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Brookfield AMETEK

Mini Pomadoms

Test Principle

Evaluation of the hardness of Mini Popadoms, a thin, pancake-like bread, by bulk compression using an Ottawa Cell.

Background

Using the CT3 Texture Analyser and the Ottawa Cell, the hardness of mini popadoms can be determined and the results displayed in a graphical format. The maximum force value represents sample hardness and correlates with the force required to shear the sample between the molars. The area under the graph from the start of the test to the maximum force value is a measure of work done. This value correlates with the energy required to overcome the strength of the internal bonds within the sample during chewing. The quantity of fractures can also be measured, which gives an indication of sample crispiness/crunchiness; fracturability values are an indication of sample brittleness. Using these textural measurements, the quality of mini popadoms can be assessed to meet customer satisfaction.

Method

Equipment

  • CT3 with 4.5 kg Load Cell
  • Ottawa Cell (TA-OC)
  • Plunger
  • Fixture base table (TA-BT-KIT)
  • TexturePro CT Software

Settings

  • Test Type: Compression
  • Pre-Test Speed: 1.0 mm/s
  • Test Speed: 2.0 mm/s
  • Post-Test Speed: 2.0 mm/s
  • Target Type: Distance
  • Target Value: 30 mm
  • Trigger Force: 30.0 g

Sample Preparation

Remove the sample from the place of storage prior to testing. Weigh the sample into equal portions to enable comparison between tests. Ensure the weighed amount fills the Ottawa cell by at least 60%.

Procedure

  1. Attach the plunger to the instrument.
  2. Fix the Ottawa cell to the fixture base table with the Perspex side facing the front and tighten into position using the side screws.
  3. Place the fixture base table onto the base of the machine and loosely tighten the thumbscrews to enable some degree of mobility.
  4. Slowly lower the arm of the instrument and align the plunger with the Ottawa cell by re-positioning the fixture base table so that the plunger can clearly penetrate the Ottawa cell without any friction effects caused by the plunger touching the side walls of the cell.
  5. Once alignment is complete, tighten the thumbscrews of the fixture base table to prevent further movement.
  6. Raise the plunger above the cell to allow the sample to be placed into the Ottawa cell. Ensure that the sample is evenly distributed within the cell.
  7. Move the plunger down to the chosen starting position (ideally a few millimetres above the sample surface).
  8. Commence the test.
  9. After each test, clean the Ottawa cell to remove all traces of previous sample to avoid variability in the results.

Note: When testing different sample types, the hardest sample is best tested first in order to anticipate the maximum testing range required. This will ensure that the force capacity covers the range for other future samples.

For comparison purposes, the weight of the samples to be tested should be the same from sample to sample.

Results

Figure 1 shows the compression test for 5.4 g of mini popadoms using the Ottawa cell. The maximum force value is a measure of sample firmness/hardness. This is the amount of force required to compress and deform the sample between the molars. The area under the graph from the start of the test to the maximum force value is a measure of work done. This is the energy required to break the strength of the internal bonds within the sample. Tests have been performed at room temperature.

Figure 2 shows force vs. distance for the bulk compression of 5.4 g of mini popadoms using an Ottawa cell. The maximum force value is a measure of sample hardness. This is the amount of force required to compress and deform the sample between the molars. The area under the graph from the start of the test to the target distance point (30 mm) is a measure of work done. This is the energy required to break the strength of the internal bonds within the sample. Once the target distance has been attained, the plunger withdraws and detaches from the sample, as seen by the sudden drop in force to zero load. The horizontal line shows the distance the plunger travels in returning to its starting position (the negative distance values indicate that the probe travelled more than 4mm before contacting the sample).

DISCUSSION

When a trigger force of 30 g has been attained at the sample surface, the plunger proceeds to compress the sample at a speed of 2 mm/s over a distance of 30 mm. During this time, the sample is fractured as seen by the fluctuations on the graph. The maximum peak value is a measure of sample hardness. The area under the graph from the start of the test to the maximum force value (Figure 1) or target distance point (Figure 2) is a measure of work done( energy required to deform sample). Once the plunger has reached the target distance (30 mm), the probe withdraws from the sample and returns to its starting position at the sample surface.

The table below is a summary of the results.

The fracturability and quantity of fractures values are particularly useful when comparing different brands of a sample. Fracturability values are an indication of sample brittleness and the quantity of fractures an indication of the crunchiness/crispiness of the sample. The test can be used to facilitate consistency in production and quality control, optimise the textural attributes of a product, perform shelf-life trials, and predict consumerís perception of a product.