Food shear testing is a very popular method used in food texture analysis. It is common since many foods are first sliced or “sheared” by the front incisors when introduced to the mouth, in addition to preparation, therefore shear fixtures are used to cut the sample.
There are many different variations on the basic shearing apparatus such as razor blades, V-shaped or notched blades, rounded blades and straight blades. Depending on the blade geometry, many actions are performed on the sample, including shearing, tearing and compression.
Some versions such as the Warner-Bratzler design are standardised toward a particular type of food or industry test – in this case meat shear force to measure tenderness. Volodkevich bite jaws specifically simulate the incisors.
FTC shearing fixtures range from heavy-duty blades, developed in conjunction with the USDA, to highly sensitive wires for the ISO butter shear test.
Other products are equally well correlated to consumer sensory perceptions by shear techniques.
NOTE: Shear in this context is a texture testing term – the true engineering definition involves the material shearing within its own structure and is not induced by a fixture which cuts.
Typical Products Tested
- Butter - to measure process quality
- Cheese - to optimise ripening
- Chewing gum tablets - hardness and crispness analysis
- Steak, chicken breast and other meats - to optimise muscle texture
- Confectionery bars - to measure bite profile
- Pasta - for cooking profile
- Pastry - to measure toughness at different formulations
- Sausages - as an indicator of shear toughness
- Snack bars - to measure cross-section
- Vegetables - to optimise heat treatment
- Gel Strength
- Yield Point