In addition to "the commonly recognised basic tastes - sweet, salty, sour and bitter - there is now considerable evidence for the existence of a fifth basic taste, known as umami. This Japanese word, translated approximately as "savoury deliciousness", refers to the quality of foods containing significant amounts of naturallyoccurring glutamate, its sodium salt, monosodium glutamate (MSG), or 5'-ribonucleotides. Umami quality is ubiquitous in cuisines throughout the world. The status of umami as a unique taste derives not just from this quality being perceived as distinct from the other basic tastes, but also from evidence for the existence of both glutamate receptors within the tongue's taste cells, and cells within the brain which respond preferentially to the umami taste. The addition of glutamate to suitable foods aimost always improves flavour acceptability. Recent studies from our lab show that this effect is strong enough to be uninfluenced by attitudes towards MSG. In groups of consumers who generally had negative attitudes towards the use of MSG in foods, preference for foods containing additional MSG was consistently higher than those without added MSG, even when the content of the foods was known. There is increasing evidence that glutamate may act as an energy source, similarly to sugars and fats. Thus, it may be that our preference for additional glutamate in foods reflects the energy value that it provides, just as our preference for sweetness does.