Pro Tip: Using Texture analyzers can determine the chewiness, elasticity, and hardness of baked goods, as well as how new ingredients change these properties.
Developing new baked goods requires getting the right flavors and mouthfeel, but these properties can be difficult to quantify. Sensory testing is impractical for every new product formulation, as it can be an expensive and time-consuming process. Texture analyzers are a tool to better understand product mouthfeel, and data from these machines can be used as a part to recommend the best products for further development.
By processing graphs of force, time, and strain from experiments conducted using texture analyzers, it is possible to assign specific numbers to texture properties such as chewiness and elasticity, and these attributes can be obtained in minutes. Texture analyzers have been used in the baking industry to study bread staling or analyze extruded products, and they can help determine how new ingredients change the texture of baked goods in quantifiable ways.
Texture Analyzers are fairly simple in design, yet very versatile in their applications, aided by a number of interchangeable probes for compressing, breaking or stretching dough and finished products.
Figures 1A and B show typical setups for compression testing and three-point bending testing that can be used to study baked goods of different shapes. Figures 1C and D show examples of data that can be extracted from each configuration. In these tests, the texture analyzer moves downward, compressing or breaking the material, and the force (in grams) is recorded by the equipment. Stress is the force divided by the area of the sample. Strain is recorded by the equipment and is the amount of material deformation (movement) as a result of the test, expressed as a percentage.
In compression testing, it is common to perform the experiment twice on the same sample to see how much of the original shape the material recovers after compressing it, while the three-point bending platform breaks the material. For compression testing, values correlated to sensory studies can be extracted fairly quickly from this data, including hardness, elasticity, cohesion and chewiness, as defined below:
Using the three-point bending platform, the most common metric to calculate is the bending stiffness, which is the slope of the linear portion of a stress vs. strain graph (Figure 1D). The maximum force and strain can also be calculated from these experiments.
Texture analysis provides objective numbers on texture properties, which can be useful in product design. For example, if a research team has developed ten variations of a product that include different levels of vegetable protein, the change in chewing can be observed for each level of protein. Using this approach, the level of protein that would be considered acceptable by consumers can be found more quickly than with sensory testing. Texture analysis could also be done during shelf life to see how stiffer the product becomes over time, indicating when consumers may begin to reject new products a team is developing.
Harrison Helmick is a PhD candidate at Purdue University. Connect on LinkedIn and check out his other baking tips at BakeSci.com.
His research is carried out with the support of Jozef KokiniAndrea Liceagaand Arun Bhunia.