Presentation Details
Salivary Protein Response to and Recovery from Cranberry-derived Polyphenol Exposure: Methodological Insight From A Time-Course Study

Neeta Y Yousaf1, Melania Melis2, Mariano Mastinu2, Cristina Contini3, Tiziana Cabras3, Iole T Barbarossa2, Beverly J Tepper1.

1Department of Food Science and Center for Sensory Sciences and Innovation, Rutgers University, New Brunswick, NJ, USA.2Department of Physiology, University of Cagliari, Cagliari, Italy.3Department of Biochemistry, University of Cagliari, Cagliari, Italy

Abstract


Astringency is a tactile sensation which is often experienced when dietary polyphenols interact with salivary proteins. Although it is standard practice in astringency research to provide breaks in between stimuli, there is limited consensus over the amount of time needed to restore the oral environment to baseline levels. Here we examined salivary protein levels after exposure to 20 ml of a model stimulus (cranberry polyphenol extract, 0.75 g/L CPE) or unsweetened cranberry juice, CJ over a 10 min period. Whole saliva from healthy subjects (n=60) was collected at baseline and after 5 and 10 mins following either stimulus. Salivary proteins of five families (basic proline-rich proteins (bPRPs), acidic proline-rich proteins (aPRPs), Histatins, Statherin, & Cystatins) were identified from whole saliva by HPLC-ESI-IT-MS and quantified using the area of the extracted ion current (XIC) peaks. In comparison to baseline (resting), both stimuli caused salivary protein levels to rise, although CJ elicited a more robust response than CPE. Levels of all proteins (except two bPRPs) rose after stimulation with CJ, remained high at 5 mins (p<0.0007-0.0001) and did not return to baseline even at 10 mins (p<0.05-0.0001). In comparison, CPE increased the levels of aPRPs, and selected Cystatins & Histatins (p<0.04-0.0099) at 5 mins, which generally did not return to baseline even at 10 mins. Differences in bPRP levels with respect to gender and PROP taster status were observed after stimulation with both CJ and CPE. These data show that the oral environment may need more than 10 minutes to reset after an astringent stimulus, which is far longer than the typical break used in sensory studies. These findings will inform sensory methodology and will be discussed in the context of interindividual differences.

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