Texture Analysis Glossary

GLOSSARY OF TEXTURE ANALYSIS TERMS

Coefficient of Friction

the ratio of the force required to move one surface over another to the total normal force applied to those surfaces.

Compression Testing
the sample is "compressed" with a probe of greater surface area to that of the sample.

Creep Testing
sample is compressed to a target load and held for a period of time. The instrument moves to maintain the target load and the distance moved is used as an indicator of sample elasticity.

Deformation
the change in height of a sample when a force is applied.

Fatigue Testing
test is cycled so that the recovery properties of the sample can be evaluated

Extrusion Testing
the sample is compressed until flow commences through an outlet. Texture analysis utilizes both forward (forced through an aperture) and backward extrusion (forced back around the compressing probe).

Load Cell
electro-mechanical device which records the mechanical response of the sample.

Multiple Point Analysis
analysis of the sample properties using multiple points of penetration to provide a cross-sectional overview.

Penetration Testing
the sample is "penetrated" with a probe of smaller surface area than that of the sample. This creates both shear and compression forces within the sample and provides a good indication of product hardness and consistency.

Shear Testing
blades or wires are utilized to cut through the sample and evaluate cross-sectioned characteristics using a combination of compression, shear and tearing forces dependant upon the geometry of the cutting fixture.

Snap Testing
used to assess the fracture and bend characteristics of solid materials supported at either end and compressed in its center.

Stress Relaxation
sample is compressed to a target distance and held for a period of time. The sample relaxes under constant stress and the rate and degree of relaxation is used to evaluate sample elasticity, freshness, etc.

Target Unit
either Load, Distance or % Deformation that the texture analyzer travels to post trigger.

Tension Testing
the sample is fixed to both the base and the traveling beam of the texture analyzer and "stretched" via an upward movement.

Texture Profile Analysis
procedure developed within the food industry using uniaxial compression cycles to assess the mechanical properties of a sample. Two consecutive cycles from a single point of trigger are applied under a constant speed from which seven principle sensorial correlations can be made.

Trigger
load used to determine when probe has made contact with sample surface.

Visco-elastic
materials which cannot be classified as either viscous or elastic and have the properties of both. Texture analysis is used to determine the ratio of viscous element to elastic element.