Force Distance Devices Texture Analyzers

1
Force Distance DevicesTexture Analyzers
2
Lab Instruments

• A variety of lab instruments exist that carefully
  control distance and measure force while probing
  a food sample
• These instruments can be fitted with a wide
  variety of probes and fixtures

3
Gardco LFRA Texture Analyzer
4
Stable Micro Systems TA XT2, TA XHD
5
(No Transcript)
6
Instron Corporation
7
Typically, these devices measure force as the
probe is lowered or raised
8
(No Transcript)
9
Compression Tests

• A flat probe is lowered on the sample
• Sample is contained within area of probe
• Measure maximum force, force to break or work
  (sometimes distance) to break used as measure of
  firmness or hardness
• Examples carrot cylinders, cake, gels, rice,
  bread rolls

10
(No Transcript)
11
(No Transcript)
12
Maximum force at compression, or break point
Force
Distance
13
Work is area under the curve
Force
Distance
14
(No Transcript)
15
Penetrometer Probes

• Smaller cylinder is pushed into sample
• Maximum force to reach specified distance force
  at yield point mean plateau force
• Apples, cookies, bread, caramel, cherries, fish,
  fondant, gels, ice cream, peppers, surimi
• Probe may be cylinder, cone, or ball

16
Ball Probes
Magness Taylor Probes
17
Cone Penetrometer Probes
18
(No Transcript)
19
(No Transcript)
20
Snapping Tests

• Measure force required to snap a rigid food
  sample
• Knife edge lowered to a thin food across a
  bending platform
• Bending force generated until material snaps
• Biscuits, cookies, carrot,chewing gum, crackers,
  dry lasagne, pretzels
• Used with snack chips, thin crisp items

21
(No Transcript)
22
Snapping force
Force
Distance
23
(No Transcript)
24
(No Transcript)
25
Extrusion Tests

• Force applied to sample until it flows through
  slots, holes, or annular spaces
• Maximum force to extrude product is measure of
  firmness or tenderness
• FMC Pea Tenderometer
• Viscous materials including some gels, fats,
  peas, catsup

26
Back Extrusion
27
For peas

• ? A-B peas deformed and packed more tightly
• ? B peas packed solid liquid begins to be
  expressed and fill spaces
• ? B-C force increases as juice is expressed
• C-D peas rupture and flow through annulus

28
(No Transcript)
29
Forward extrusion forces material through a hole
30
Forward Extrusion
Back Extrusion
31
Extrusion force inversely related to width of
annulus
32
Larger annulus causes higher force, but more
erratic
33

• Back extrusion
• Peas,mayonnaise, rice pudding, syrup, yoghurt
• Forward extrusion
• Baking fats,ketchup