Relationship Between Astringency and Chitosan‐Saliva Solutions Turbidity at Different pH

ABSTRACT: The astringency stimulus perceived when chitosan is dissolved in acidic medium and the development of turbidity when the biopolymer interacts with saliva were investigated by sensory and chemical tests. Sensory tests showed a high correlation among the judges as astringency intensity increased when solution pH decreased. Chemical tests measured turbidity development, which decreased as pH increased until pH 4.6. When pH values were between 4.6 and 6.3, chitosan solutions interaction with saliva showed the same behavior, although with a less sharp slope of regression. Both methods demonstrated that the relationship between oral astringency and turbidity could be related to salivary protein precipitation.