Determinants of tannin-rich food and beverage consumption: oral perception vs. psychosocial aspects

Diets rich in fruits and vegetables are usually associated with lower risk of metabolic and cardiovascular diseases and cancer. Besides fibre, this has been primarily linked to the presence of polyphenols, including tannins, which have antioxidant properties. However, these compounds also have adverse effects; for example, on the absorption of iron (Fe), and possibly other trace minerals. Food preferences and consumption are determined by a conjugation of diverse factors. Perception at oral cavity level plays a major role in influencing preferences for tannin-rich foods: first, these items are characterised by their production of astringent sensations and bitter taste, which, at higher levels, induce aversion; second, salivary proteins interact with tannins, modulating their post-ingestive effects. Additionally, food choices largely depend on psychological and social factors. Beliefs, habits, values, and past experiences have a major influence on the foods selected. The present chapter aims to review the potential roles of physiological, including sensory and post-ingestive, factors, as well as psychosocial factors, on intake of tannin-rich foods and beverages. The nutritional relevance of tannins, including the principal food and beverage sources of tannins, and the positive and negative health effects, will be reviewed. Focus will be placed on the involvement of oral cavity in the choices of tannin-containing products, including the importance of astringency perception and how such perception is linked to individual oral cavity medium and salivary protein profiles. Finally, and due to the importance of hedonics in the final food choices, psychosocial determinants of food intake in general and of polyphenol-rich food consumption in particular (cognitive, affective, and behavioural dimensions) will be presented.