Towards designing bio-inspired saliva substitute: Does it influence sensory perception?

March 13, 2019

Saliva is important to be able to experience multi-dimensional textural perceptions, such as creaminess, smoothness, astringency etc. Therefore saliva-mediated lubrication has gained significant attention in the food research community to develop a suitable saliva substitute.

Unfortunately, about 10% of the general population and 25% of older people suffer from dry mouth (Xerostomia), meaning they do not have enough to almost no saliva. This may be due to prescription medications, radiotherapy, and certain autoimmune diseases. Also, age can influence the quantity and quality of saliva. Lack of saliva can result in severe eating difficulties with a reduced sensory appreciation of food. Although a range of commercial saliva substitutes are available on market shelves, they are sub-optimal in reproducing the hydration and lubrication properties of saliva. Renewed research interest in more effective saliva substitutes is driven by the increase in elderly population with chronic diseases and polymedication that commonly induces mouth dryness, which adversely affects the sensory appreciation of food. This, in turn, can lead to reduced nutrient intake and consequently malnutrition.

In this research, we utilised a rational and innovative combination of biopolymers to design a bio-inspired saliva substitute that replicates the lubrication property of real human saliva. We used a combination of complementary techniques, such as adsorption techniques, electron microscopy, tribology at multiple length scales and wettability measurements to confirm the unique properties of this bio-inspired saliva substitute.

Work is ongoing to understand how this bio-inspired saliva substitute can influence sensory perception. Our results will inform the commercial development of this saliva substitute that will enable people suffering from dry mouth to have sensorial pleasure while eating. The University of Leeds is leading this project on Oral Processing & Tribology funded by European Research Council (ERC), with a particular interest in the fundamental understanding of aqueous lubrication of thickeners and hydrogels to replace fat in future foods without compromising the sensory appeal.

If you would like more information or would like to discuss this research further, please contact Feng Xu. Find one of her published journal articles here.


Each year EFFoST and Cargill present the student of the year award to six students and also give them the opportunity to showcase their research. In this article, Feng Xu who won the 2nd prize for the MSc student of the year award discusses her research.  Feng obtained her Masters in Science for the research she conducted under the supervision of Dr Anwesha Sarkar at the University of Leeds. Currently, she works for Bakkavor UK and China as a product developer.