To the bitter end

To make functional foods - often bitter or poorly tasting - palatable, the flavourist is charged with somehow disrupting the system, to make the consumer unaware of any off notes.

There are two methods commonly used to do this. One is to 'confuse' the palate by working with flavours already present. For example, flavours with bitter notes, like chocolate, can disguise unpleasant bitter-tasting ingredients. Although the bitterness remains, it is associated with the chocolate rather than the functional ingredient, and is therefore accepted by the palate.

Synergy has used this method extensively in partnership with whey protein supplier and parent company, Carbery. Whey protein is used in sports, clinical and infant nutrition and is also used in functional foods. It's a classic example of where taste masking is essential to bypass bitter notes.

Many users of whey protein mask its bitterness with vanilla, chocolate, coffee and caramel flavours, whose smooth, round notes offset the taste of the protein itself. The other major group of flavours used in whey protein applications is fruit. Here, the natural acidity of the fruit, such as malic acid (the apple's primary acidulant) or citric acid (prevalent in strawberries), deceives the senses into associating the bitterness with the fruit, rather than the protein.

The other common taste masking method is to 'block' bad taste by adding to or modifying levels of ingredients in the base formulation. This is often achieved with acid, salt and sugar. However, the demand for healthy, natural products means such ingredients often receive bad press. For this reason, the search is on for natural options to provide the desired taste without causing concern over labels.

A number of plant extracts have been identified as being able to mask off notes and improve mouthfeel. Yerba Santa, for example, contains four flavanones that have bitter masking properties - homoeriodictiol, naturally occurring sodium salt, eriodictyol and sterubin. Conventionally used to offset the bitterness of medicines, Yerba Santa has the potential to do the same in functional foods, providing manufacturers with a natural ingredient that can help ensure consumer enjoyment.

Certain molecules are known to work well in particular situations. Glycerine, for example, is often used as a carrier for flavours, but it also helps smooth the base and offers slight masking effects.

The reasons why certain molecules are effective at masking bad taste are, as yet, unknown. Molecular research is in the early stages, investigating the chemical make-up of flavours and the effects they have on different substances. Studies into off notes are also underway, to discover why they occur and how best to overcome them. Carbery, for example, is working with universities on research into the bitterness in whey protein.

For now, the skill of the flavourist is essential to help make products consumers will accept. But by understanding the molecular workings of flavours (pleasant and unpleasant), companies like Synergy and Carbery are developing a more technical approach to taste masking, transforming the art of flavouring into a science.