How to Measure Crispness and Crunchiness

CRISPNESS/CRUNCHINESS is a property manifested by a tendency when subjected to an applied force to yield suddenly with a characteristic sound. It is commonly the textural property possessed by snacks (potato chips), breakfast cereals, fresh fruit and vegetables and some baked products (biscuits, crackers). This property can be measured during break strength testing.

These types of products are usually associated with sharp triangular curves displaying an obvious break point (when tested individually) or produce a 'jagged' multi-peak curve when tested 'in bulk'. The number of peaks produced are as a result of the fracture events that have occurred during the test. Counting the number of force peaks, the average dropoff and measuring linear distance are common calculations applied to such curves. Crispness is usually associated with many small fracture peaks. Whilst a crunchier product may possess the same number of curves the drop from peak to trough will be significantly higher and the linear distance increased accordingly.

The Acoustic Envelope Detector can by employed for any material which produces an audible noise when tested as it captures another dimension (i.e. sound) during the test which can also be analysed and used as a measured product feature. This is usually for acoustic analysis testing of brittle materials and the acoustic signal is as a result of a crack, break, snap or failure of some type.

Typical properties that can be obtained from a texture analyser graph:

Rupture Point, Crispness, Fracturability, Crunchiness, Brittleness, Fracture Strength, Fracture Distance, Work of Failure, Breaking Strength

Typical Texture Analyser graph with annotated properties of breakfast cereal bulk compression

Typical Probe/Fixture used for Measurement:

Single pieces of homogenous product:

Three Point Bend Rig >>

Knife Blades >>

Small Cylinder Probes >>

Multi-particulate or non-uniform products:

Ottawa Cell >>

Kramer Shear Cell >>

The above are only typical examples of crispness/crunchiness measurement. We can, of course, design and manufacture probes or fixtures that are bespoke to your sample and its specific measurement.

Once your measurement is performed, our expertise in its graphical interpretation is unparalleled – no-one understands texture analysis like we do. Not only can we develop the most suitable and accurate method for the testing of your sample, but we can prepare analysis procedures that obtain the desired parameters from your curve and drop them into a spreadsheet or report designed around your requirements.

Show me more properties that a Texture Analyser can measure...

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