The Role of Crossmodal Correspondence in Calorie Reduction

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Calorie reduction can be achieved by several different methods. Manufacturers can improve existing low/no sugar formulations or develop new low/no sugar formulations.

Traditional approaches to calorie reduction consist of substituting sugar with artificial or natural high-intensity sweeteners (HIS). However, as the demand for natural low sugar options continues, many consumers are looking for natural sweeteners in the products they buy.

Another option is blending with HIS with low or no calorie bulk sweeteners or use flavours with modifying properties (also known as sweetness modulators) to enhance sweetness. However, it is worth noting that none of these options offers a complete solution to sugar reduction.

How Do We Taste Sweetness?

We have only two sweet taste receptors, made up of two subunits, T1R2 and T1R3, which are activated by different compounds. These send signals to the brain reporting the molecules’ presence. These receptors can be activated by a range of chemically different compounds from sugars, artificial sweeteners to sweet amino acids and sweet proteins. In contrast, we have 25 bitter receptors, this is believed to be because most poisons are bitter and we need a wide range of receptors to detect them and protect us.

Flavour Perception – A Combined Effect

Flavour perception is a complex process. It is a combination of taste, odour and chemesthesis. Chemesthesis is a sensation produced via the touch system that mediates pain, pressure and thermal perception. Flavour perception occurs in the same part of the brain where memories and emotions are regulated, which is why we have the crossmodal correspondence effect. There is a lot of research currently happening in crossmodal correspondence and neurological gastronomy.

Crossmodal Correspondence

Crossmodal correspondence is the systematic associations between different correspondences that are usually unrelated. Shape, weight, noise, colour and music can all influence how food or drink are perceived.

In Western cultures, we associate angular shapes with a more bitter profile and rounder shapes with a sweeter taste. This is known as the kiki-bouba effect, with kiki representing sharper flavours and bouba representing softer, sweeter and rounder flavour profiles. This was first discovered in 1929 by Wolfang Köhler, a German-American psychologist.

In music, there has been lots of research into the effect of music on the flavour perception of wine, in general descriptors of the music can be found to correlate with the wine “powerful and heavy”, “subtle and refined”, “zingy and refreshing”, or “mellow and soft.”

In aeroplanes, the perception of sweetness and saltiness can be significantly lower, hypothesised to be due to the distraction from engine noise. Some people only drink bloody Marys on aeroplanes, is this because the salty, umami character of the tomato juice gives a satisfying taste when other flavours are subdued?

Weight can impact the way we perceive food. Piqueras-Fiszman et al. examined the effect of weight on food. Participants judged yoghurt more dense, intense and expensive when consumed out of a heavier bowl.

Colour can strongly influence how food and drink taste. We expect flavour to be congruent with colour so red beverages should be berry flavoured while orange should be orange. This is a fun experiment to try at home, take colourless flavoured water and add food colouring that doesn’t match the flavour, you will find it much more difficult to describe what it tastes of!

Olfactory Referral

The overlap in neurological processing means we can enhance the perception of tastants with our odour components. Sugar enhances flavour impact, while strawberry flavour has been shown to enhance the perception of sweetness. The aroma of soy sauce also has been shown to increase salt perception. For olfactory referral to be effective, congruency and cultural reference must also be considered as they play an important role in the perception of flavours.

Exploiting Olfactory Referral for Sugar Reduction

Sugar aromas are strongly associated with sweetness and it has been shown that adding an aroma we associate with sweetness, like vanilla, to sugar water makes it taste slightly sweeter. This is only a small effect however, but it is also possible to use a stacking approach and add a sweet aroma to HIS and make it taste much more like sugar.

Treatt Let Nature Do the Work

It is theoretically possible to blend sweet volatiles to increase the perception of sweetness, as in the vanilla example above. In practice this is not the case, the volatiles must be well balanced to give the desired effect. At Treatt, we use naturally occurring sweet foodstuffs to produce our proprietary distillates. Using these natural inputs give a harmonised sucrose or fructose flavour profile which can be adapted to fit the requirements of your beverage.

No-one has yet devised a solution which works as well as sucrose. The best options are a combination of ingredients to give a sweetness profile that is close to sugar and topnoting with a Treatt health and wellness product to give a much more authentic sucrose or fructose profile.

If you’re interested to learn how we can work with you to enhance the perception of sweetness in your formulations, please get in touch at

Written by Charlotte Catignani, Research and Development Manager at Treatt.