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When it comes to chewing gum, sound matters 

March 30, 2015

Sensory characteristics of food – appearance, flavor, texture – are playing an increasingly important role in influencing consumers’ purchasing decisions. They are crucial to each individual’s preferences for specific products, and attributes like chewiness, crispness and mouthfeel have considerable impact on consumer brand loyalty.

Market trends show this is particularly true for the confectionery market: products like candies and pralines are usually consumed mainly for their rewarding, pleasant sensory characteristics. However, many other factors come into play when producing confectionery products. Topical concerns range from cost optimization to healthier formulations, and today’s food manufacturers need to be able to deal accurately with elements which have an impact on sensory characteristics.

A major challenge facing food developers is how to accurately and objectively measure parameters such as mouthfeel or crunchiness. Mouthfeel is a composite property related to a number of physical properties, and their relationship is complex. Describing crunchiness in an accurate, scientific value had proven difficult, but a new Cargill solution is challenging the status quo.

Soundscapes of crunchiness

Cargill’s expanded sweetness portfolio is backed by the company’s application centers, such as its state-of-the-art European R&D center in Vilvoorde, Belgium. Recently expanded to include 5,000m² of pilot facilities, the center is an innovation space used to develop new ingredients, innovative reformulations and test new manufacturing processes.

Bart Cortebeeck has been working there as a confectionery application specialist for many years, studying ingredients’ synergies, developing new concepts or optimizing customers’ existing formulations. By observing the current measuring methods, he developed one of the first significant systems for scientifically classifying the level of crunchiness of chewing gums’ external coating.

“Consumers like to hear and feel a ‘crunch’ when they bite into coated confectionery products,” explained Cortebeeck. “The crunch is a combination of auditory and tactile sensation. In that sense, crunchiness is different from hardness. Hardness is a purely physical characteristic of the product as the product is bitten into, whereas crunchiness is related to brittleness. Typically, the harder and more brittle a coating, the crunchier.”

At the same time, coating hardness (also called firmness) is the resistance perceived as the coating is chewed, and does not necessarily relate to crunchiness. The hard coating creates texture differences from a soft or chewy confectionery center. Ingredients in the coatings are quickly broken down during chewing and help create a burst of flavor, cooling, or sweetness.

“I have been working on confectionery applications for many years,” said Cortebeeck. “While working to develop several new solutions for gums, I realized that a scientific measurement specific for crunchiness was missing.”

Cortebeeck developed a new classification of crunchiness levels based on mechanic principles that could be monitored by the new instrument-based measuring method. This has allowed Cargill to develop its very first Coating Toolbox. The toolbox is a service provided to customers, by which we analyze their products’ on different parameters. These parameters — coating time, crunchiness, stability — give the opportunity to benchmark ingredient performance and match them to the specific customer needs.

The method

Together with Stable Micro System, a company that develops and supplies texture analysis and powder characterization equipment, a new hardness-measurement machine was developed. Using a highly sensitive microphone, the machine is now able to record the slightest noise when the product is being tested.

When crispy or crunchy foods, such as gums or crisps are crushed through chewing or mechanical testing, unique sounds are emitted by the brittle fracture of the product’s coating. These noises play a major role in determining the consumer’s perception of a product.

“The machine’s results make it easier and more accurate to compare the performance of coating formulations obtained with different ingredients,” explained Cortebeeck. “We succeeded in getting repetitive results, proving the reliability of this method across a range of applications.”

For customers, accurate texture testing offers genuine benefits. “Whether customers are focusing on a shorter coating time, higher product stability, or marked bulk and texture, we can use this method to devise the ideal blends of sweeteners and polyols to achieve the desired effects, with an accuracy never dreamed before,” he said.