Astringency Perception and Heritability Among Young Finnish Twins

The genetics of astringency perception and the contribution of astringency to the pleasantness and use frequency of phenol-rich foods and beverages were studied in a Finnish twin cohort of young adults (aged 22-25 years). A total of 194 participants (96 males, 98 females) comprised of 81 full pairs (24 monozygotic, 57 dizygotic) and 32 twin individuals without the co-twin participating. Pleasantness and intensity of an apple juice with added tannic acid (TA juice; 1.5 g/L) relative to an untainted apple juice were recorded. Two saliva samples were collected, the first after 12 h of fasting and the second after the stimulation with TA juice. Saliva samples were characterized by determining the total protein, amylase, proline-rich protein, histatin, cystatin, and mucin contents. Participants filled in questionnaires comprising of pleasantness and use frequency of eight astringent items vs their less astringent counterparts. TA juice was perceived as less pleasant and more intense than the pure apple juice. The relationship between astringency, product pleasantness, and food use were found to be complex. Although astringency influenced significantly the sensory experience of the phenol-rich foods and beverages, the pleasantness and use frequency of the products were not primarily steered by their astringency level. In twin analyses, the first tentative evidence of the genetic variation underlying astringency perception was discovered