The science of taste

Abstract

An understanding and description of our sensory perception of food requires input from many different scientific disciplines: in addition to the natural and life sciences, human sciences, social sciences, as well as the arts each contributes their perspective on what we call taste. For the natural sciences, the key concept is flavor encompassing all physical, chemical, and neurophysiological aspects. For researchers in human sciences, psychology, anthropology, and social sciences, taste is a broader concept related to tradition, geography, culture, as well as social relations. For cooks and practitioners, taste is a multimodal facet of food and the way we perceive and enjoy it. An interdisciplinary symposium on The Science of Taste brought together in August 2014 researchers and practitioners who deal with taste from many different perspectives with an aim to provide a composite mosaic of our current understanding of taste.

In contrast to smell and the olfactory system, for which the 2004 Nobel Prize in Physiology and Medicine was awarded to Richard Axel and Linda Buck for their discovery of odorant receptors and the organization of the olfactory system [1], our knowledge of the physiological basis for the taste system is considerably less developed [2]. Some progress has been obtained over the last decade by the finding of receptors or receptor candidates for all five basic tastes, bitter, sweet, umami, sour, and salty. The receptors for bitter, sweet, and umami appear to belong to the same superfamily of G-protein-coupled receptors, whereas the receptor for salty is an ion channel. The receptor function for sour is the least understood but may involve some kind of proton sensing.

Notwithstanding the prominent status of physiology of taste and its molecular underpinnings, the multisensory processing and integration of taste with other sensory inputs (sight, smell, sound, mouthfeel, etc.) in the brain and neural system have also received an increasing attention, and an understanding is emerging of how taste relates to learning, perception, emotion, and memory [3]. Similarly, the psychology of taste and how taste dictates food choice, acceptance, and hedonic behavior are in the process of being uncovered [4]. Development of taste preferences in children and gustatory impairment in sick and elderly are now studied extensively to understand the nature of taste and the use of this insight to improve the quality of life.

Finally, a new direction has manifested itself in recent years where scientists and creative chefs apply scientific methods to gastronomy in order to explore taste in traditional and novel dishes and use physical sciences to characterize foodstuff, cooking, and flavor [5-8].

Noting that in general our understanding of taste is inferior to our knowledge of the other human senses, an interdisciplinary symposium, The Science of Taste, took place in August 2014 and brought together an international group of scientists and practitioners from a range of different disciplines (biophysics, physiology, sensory sciences, neuroscience, nutrition, psychology, epidemiology, food science, gastronomy, gastroscience, and anthropology) to discuss progress in the science of taste. As a special feature, the symposium organized two tasting events arranged by leading chefs, demonstrating the interaction between creative chefs and scientists.

The symposium led to the following special collection of papers accounting for our current knowledge about the science of taste. The collection includes a selection of opinion articles, short reports, and reviews, in addition to three research papers.

The papers deal with the following topics: the comparative biology of taste [9]; fat as a basic taste [10]; umami taste in relation to gastronomy [11]; the mechanism of kokumi taste [12]; geography as a starting point for deliciousness [13], temporal design of taste and flavor [14]; the pleasure principle of flavors [15]; taste as a cultural activity [16]; taste preferences in primary school children [17]; taste and appetite [18]; umami taste in relation to health [19]; taste receptors in the gastrointestinal tract [20]; neuroenology and the taste of wine [21]; the brain mechanisms behind pleasure [22]; the importance of sound for taste [23]; as well the effect of kokumi substances on the flavor of particular food items [24,25].