Rheology vs. texture: Understanding the differences and their importance

When it comes to understanding the physical properties of materials, particularly in food science and cosmetics, two critical concepts often come into play: rheology and texture. While these terms are sometimes used interchangeably, they shape everyday experiences from how smoothly your lotion spreads to how satisfyingly crunchy your chips are and refer to distinct aspects of material properties. Let’s delve into the differences between rheology and texture, their significance, and how they are applied in various industries.

Understand chewiness/bite force graphs

Whether it's the satisfying resistance of a chewy granola bar or the clean snap of a crisp vegetable, bite force influences mouthfeel, satisfaction, and overall enjoyment. These mechanical properties help define product identity — a chewy sweet should stretch and resist breaking easily, while a firm meat alternative must provide a consistent bite. Measuring chewiness and bite force provides manufacturers with essential data for ensuring product quality, replicating desired textures, and aligning with consumer expectations across a range of applications.

Using a range of blade options which attach to the arm of the instrument, this is a property where the Texture Analyser excels in measurement. Exponent software controls the distance that the blade comes down onto/into the sample to achieve the ‘biting’ action, as if the teeth were in alignment, hence mimicking the action of a consumer.

Learn how to fully understand an adhesion graph

Stickiness/adhesion is a common textural and physical property that is possessed by a wide range of products including food, cosmetics, pharmaceutical products and, of course, adhesives and adhesive tapes. Testing this property is key to understanding, manipulating and controlling the performance or enjoyment of a product whether it is eaten, spread on the skin or used as an important everyday tool or medical requirement. Stickiness/adhesiveness/bioadhesion can be a highly desirable requirement of a product or can be a negative undesirable property.

This is a property where the Texture Analyser excels in measurement. Exponent software has a unique test (the Adhesive Test) which allows the control of force that a probe comes down onto the sample to achieve a controlled bonding between the two surfaces for a chosen period of time. After this bonding preparation stage the probe withdraws and the adhesion properties to separate the two surfaces is measured.

Controlling your sample testing environment

Samples such as gels, confectionery, waxes and high fat or oil content products are very temperature critical and as such careful equilibrating and stabilising of testing temperature need to be considered to provide reproducible comparative texture analysis results.

Stable Micro Systems solve these temperature associated problems by offering a range of temperature control solutions to suit various temperature range and testing dimension requirements.

Weigh as you test using your Texture Analyser

For product developers and manufacturers, precision in testing is critical. The Dynamic Integrated Balance, compatible with Stable Micro Systems' Connect and Plus range of Texture Analysers, provides simultaneous force and weight measurement. This innovation opens new possibilities in understanding how products perform during real-world usage.

The power of simultaneous measurements

Imagine being able to measure not only the force required to actuate a soap/condiment dispenser but also the exact amount of product delivered with every press. The Dynamic Integrated Balance enables just that by combining dynamic weighing with physical testing. With data collected at 500 points per second, you gain insights into:

Turn your Texture Analyser into a Penetrometer

Penetration is the method used to measure consistency which is the resistance a sample exhibits to deformation by an applied force.

A Penetrometer is a device that provides a rapid empirical method for measuring the denseness, compaction, consistency or penetrability of a wide variety of solid, semisolid, food and non-food products. These typically include soil, agricultural produce, or semisolid petroleum products in the pharmaceutical (such as creams and ointments), civil engineering, agriculture, geology and scientific exploration industries.

Testing in the lab: Dough Inflation

The Dough Inflation System enables the rheological properties of dough to be measured during biaxial stretching, which is the deformation in the cell wall material surrounding an expanding gas bubble during proof and baking. It provides a precise, digital measurement of dough expansion under conditions of strain and strain rate similar to those encountered in baking producing graphical and spreadsheet data for optimising recipes, proofing, shaping and baking conditions.

Understand your Texture Profile Analysis tests and analysis

Texture Profile Analysis (TPA) is a widely used method in food science to evaluate textural properties. The test involves a double compression cycle of a bite-size piece of food using a compression probe that simulates the biting action. Data is then extracted from the resulting force-time curve to provide a number of textural parameters that correlate well with sensory evaluation of those parameters.