Food flavouring with natural and natural identical products: acceptability and nutritional significance

Food acceptability is determined by a variety of physiological, psychological, social and cultural factors; among these palatability, considered as an association of olfactory, gustatory and mechanical stimuli, plays a critical role in food choice. Furthermore palatability potentiates hunger in their common effect of eliciting eating. It has been demonstrated that the addition of non-nutritive flavours to nutritionally controlled diets increases food preference and, generally, that the orosensory characteristics of food per secan stimulate food intake, at least in the short term. Flavouring, for its influence on food choice, seems to affect also some physiological processes. An appetizing meal, for example, can stimulate acid secretion during sham-feeding to a greater degree than routine institutional food, while the action of the taste of food on gastric emptying appears very mild, even if not well documented. It has been demonstrated that after ingestion of an unpalatable meal insulin response was significantly reduced in comparison with a palatable meal; this phenomenon may be related to differences in the early, pre-absorptive or cephalic insulin response. Similarly meals differing in palatability result in different degrees of induction of the metabolic process involved in facultative thermogenesis. Flavouring of food to improve palatability should be studied in order to facilitate the control of food intake; this should be useful in the treatment of obesity by providing low-energy foods that taste like conventional ones, and in the attempt to develop better-tasting foods to stimulate eating in population groups at risk of undernutrition (elderly people, children, etc.).