Stable Micro Systems has developed a Multiple Puncture Probe whichaccurately quantifies the firmness of foods with variable textures, from fruit and vegetables to thick-cut marmalade and chocolate chipice cream. Using several testing pins, attached to the TA.XTplus texture analyser, food manufacturers can test non-uniform products containing particulates of different size, shape, structure and levels of hardness, to provide repeatable results.
Testing diverse elements within one product, such as ice creamcontaining randomly-distributed fruit chunks, is not only tricky butoften results in low reproduceability and misleading data. It may showwide variances between maximum and minimum force resistance, dependingon whether the probe reaches a piece of fruit or ice-cream first.
By penetrating the product in several areas at the same time, Stable Micro Systems claims that the Multiple Puncture Probe produces an averaging effect and is therefore more representative.
The company claims that the testing method also greater offers flexibility. When forces are created above the capacity of the load cell being used in the TA.XTplus texture analyser, the operator can adapt the test by removing pins and reducing the contact area, if necessary. However, the more probes that are used in the test, the more reproduceable the results.
Other innovations recently launched by Stable Micro Systems include a new constant strain inflation rate facility that enables manufacturers to alter the inflation rate of the dough bubble as its volume changes. Evaluation of the dough bubble's large deformation extensional properties provides vital information on the stability of gas cells and gas retention during proving and baking - key factors in the structure and volume of the final product.
Dough stickiness testing allows manufacturers to quantify the effects of overmixing, addition of excess water, overactivity of proteoytic enzymes, differences in wheat varieties and composition. Using the Miller-Hoseney toughness rig, the toughness and firmness of breads and other sliceable products can be established. The company claims that many bakers use this test to assess staling and test the effects of ingredients and processes that can improve shelf-life.
Stable Micro Systems believes that instrumental methods of assessing texture rather than sensory analysis tend to be more accurate. They operate under more strictly defined and controlled conditions, and problems of experimental variability are more likely to be caused by sample heterogeneity than by instrumental imprecision.
In addition, changes in ingredient levels can cause simultaneous changes in product characteristics, and some of these changes are difficult to mask. This tends to make sensory analysis difficult - for example cake firmness continually fluctuates depending on sugar content.