Two samples of instant, dehydrated, mashed potatoes were submitted to Food Technology Corporation for texture evaluation. One product was labeled Control and the other Pasty. The product was prepared based on the recommendations from the customer. For the testing we used a Model TMS-Pro with a 100 Newton load cell and a 75 mm diameter compression platen
10 gram samples were placed directly on to the base table.
Each sample was compressed to a distance of 5mm from the base plate at a speed of 200 mm/min.
The compression plate was then held for 3 seconds before retracting up at 500 mm/min.
The 3 second pause was to give the sample time to stick the compression platen to highlight the pasty/sticky attribute of the samples.
After testing was completed, we compared the work or “area under the curve” of the retraction stroke. Typically to measure a sticky/pasty characteristic, we look at the maximum negative force and / or the negative area (work to retract the platen). This gives an indication of how the product resists pulling away from the compressed state. A sample that requires more force/work is stickier/pastier than one that requires less. Care must be taken to get consistent results as temperature, operator, batch, prep, etc. will affect the final results.
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Work
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Units
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N.mm
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Units
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N.mm
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Pasty 1
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49.0
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Control 1
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15.8
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Pasty 2
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47.9
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Control 2
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14.9
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Pasty 3
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43.3
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Control 3
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12.0
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Average
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46.7
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Average
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14.2
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Conclusions
This method of testing gave repeatable and consistent results for product that was considered pasty or sticky verses a control sample. For other textural parameters related to a product such as this, other techniques will probably be required.
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