Application Note | CoaguSens™ Flex
Testing processed cheese meltability and functionality
Processed cheese plays an important role in the food industry, valued for its consistent quality, extended shelf life, and functional versatility in applications such as sandwiches, sauces, ready meals, and bakery products. One of the most critical attributes determining its performance in food applications is meltability. This property directly influences texture, mouthfeel, and visual appeal when the cheese is heated, making it a key factor in both product development and quality control.
Processed cheese functionality
The unique functionality of processed cheese is the result of a carefully balanced formulation and controlled manufacturing process. By blending natural cheese with emulsifying salts, water, and other ingredients under heat, manufacturers can standardize texture, flavor, and performance across batches. This control allows for targeted adjustments to meet specific market needs—such as enhanced melting for pizza toppings or improved slice integrity for burgers. The ability to fine-tune meltability without sacrificing stability is one of the reasons processed cheese is widely used in foodservice and industrial applications.
Meltability: a key quality attribute in processed cheese
Meltability in processed cheese refers to its capacity to soften and flow when exposed to heat. This property is influenced by factors such as moisture content, pH, fat-to-protein ratio, and the type and amount of emulsifying salts used. Optimal meltability ensures even coverage on heated foods, prevents excessive oiling-off, and delivers the desired stretch or flow characteristics. Inconsistent melt behavior can result in product defects like blistering, uneven coverage, or undesirable texture, impacting both appearance and consumer acceptance.
Firmness and texture
Firmness in processed cheese is closely linked to its meltability, as both are determined by the cheese’s protein network and water distribution. While firmer cheeses may retain structure during heating, excessive firmness can limit spreadability and create a chewy texture. Conversely, softer textures may enhance melt but risk collapse under heat. Manufacturers achieve the desired firmness by adjusting protein content, emulsifying salt concentration, and processing parameters such as heating time and shear rate.
Consistency
Consistency describes the uniformity of processed cheese properties—both within a batch and across production runs. From a functional perspective, consistency ensures that meltability, firmness, and texture remain predictable during application. Factors affecting consistency include the uniform blending of ingredients, stable pH control, and the prevention of phase separation during manufacturing. Maintaining high consistency not only supports brand reliability but also reduces waste and processing issues for industrial users.
Viscosity
Viscosity plays an important role in determining the flow behavior of processed cheese during melting. It affects how cheese spreads on heated surfaces, its stretch properties, and its ability to bind with other food components. Lower viscosity promotes smooth flow and even coverage, while higher viscosity supports structure retention in layered or filled products. Adjustments to moisture content, emulsifying salts, and fat distribution are commonly used to achieve target viscosity levels.
Understanding and controlling meltability, firmness, consistency, and viscosity are essential for ensuring processed cheese meets the performance expectations of both consumers and industrial clients. These parameters form the foundation for evaluating functionality and guide formulation improvements to align with evolving market demands.
In the next section, we will explore practical approaches for assessing these properties in real-world scenarios, as part of our Case Study: Testing meltability in processed cheeses.
Case Study: Testing meltability in processed cheeses
Instrument: CoaguSens™ Flex - Precision testing of processed cheese firmness and meltability
CoaguSens™ Flex is a precision analytical instrument developed for the dairy sector to characterize the rheological and viscoelastic properties of milk gels and cheeses. It provides real-time monitoring of enzymatic and acid coagulation processes in milk and quantifies gel firmness and structural development under controlled thermal conditions. The system also enables meltability studies of cheeses (natural or processed) by measuring temperature-dependent viscoelastic responses, delivering reproducible data on functional performance.
By generating precise rheological parameters, CoaguSens™ Flex supports food scientists, technologists, and process engineers in optimizing formulations and ingredient dosage. Its analytical capabilities facilitate the adjustment of process parameters to consistently achieve defined functional targets, including texture, firmness, and melt behavior.
Combining versatility with high analytical accuracy, CoaguSens™ Flex is suited for both research and development—where it advances the understanding of structure–function relationships in dairy systems—and quality control, where it ensures product uniformity, reduces variability, and maintains compliance with industrial performance standards. The instrument measures the following parameters as a function of temperature:
- the shear elastic modulus (G′): measuring the firmness of the gel;
- the shear loss modulus (G’’): measuring the viscous behavior of the gel;
- the loss tangent [tan(δ)]: defined as the ratio G’’/G’ indicating the proportion of viscous behavior compared to the elastic behavior of the sample.
Results
Melting kinetics
Figure 1: Comparison of the melting profiles (time evolution of the elastic modulus or firmness) of Velveeta, Laughing Cow, Cheese Whiz and Kraft Single processed cheeses between 4 °C and 70 °C.
Studying firmness and melting speed of processed cheeses with CoaguSens™ Flex provides precise rheological insights, enabling manufacturers to optimize formulations, emulsifier balance, and thermal behavior for consistent texture, controlled meltability, and improved performance in industrial, culinary, and consumer applications. The meltability curves obtained using the CoaguSens™ Flex give multiple indications:
Kraft Slice begins as the firmest sample (~100,000 Pa), reflecting a dense protein–emulsifier matrix, but also melts the fastest, with G′ collapsing below 20,000 Pa in under 2 minutes. It shows high rigidity and moderate structural persistence under heat.
Velveeta starts moderately firm (~50,000 Pa) and melts rapidly, stabilizing at low elasticity. It balances initial strength with fast fluidization, ideal for smooth, uniform melt applications.
Laughing Cow has lower initial firmness (~35,000 Pa) yet retains its structure slightly longer, with a slower, more gradual G′ decay. It ends with higher residual elasticity, indicating a softer but more stable melted texture.
Cheez Whiz is the least firm from the outset (<5,000 Pa) and exhibits negligible structural decay, behaving essentially as a fluid throughout. Its formulation prioritizes pourability rather than gel strength.
Figure 2: Comparison of the elastic modulus (firmness) of Velveeta, Laughing Cow, Cheese Whiz and Kraft Single processed cheeses at 4 °C and 70 °C.
![Loss tangent [tan(δ)] and viscous behavior of Velveeta, Laughing Cow, Cheese Whiz and Kraft Single processed cheeses at 4 °C](data:image/svg+xml;base64,PHN2ZyB2aWV3Qm94PSIwIDAgNzY4IDg5NCIgd2lkdGg9Ijc2OCIgaGVpZ2h0PSI4OTQiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PC9zdmc+)
Figure 3: Loss tangent [tan(δ)] and viscous behavior of Velveeta, Laughing Cow, Cheese Whiz and Kraft Single processed cheeses at 4 °C
Figure 4: Loss tangent [tan(δ)] and viscous behavior of Velveeta, Laughing Cow, Cheese Whiz and Kraft Single processed cheeses at 70 °C
Velveeta
Velveeta is a pasteurized processed cheese product made from milk, whey, emulsifying salts, and oils, homogenized and heat-treated to ensure stability and smooth texture, widely used in sauces, dips, and processed foods due to its uniform melting properties.
At 4 °C, Velveeta exhibits moderate firmness (~45,000 Pa) with elastic-dominant behavior (tan(δ) ~0.3). Heating to 70 °C causes a drastic loss of structure (<2,000 Pa) and a sharp rise in tan(δ) (~0.7), marking a transition to viscous-dominant behavior. This explains its smooth, uniform meltability.
Laughing Cow
Laughing Cow is a portioned processed cheese spread produced by blending natural cheeses with cream, milk powders, and emulsifying salts, then heat-sterilized for shelf stability, yielding a spreadable, smooth product commonly consumed as a snack or applied to bread and crackers.
Laughing Cow is moderately firm at 4 °C (~35,000 Pa) and retains considerable elasticity when heated (~7,000 Pa at 70 °C). Its tan(δ) remains stable at ~0.3, indicating a stable viscous contribution while maintaining structural balance. This results in a soft, spreadable texture rather than full fluidity.
Cheese Whiz
Cheez Whiz is a processed cheese sauce composed of cheese, whey, oils, and emulsifying salts, thermally processed to create a shelf-stable, pourable product with extended consistency, primarily used as a dip, topping, or flavoring agent in fast foods and convenience applications.
Cheez Whiz is weakly structured even at 4 °C (~5,000 Pa), with a relatively high tan(δ) (~0.5) that reflects viscous-dominant properties. At 70 °C, its G′ falls below 1,000 Pa while tan(δ) remains high, confirming its nature as a pourable emulsion with minimal gel network integrity.
Kraft Singles
Kraft Singles are individually wrapped processed cheese slices consisting of natural cheese, whey, vegetable oils, emulsifying salts, and stabilizers, pasteurized to ensure microbiological safety and consistent meltability, specifically designed for use in sandwiches, burgers, and other ready-to-eat applications.
Kraft Slice is the firmest at refrigeration (~100,000 Pa) with a moderate elastic behavior (tan(δ) ~0.45). When heated to 70 °C, G′ drops steeply to ~4,000 Pa and tan(δ) rises toward 0.55, indicating structural changes during melting.
Using precise measurement to improve processed cheese functionality
Conclusion
This study examined the meltability and functional properties of Velveeta, Laughing Cow, Cheez Whiz, and Kraft Singles using the CoaguSens™ Flex. Processed cheese performance depends on formulation factors such as protein–fat ratio, emulsifying salts, pH, and moisture. Key parameters measured included the shear elastic modulus (G′), viscous modulus (G″), and loss tangent [tan(δ)], allowing precise evaluation of firmness and melt behavior across temperatures.
At 4 °C, Kraft Slice was the firmest (~100,000 Pa), followed by Velveeta (~45,000 Pa) and Laughing Cow (~35,000 Pa), while Cheez Whiz was weakly structured (<5,000 Pa). Heating to 70 °C reduced firmness in all samples, though with different kinetics: Kraft Slice melted rapidly (~4,000 Pa), Velveeta fluidized completely (<2,000 Pa), Laughing Cow retained partial structure (~7,000 Pa), and Cheez Whiz remained soft throughout.
Viscous behavior, captured by tan(δ), confirmed these trends. Velveeta shifted from elastic-dominant (~0.3) to viscous (~0.7), Laughing Cow remain stable (~0.3), Kraft Slice rose slightly (0.45–0.55), and Cheez Whiz remained viscous (~0.5) regardless of temperature.
CoaguSens™ Flex provides a fast, reproducible, and quantitative way to measure cheese meltability. Its ability to capture firmness, melting speed, and viscous–elastic balance under heating makes it an invaluable tool for R&D formulation design and QC consistency monitoring, ensuring products meet functional performance requirements with minimal trial-and-error.
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