"Developing a reduced calorie product is not a simple task because fat, carbohydrates and proteins are essential for the overall taste. Calorie reduction impacts not only the mouthfeel but also the aroma and taste of the product. This means that the complete experience or perception of the product can change when the fat, carbohydrate or protein levels are altered," she says.
Taking fat first of all, Calatayud explains that when the content of this macronutrient is reduced, it impacts on aroma release, and therefore flavour perception.
"When fat is reduced, the release of aroma can change drastically. This happens because fat is a carrier of fat-soluble aroma compounds. When fat is reduced, the balance between the food matrix and the aroma compounds is no longer in place," she says.
She uses the example of ice cream to illustrate how upsetting the balance between the aroma compounds and the food matrix affects flavour perception.
"A full fat ice cream will seem less sweet than a reduced fat version containing the same quantity of sugar or other sweeteners. This is because the fat balances the aroma and taste. By reducing fat, the balance is lost and the sweetness has a higher impact."
UK flavourist Create Flavours is delving even deeper into the interactions between dairy systems and flavours, carrying out a 12-month project exploring the synergies between specific flavour molecules in fruit flavours and dairy products. The aim is to develop a fruit flavours range with increased acceptability in reduced fat dairy products.
"The challenge was to identify which flavour compounds were important to the flavour of dairy fats and then incorporate these compounds into specific fruit flavours," explains Jonathan Jones, md of Create Flavours.
He says the key to this is understanding the inherent flavour characteristics of specific fruits and anticipating how various molecules will impact on the flavour.
"For example, a product developer may want to impart a fresh strawberry flavour in a reduced fat yogurt. Buttery characters can be very important in the flavour of cooked strawberry, and these same characters are often desirable in dairy systems, so we're looking at how you can increase the buttery character in a low fat system while avoiding cooked strawberry flavour."
It's not just dairy products where fat reduction removes flavour. Jones says he has carried out work looking at meat flavours. The project involved using solvents to defat lamb, beef and chicken, and conducting organoleptic analysis of the defatted meats.
The results showed that the fats were the primary flavour contributors and that in meat products not only do the fats possess their own individual flavour characteristics but they also act as carriers for aroma compounds generated through the cooking process.
It is clear that removing fat removes flavour, but what can be done to restore the flavour of reduced fat products?
According to Symrise, the solution lies in bringing back the mouthfeel of the missing fat and rebalancing the flavour profile.
"It is through sensory analysis, the creation experience of our flavourists and our SymLife Taste Modulation solutions that we can recreate the balanced profile," says Clothilde Croixmarie, global competence director taste modulation with Symrise.
Specifically, SymLife Cream is a range of natural and nature identical flavours designed to enhance creaminess perception.
"It is a mouthfeel flavour system that helps to rebalance fat reduced products where taste and body are missing," says Croixmarie.
Comax Flavors, meanwhile, says it has had success formulating products with its Mouthfeel flavour, which is said to lend body and fullness to reduced fat products. The US-based flavour house has also developed butter, cream and milk flavours that replace dairy fat in a variety of products.
For Givaudan, the starting point is Sense It Mouthfeel, a language which provides a visualisation of the mouthfeel experience and description of the flavour, taste and mouthfeel of products. It says this, coupled with flavour technology and knowledge of reaction technology, enables it to build back certain mouthfeel characteristics of high-fat foods, with less fat.
With salt reduction efforts now underway across Europe under the EU framework for national salt initiatives, reduced salt reformulation is another big challenge for flavourists.
However, it seems consumers haven't been overly impressed with the food industry's salt reduction efforts so far.
"Our customers tell us that consumers are increasingly dissatisfied with the taste of products that have been formulated, or reformulated, with lower salt profiles," reports Roland Wientjes, applications director, Kerry Ingredients & Flavours, Europe, Middle East and Africa.
It's not surprising food manufacturers are struggling. Salt reduction is, after all, complex, as Silke Ortmann, product manager at Wild, explains: "When salt is reduced it's not a simple task of taking it out and replacing it with something else, rather it's a complex reformulation involving acidity, flavour profile and saltiness. Therefore all product formulations prove difficult, especially when it is a brand with which the consumer has formed a strong taste relationship."
According to Givaudan, it is relatively simple to remove 5–10% salt from a product simply by increasing the percentage of other flavours. Calatayud says Givaudan can go beyond these reductions and in some applications achieve over 50% reduction while maintaining great taste.
As with fat reduced products, the company's sensory language, in this case Sense It Salt, provides the starting point for reducing salt. Givaudan says its understanding of the physiological response to salt has also helped it develop alternative ingredients that invoke the same response.
"For instance, our TasteTrek Umami revealed new classes of natural taste modulating molecules which we are now using in low salt applications," says Croixmarie.
Symrise's SymLife Salt concept encompasses two approaches to developing reduced salt foods. It refers to the first as "intelligent reduction", which draws on consumer insights, sensorial experience and flavours expertise to create an "optimised product and flavour concept".
The second approach works with flavour modifiers. This could involve the use of flavours to boost salty taste, masking of bitter substances such as potassium chloride or solutions that help shape the taste in topical applications, such as crisp seasonings.
A key component of the salt reduction solutions offered by Kerry Ingredients & Flavours is FMT, or flavour modulation technology. This is a range of products designed to modulate the perception of taste in products reformulated with less salt, sugar and fat.
Comax Flavors offers salt enhancers and blends for use with salt substitutes such as potassium chloride and potassium lactate.
"They can mask the bitter taste associated with potassium, as they enhance the saltiness inherent in the food product. They also have the power to enhance the umami taste [a basic taste associated with savouriness] of food," says Comax applications manager Gladys Slovis.
A lot of flavour companies, Comax among them, have steered clear of developing salt substitutes, focusing instead on salt enhancers and maskers. Wild, however, has gone against the grain, with SeaSaltTrim, a sea salt containing low levels of sodium and high levels of potassium chloride. To mask the bitter-metallic potassium note, Wild combines the sea salt with a natural flavouring.