How to measure and analyse the texture of food, cosmetics, pharmaceuticals and adhesives.

Tuesday, 17 July 2018

Viscoelasticity in the Food Industry

Stretchy cheese finger
The vast majority of food materials show a combination of viscous and elastic behaviour although many show much more of one than the other.

There are some exceptions – hard crackers are generally completely elastic, whereas oil and runny honey usually show no elastic behaviour. Viscoelastic testing is best used as a comparative measure as many food products have an unusual geometry, so conventional viscoelastic equations cannot be used to find fundamental parameters.

If a cracker is not completely elastic when bitten, it may have become stale. The degree of viscous behaviour can be measured to study this effect. A sample so brittle is not easily clamped without fracturing, so tensile testing is not an option, but equally it is not a suitable shape for compression.