The research – published in Food & Function – reports on an investigation into how salt from potato crisps is released and perceived in the mouth. Researchers from the University of Nottingham, UK, measured the ‘saltiness’ of crisps using measures of sodium in saliva and sensory test panellists.
Dr Ian Fisk and Tian Xing, from the University of Nottingham, found a large proportion of the salt in crisps is released around 20 seconds after chewing – at which time the crisp may have already been swallowed.
"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,” said Fisk
“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," he explained.
The food scientists said the idea could increase flavour but use less salt, leading to new ways of producing healthier crisps — without impacting taste. They said the research could be applied to other areas of food science and may perhaps lead to significant salt reduction in all snack foods.
Sodium is a vital nutrient and is necessary for the body to function. However the average daily salt consumption in the western world (between 10 and 12 grams) vastly exceeds maximum recommendations from WHO/FAO of 5 grams per day.
Such high intakes of dietary sodium have been linked to negative health impacts, including the development of hypertension, cardiovascular disease, certain cancers, and other health problems.
In countries like the UK, Ireland, the USA, and other industrialized countries, over 80% of salt intake comes from processed food – meaning many do not realise they are consuming such high quantities. Because of this, reducing the sodium content in food products has become a major issue for the processed-food sector.
The process of reducing salt levels in foods is an ongoing process within the industry, with many now acknowledging that high sodium levels in some foods is a major issue for the industry.
However, the reduction of salt in processed foods is a major challenge because in addition to salts role as a flavour enhancer, the food industry has historically added salt (sodium chloride) to foods to enhance shelf life, modify flavour, enhance functionality, and to control fermentation.
“There is a clear need for the food industry to identify technical routes to enable functionality to be modified, flavour to be enhanced, and shelf life to be preserved, whilst reducing the concentration of sodium salts and maintaining the consumer experience,” said Fisk and Xing.
Fisk and Xing asked a panel of food testers to chew a crisp a prescribed number of times and hold it in their mouths for 60 seconds. The team monitored the salt level in the mouth throughout the tests by taking tongue swabs and analysing them.
They detected that sodium levels peaked at around the 20 second mark, whilst the trained panellists confirmed that they too sensed a significant increase in salt at around this time.
Fink explained that the release of salt is “complicated because the salt sits on both the crisp's surface and is embedded in the surface oil.”
The researchers will soon begin a research project (working with a range of food companies in the UK) to help them develop effective salt reduction strategies and to solve technical problems surrounding salt reduction.
Source: Food & Function
Published online ahead of print, doi: 10.1039/C2FO10282J
“Salt release from potato crisps”
Authors: X. Tian, I.D. Fisk