74-09.01 Measurement of Bread Firmness by Universal Testing Machines
The objective of this method is to quantitatively determine the force required to compress a baked product by a preset distance. The firmness may be taken as a measure of freshness and quality. The method specifies only the machine parameters and data calculation method to be used. This method is applicable to research and quality control evaluation of white pan breads. The principle may also be used to study other loaf types and similar products, such as cakes, if sample preparation, indenter size, and load-cell capacities are adjusted appropriately.
74-10.02 Measurement of Bread Firmness—Compression Test
During bread staleness, crumbing occurs. Compression tests are commonly used to measure firmness, defined as the force required to compress the crumb a fixed distance, or to evaluate freshness, defined as the distance a fixed force will compress a crumb. The instrument in this method can be used in either mode. The method is most appropriate for routine daily monitoring in white and light whole-grain breads. The more firm, heavy variety breads may require a different instrument.
74-30.01 Staleness of Bread—Sensory Perception Test
The staleness of bread is evaluated using a structured rating scale with various degrees of intensity of perceived staleness. Analysis of the results provides a quantitative estimate of the differences among bread samples. The estimate of differences is based on an arbitrary scale, reflecting the panel's sensory perception, rather than on actual degrees of physical differences among samples. Sensory panelists must be trained in detecting degrees of staling. It is preferable to use a minimum of 16 judges in the panel.