Salt smell can trick the brain into enjoying low-sodium food

Posted by Nicole Eckersley on 13th April 2011

Food giant Unilever’s scientists have found a new way to reduce salt from people’s diet – by tricking their brain into thinking food is saltier than it really is.

The company said the breakthrough findings could pave the way for improved consumer health, by allowing tasty products with a lower salt content. Excess sodium intake has been linked to serious health problems such as hypertension and cardiovascular disease.

The scientists found that they could enhance people’s perception of the saltiness of their food by giving it a smell which they associated with salt.

“For several years we’ve worked hard to successfully reduce the salt content of our food products, but it’s always a delicate operation to ensure that consumers don’t ultimately turn their back on them because they don’t like the new lower salt taste,” said Johanneke Busch, Unilever Food Scientist.

“This is an exciting discovery because it might just point us to the answer to this age-old problem. If we can reduce the salt content of our products without impairing their taste, we’ll make a significant contribution to improving the health of our consumers.”

In this study, experiments were designed to understand whether people’s perception of the saltiness of food could be affected by their sense of smell, even though salt itself does not have an odour.

Participants were asked to rate the saltiness and taste intensity of cheese cubes which had each been flavoured with a different but tasteless aroma. The first two aromas were associated with common foods with a high salt content, while the third cube of cheese was flavoured with the non-salty smell of carrot. All three samples of cheese contained the same amount of salt.

The research found that participants rated the cheese which had been flavoured with sardine or comté cheese odours as significantly more salty and taste-intense than the cheese in its original state. However, the cheese which had been flavoured with carrot odour was reported to taste less salty than the original.

The Marmite to Magnum consumer goods company now plans to use this finding to reduce the salt content of its famous brands.

As part of the Unilever Sustainable Living Plan, the company’s ambition is to help consumers meet the recommended level of 5g of salt per a day – based on globally recognized dietary guidelines – by reducing the salt levels in its products by a further 15-20% by 2015-2020, depending on the country.

Unilever has already significantly reduced salt levels in its products, such as in its Knorr soups and sauces. Between 2003 and 2010, up to 25% of salt has been reduced in its food products without affecting their taste or cost.

The research, which has been published in the International Dairy Journal, was carried out in partnership with the University of Bourgogne, Dijon.