U. NOTTINGHAM (UK) — Measuring how we taste potato chips’ saltiness could lead to reduced sodium but not lost flavor.
The University of Nottingham research, published in the journal Food & Function, follows an investigation into how salt is released from chips into the mouth. Though focused on chips, the research is relevant to salt reduction in all snack foods.
Ian Fisk, a lecturer in the division of food sciences, says: “The ‘salt burst’ from crisps is only released into the mouth 20 seconds after chewing begins. This means that in many cases the crisp may have already been swallowed before the majority of the salty taste is detected.
“Our aim is to develop a series of technologies that accelerate the delivery of salt to the tongue by moving the burst from 20 seconds to within the time that you normally chew and swallow. This would mean that less salt would be needed to get the same amount of taste.”
Excess salt in the diet has been linked to high blood pressure and cardiovascular disease. The World Health Organization’s recommendation for daily salt intake is just five grams, though many people take in twice that amount. The reduction of salt intake is now a major challenge for health authorities and the food industry.
Why is salt in our food?
Salt isn’t just a flavor enhancer. Historically it has been added to enhance shelf life, improve functionality, and control fermentation. Breads, snacks, and potato chips are among the major dietary contributors to our salt in-take.
There is now a clear need for the food industry to find ways of preserving these attributes while maintaining the consumer experience.
Crisps tasted under strict supervision
Salt release is complicated and the panel of ten tasters was chosen for their ability to eat repeatedly ‘under instruction.’
Working with student Xing Tian, Fisk brought together the consumer panel of food tasters to chew crisps a prescribed number of times and hold them in their mouths for 60 seconds. The crisps were then swallowed as usual.
By taking tongue swabs and analyzing the results on equipment capable of detecting sodium content, they were able to monitor the salt levels as they peaked and troughed. Unlike other studies, Fisk’s research identified the moments of maximum intensity and maximum value.
Salt in chips sits both on the surface and is embedded in the surface oil. So the salt has to be physically separated from the crisp bolus (chewed material), solubilized in the saliva, and then moved to the salt receptors in the tongue for the brain to register the taste before being swallowed.
“After 20 seconds we detected a peak in saliva salt concentration. The panelists confirmed that they too detected an increase in salt perception at around this time,” says Fisk.
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