Empirical methods of assessing texture are often challenged by lack of homogeneity or uniformity in samples – a challenge which is almost impossible to approach with fundamental methods. Heterogeneous systems have structural elements that can vary considerably for the same overall chemical composition depending upon how they were created.
Sometimes the sample to be analysed may be of variable configuration or structure from piece to piece, such as breakfast cereal flakes.
In the case of fruit testing, for example, whilst the preferred method of testing might be compression, the inherent variability of natural products and the range of sizes of fruit from piece to piece may preclude the option of testing the pieces one at a time.
On the other hand, a manufactured sample such as a cereal bar, or indeed a natural product such as meat, may have uniformity in its sample shape and size but consist of an entirely variable texture throughout.
These challenges call for a range of tests which deal with the compromise of sample heterogeneity.
