Compression is one of the most common tests done on food products. Typically a sample is placed on a flat surface and an upper compression platen is lowered into the sample. For a true compression test, the compressed sample is never smaller in diameter than the two compression platens. Test are performed by compression to a given force, a given position or a percentage of the original height of the sample.
TPA or Texture Profile Analysis, is a specialized derivative of compression testing. TPA consists of a 4 step test of compression, relaxation, recompression and then a final relaxation. A set of mathematical equations are then used on the resulting data to arrive at numerical values of such texture attributes as hardness, cohesiveness, springiness and chewiness. Compression testing can also be useful in measuring the adhesive or stickiness of the product. It is common in stickiness measurements to compress to a preset degree, hold the position for a given amount of time, and then pull back up quickly to accentuate the adhesive result. Compression platens come in many different sizes and are made form various materials such as stainless steel, aluminium and plastics. Selection of the proper variant depends upon the product and the test sample's geometry.
SGEARING TESTING is a very popular test 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.
There are many different variations on the basic shear testing apparatus such as razor blades, V shaped blades, rounded blades and straight blades. We also offer a wire shear test cell for softer product like cheese and butter. Some versions such as the Warner-Bratzler meat shear design are somewhat standardized toward a particular type of food.