dew Point

One of the most insidious challenges in managing a curing room is condensation. When the product's surface temperature drops below the dew point of the surrounding air, water vapor condenses into liquid form, creating a film of water that promotes the growth of toxic mold (green or black) and accelerates the decay process.

The dew point is a complex function of ambient temperature and relative humidity. Gubellini Electronics has integrated specific algorithms into the GUBELOG-01 firmware and DataStudio software for calculating this value in real time. For standard applications, the mathematical engine uses the Lawrence linear approximation:

$$Td \approx T - \left( \frac{100 - RH}{5} \right)$$

For contexts requiring high scientific precision, such as food research laboratories or PDO production, the system uses the revised Magnus-Tetens coefficients:

$$Td = \frac{\lambda \cdot \ln\left( \frac{RH}{100} \right) + \frac{\beta \cdot T}{\lambda + T}}{\beta - \left( \ln\left( \frac{RH}{100} \right) + \frac{\beta \cdot T}{\lambda + T} \right)}$$

With parameters set to $\beta = 17.625$ and $\lambda = 243.04$ °C, the system guarantees superior metrological accuracy, essential for operating in high humidity environments (close to saturation) typical of the ripening of soft cheeses. Using the DataStudio suite, the operator can graphically view the surface temperature line superimposed on the dew point line; the reduction of the thermal delta between these two curves immediately activates visual and audible alarm signals, allowing ventilation flows to be adjusted before damage occurs.

The problem of mold and ventilation

White mold is considered a natural and desirable part of the curing process for many cured meats, as it protects the product and enriches its flavor profile through proteolysis and lipolysis. However, insufficient ventilation or humidity above 80-85% can favor the growth of non-noble mold. Ventilation has the dual purpose of homogenizing the temperature in the chamber and removing excess moisture that exudes from the products.

The GUBELOG-01 system solves ventilation complexity through its two configurable digital outputs, capable of driving power relays for motors or solenoid valves. The activation logic is managed by the mathematical engine, which can cross-reference data from multiple CAN-Click sensors to activate fans only when necessary, such as when relative humidity exceeds a set threshold or when the ambient temperature approaches the dew point. This "intelligent" approach prevents excessive ventilation that could cause a "hard crust" effect, ensuring uniform drying and significant energy savings.

Environmental Complexity and Hardware Solutions from Gubellini Electronics

Curing rooms are chemically aggressive environments. Constantly high relative humidity (often above 85-90%) is combined with ammonia and mineral salt fumes from the fermentation and curing processes. Standard capacitive humidity sensors tend to become saturated or undergo irreversible drift due to chemical corrosion of the polymer dielectrics.

GUBELOG-01: Designed for Extreme Reliability

The GUBELOG-01 data logger is designed to withstand such conditions, featuring a PA12 Nylon casing with IPX7 waterproofing certification. Full insulation protects the internal electronics from acidic condensation, while the 26-pin automotive-grade JAE main connector ensures oxidation-free signal transmission thanks to integrated silicone seals and a Click-Lock mechanical locking system.

Main features of the GUBELOG-01 hardware architecture:

• Input Capacity: Simultaneous acquisition of 38 channels, allowing for detailed monitoring of large storage facilities.

• Analog Versatility: Programmable 0-5V or 4-20mA sensor inputs, with built-in precision pull-down resistors for “Plug & Play” configuration of industrial probes.

• Vibration Resistance: Architecture tested for heavy industrial environments, ideal for installations near refrigeration units or ventilation systems.

• Memory and Data Security: Saving to Micro-SD in RAW format and secure writing to prevent data loss in the event of a sudden power failure.

Innovation in CAN-Click sensors Environment 3

To overcome the fragility of traditional sensors, Gubellini Electronics proposes the use of CAN-Click sensors from the Environment 3 series. These sensing nodes are not simple temperature and humidity transducers, but integrate MEMS units with high linearity and chemical resilience.

The Environment 3 sensor by Gubellini Electronics stands out for:

1. Ammonia Resilience: Unlike standard capacitive technologies, the MEMS chip maintains accuracy even in the presence of aggressive organic vapors.

2. Integrated Gas Scanner: Detects Volatile Sulfur Compounds (VSCs) and Volatile Organic Compounds (VOCs), acting as a sentinel for early bacterial rot.

3. Edge Calculation: The microcontroller on board the CAN-Click sensor locally performs Dew Point and Vapor Pressure Deficit (VPD) calculations, sending pre-processed data packets to the central data logger.

4. Signal Integrity: Digital bus communication ensures immunity to electromagnetic interference present in industrial sites, allowing for wiring lengths that would otherwise be impossible for analog signals.

CAN-Click Environment 3 specifications

Value / Capacity

Advantage in Seasoning

Temperature Accuracy

±0.5°C

Accurate Dew Point Calculation

Relative Humidity Tolerance

±3% RH

Monitoring of the Aw safety index

VSC/VOC Gas Detection

Yes

Early diagnosis of bacterial contamination

Communication Interface

Digital (Bus)

High reliability in humid and large environments

Advanced processing and analysis via AI Analyst

The GUBELLINI DataStudio software completes the ecosystem, transforming binary logs into certified technical documents. The flagship module, AI Analyst, is an expert virtual assistant that automates the interpretation of telemetry data. AI Analyst not only generates graphs, but also works through a multi-agent system to provide diagnostic conclusions.

The AI Analyst workflow for seasoning includes:

• Dataset Audit: Verifies that temperature and humidity data are continuous and free of electrical artifacts, flagging any sensors that require calibration.

• Mathematical Processing: The math engine applies the physical laws of ideal gases line by line to calculate the estimated $Aw$ index and the total time spent above the dew point.

• Diagnostic Report Generation: The AI generates a natural language document summarizing batch compliance. For example: "Batch #402 maintained a water activity below 0.88 for 98% of the cycle duration. A 15-minute condensation spike occurred on day 12 due to the loading door being left open for an extended period."

This level of automation relieves production managers of the burden of time-consuming and error-prone manual analysis, while providing an unalterable “Audit Trail” for health inspections and internal quality controls.

Remote Monitoring and HACCP Compliance: The Role of GUBECloud

In the modern agri-food landscape, traceability and immediate data availability are fundamental regulatory requirements. The GUBECloud service extends the functionality of the GUBELOG-01, connecting the ripening facility to a secure cloud platform via Wi-Fi or NB-IoT cellular connection.

Real-time Telemetry and Dashboarding

Through GUBECloud, data acquired from the CAN-Click sensors is transmitted at programmable intervals (up to once per minute), enabling remote monitoring via smartphone or tablet. The dashboard is fully customizable: the user can rename inputs to reflect the actual cell structure (e.g., "Cell 1 Aw Probe", "Bottom Dew Point Pressure") and display needle indicators for critical parameters.

Advantages of GUBECloud remote monitoring:

• Push and Email Notifications: Instant alarms if the temperature exceeds critical thresholds (e.g. >18°C, which favors abnormal fermentation) or if the humidity drops below safety limits.

• Cloud-Side Automations: Create virtual logic alarms without modifying local hardware. For example: "Alert me if the dew point temperature is close to room temperature for more than 10 minutes."

• Automatic Reporting: Configure weekly or monthly reports in PDF/CSV format sent via email, perfect for demonstrating cold chain and microclimate maintenance to certification bodies.

HACCP integration and traceability

HACCP regulations require systematic recording of maturation and aging parameters. The Gubellini Electronics system fully automates this process. The datasets saved locally on the GUBELOG-01's microSD card and those archived on GUBECloud constitute an unalterable historical record. In the event of a complaint or health inspection, the company can display detailed timelines that prove the continuity of environmental parameters, ensuring the complete food safety of the products placed on the market.

Specific use cases: From meat aging to cheese maturing

The extreme flexibility of Gubellini Electronics' mathematical engine allows monitoring to be adapted to the technical characteristics of very different products.

Dry-aging of beef

Dry-aging is a delicate process aimed at tenderizing muscle mass through the action of endogenous enzymes. European regulations establish very precise parameters: surface temperature between -0.5°C and +3.0°C and a maximum relative humidity of 85%.

The GUBELOG-01, connected to airflow sensors via its digital frequency inputs, ensures that air movement remains constantly between 0.2 and 0.5 m/s, a value essential for preventing surface bacterial growth during the dry-aging process. The AI Analyst is able to calculate the MKT (Mean Kinetic Temperature), providing a much more accurate assessment of the heat stress accumulated by the meat than a simple arithmetic mean.

Maturing of washed and bloomy rind cheeses

For cheeses, aging conditions vary dramatically depending on the type. Soft cheeses require high humidity (up to 95%) to encourage the development of noble surface molds (blooming rind), while hard cheeses require drier conditions to prevent excessive drying, which would cause cracking.

Gubellini Electronics monitoring allows for scientific management of turning and brine rinsing. By analyzing the humidity gradient between the core of the wheel and the surface using needle sensors interfaced with analog inputs, the system indicates the exact moment to turn the cheese to ensure regular evaporation and the formation of a uniform crust.

Analysis of critical variables using virtual sensors

A distinctive advantage of Gubellini Electronics technology is the ability to generate "virtual sensors": mathematically derived, high-level information that does not require expensive additional hardware.

The mathematical engine implements the following virtual analyses for seasoning:

1. Vapor Pressure Deficit (VPD): Unlike relative humidity, VPD indicates the actual capacity of the air to extract water from the product. Too high a VPD causes surface fouling; too low a VPD promotes rotting.

2. Dynamic Aw Estimation: By combining ambient temperature, relative humidity and barometric pressure via CAN-Click sensors, the system provides a continuous estimate of water activity without the need for destructive sampling from the batch.

3. Cumulative Ripeness Index: Based on the Arrhenius equation, this virtual sensor integrates temperature over time to predict the achievement of optimal ripeness (proteolysis and lipolysis), helping plan product exit from the cell with millimeter precision.

Conclusions: Operational Excellence in Food Datalogging

Monitoring the Aw index and dew point is no longer just a matter of regulatory compliance, but has become the cornerstone of the quality and reputation of meat and cheese producers. With the GUBELOG-01 system, Gubellini Electronics has transformed data logging from passive data recording to an active and predictive analysis tool.

The CAN-Click sensor-based architecture solves the historical problems of corrosion and sensor instability in saturated environments, while the mathematical engine and AI Analyst provide clear answers to complex problems, automating condensation prevention and ensuring microbiological stability. Integration with GUBECloud ensures modern plant management, offering transparency, timely alarms, and impeccable reporting for HACCP compliance. Adopting Gubellini Electronics solutions means investing in technology that protects product value, reduces waste, and certifies the excellence of the production process at every stage.