Mushrooms (Canned) Firmness Effect of Salt


A producer of canned mushrooms uses simple subjective measurements to evaluate the final texture of their product. The information is often used to make adjustments to the process. Their real need, however, is to obtain objective data that represents the sensory evaluation. Our example here demonstrates how this can easily be done using a food texture analyzer. For the particular test, an unsalted (control) product and a low-salt equivalent were compared.






A Food Technology Corporation (FTC) TMS-Pro Texture Analyzer was fitted with a 2.5 kN intelligent loadcell, along with a Kramer shear compression cell. This type of test cell is designed for testing products in a bulk form instead of small samples, compressing and extruding the contents with multiple blades. This method of testing generally produces more consistent results than simple probe or plate compression, achieving average texture values across the bulk sample. Each test used a whole can of drained mushrooms, which was allowed to stand for 90 seconds before being added to the shear cell.

The TL-Pro control and analysis software was programmed to move the blades of the test cell down at a speed of 250 mm/min to a distance far enough to ensure that the product was completely expressed through the bottom of the test cell. On completion of the test cycle, the software automatically calculated the peak force of compression or ‘firmness’ of the sample. In addition, the work done (energy spent, or area under the curve) was calculated as an additional defining factor.



The graphical representation from TL-Pro, of the test results for the four samples, is shown here (force applied, against cumulative displacement).

The control and salted samples show no great distinction, there being no clear division of groups of traces. Lines cross, but generally with a greater peak force found in the unsalted samples, showing that firmness can increase at greater compression and extrusion depending on the product formulation.

The same results with additional calculations are shown here.

  • Average = arithmetic mean
  • SD = standard deviation
  • CV = coefficient of variation: (SD/Mean) x 100



Consistency in the results demonstrates that this method of testing is reliable, repeatable and detailed. Peak values over bulk testing are a valid and useful comparison. Firmness in itself may, however, be variable across the test, since shear is taking place, not just compression. The energy expended in completing the cycle could provide a more useful comparison figure, as may firmness at specific displacements. What we have demonstrated, however, is that objective and detailed data are available with computerized texture analysis that cannot be obtained any other way. These data provide an invaluable way to compare product formulations against subjective evaluations of what is a desired texture experience, and then to automate testing for acceptability.

Trusted by customers across the world

The University of Arizona’s Nutritional Sciences Food Lab acquired a Texture Analyzer from Food Technologies about 5 years ago. The company has a great product, which is tailored to food needs. 

We have used the Texture Analyzer for both research projects and as a tool to demonstrate to students how food manufacturers can employ objective testing in product evaluation to show how differing ingredients in the same product can affect quality attributes. Its use adds another dimension to the foods labs.

Drew Lambert has been instrumental in helping with set up for testing and providing support whenever there’s a question. He has been a pleasure to work with and is always accommodating with our needs and schedules.  He has even sent us special attachments for special projects.  We couldn’t ask for a better technical support.  Thanks for a great product and great service.

Patricia Sparks, Ph.D.
Assistant Professor of Practice

Service, equipment and people are all first class with Food Technology Corporation.

Questions and problems are handled quickly, which is something that is hard to find in today’s business environment.




David Smith, Riviana Foods Inc.

I have been working with FTC for the past 3 years, we bought in that lapse of time 2 texture analyzers with different probes fixtures for all kind of applications at our Monterrey Plant. We have always been able to count on the technical support of FTC who kindly answers our requests in a prompt manner and with the best disposition.

As we continue developing our process to achieve better results at our company, we will for sure rely on FTC for technical support and equipment upgrades that will deliver us the best possible results.

Claudia Rojas, Hershey Monterrey Plant - Mexico
Asst. Staff Scientist