Measuring the noise of bread roll crusts

Crustiness is an attribute increasingly sought by consumers, who now enjoy an unprecedented range of international bakery products, including baguettes, ciabattas, focaccias and crusty bread rolls.

A dry, crusty outer texture and a crispy sound are an essential part of the eating experience, which can now be measured repeatably and objectively. Zeelandia, a global bakery ingredients manufacturer, has pioneered an exciting new testing method to determine the crustiness of bakery products using market-leading texture analysis equipment.

Combining Stable Micro Systems’ bread ‘V’ squeeze test with simultaneous acoustic measurements, Zeelandia obtains detailed objective analysis of crust breakage. This enables the company to develop high-performance ingredients that respond to a dynamic and growing sector of the bakery market. 

The new test combines the use of a microphone with a bread ‘V’ squeeze attachment with a Stable Micro Systems TA.XTplus texture analyser. The ‘V’ squeeze attachment comprises two ‘V’ shaped rounded fingers which are lowered onto the sample and squeeze it for defined period of time, or to a specified distance. The Exponent texture analyser software measures the force required to compress the sample and the sounds emitted as compression takes place. The higher the force reading and acoustic emissions, the crustier the product is deemed to be.

Henk Mulder, physical scientist at Zeelandia, comments: “Stable Micro Systems’ equipment is extremely accurate and versatile. Manual tests, and even our previous lab testing methods, didn’t give us enough detail to draw meaningful conclusions for our NPD or quality control purposes. The ‘V’ squeeze test measures valuable parameters, but recording sound using the Acoustic Envelope Detector provides far more detailed results that can be used in new product development and for competitor analysis and QC purposes.”

Coen Sander, food scientist at Zeelandia, adds: “Perfecting texture in crusty products is particularly challenging because despite the crunchy crust, we’re often also seeking a soft centre – all with maximum shelf life.

"We’re now testing a wide range of finished baked products containing different Zeelandia ingredients in varying proportions. Collating and comparing these detailed test results means we can evaluate the impact of changes to recipes and processing conditions.”

Conny van Loon, sales manager at Stable Micro Systems, sums up: “This is the latest example of a Stable Micro Systems customer developing bespoke tests to respond to its own needs, and those of its market. “Zeelandia can now offer its customers even more valuable technical support, as well as continue improving its own product offering.”