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Air bubbles may help cut salt and sugar: Unilever

By Stephen Daniells, 11-May-2010

Related topics: Commodities, Cocoa & Sugar

The salt and sugar content of foods may be reduced by using air bubbles as an “inert filler” in liquid products, according to new research from Unilever R&D Vlaardingen.

According to findings published in the Journal of Food Science, addition of air bubbles to a water-based gel enhanced the perception of salt and sugar, and also changed the texture and appearance of the samples.

“It has been demonstrated that the inclusion of air bubbles offers scope for the reduction of sodium chloride or sucrose in food products,” wrote the researchers, led by Johanneke Busch.

Reducing the salt and sugar content of foods without affecting their taste is an important challenge for the food industry. Food manufacturers around the world have voiced their commitment to reducing the quantities of these ingredients in their products, and continue to research new options to offer low salt and sugar versions to consumers.

For the new research, Busch and her co-workers examined the potential of ‘inert fillers’ to enhance taste perception of salt and sugar, meaning less of each ingredient could be used without changing the overall taste of the product.

Water-based gels were prepared using potassium chloride and sucrose or sodium chloride in water and then gelled using xanthan gum (0.5 per cent, Keltrol F, CP Kelco) and agar (0.25 per cent. Deltagar, Kerry Ingredients), and subsequently whey protein isolates (1 per cent, Bipro 95, Davisco Foods). Beating of the gels allowed for the formation of a controlled level of air bubbles up to 40 per cent of the volume.

“It was found that a reduction of the sodium chloride or sucrose by the same weight percentage as the volume fraction of the air bubbles in the samples gave equal taste perception as the nontastant-reduced samples,” wrote the researchers.

“Moreover, saltiness and sweetness perception were clearly enhanced at 40 per cent volume fractions of air bubbles if the sodium chloride or sucrose was not reduced.

“In contrast to previous studies of oil–water emulsions where the oil was deemed to have a mouth-coating effect that reduces taste perception, the air bubbles did not appear to introduce such a negative effect,” they added.

Air may replace fat

“One of the difficulties in using air bubbles as fillers is that the bubbles have to be stable during production or preparation,” wrote Busch and her co-workers. “However, new foam technologies are being developed, which may facilitate the production of stable foams in the future.”

Indeed, scientists from the University of Birmingham in England reported last year that fungal proteins could produce aerated emulsions with the potential to act as fat replacers in foods.

According to findings published in Food Hydrocolloids, the air filled emulsions could reduce the fat content of a food system by 50 per cent.

Furthermore, these three-phase (air/oil/water) emulsions remained stable during storage for 45 days, they said.

Meanwhile, Dutch scientists have developed a new technology to reportedly enable up to 25 per cent reduction of salt in food products without loss of taste or adding other additives.

Professor Rob Hamer, scientific director Top Institute Food and Nutrition (TIFN) in the Netherlands told FoodNavigator at the end of 2009 how their ‘smart salt distribution’ technology works by blending a high salt fraction with a low salt fraction. This creates different layers with different salt content.

“It has to do with the ability of people to measure difference rather than absolute levels,” he explained. “By varying layer thickness we could achieve the sensation of 2 per cent bread, for example, while the actual salt level is 1.5 per cent,” he said.

The same technology may also be applied to reducing sugar content of food products without loss of taste, he said.

Source: Journal of Food Science
May 2010, Volume 75 Issue 4, Pages S245 - S249
“On the Effect of Tastant Excluded Fillers on Sweetness and Saltiness of a Model Food”
Authors: S.M. Goh, B. Leroux, C.A.G. Groeneschild, J.L.H.C. Busch