The Taste of Food

 Eating, sampling and tasting are three activities - despite they all are connectect to food - having completely different goals. The main goal of the act of eating is nutrition, an essential condition which ensures the keeping and development of life. Indeed, eating - besides its most essential role - can also become a disorder or pathology where the food is not considered by the subject for what it really is, such as in case of compulsory eating or disorders related to the rejection of food. In both cases, food is not considered for its nature and its quality: every food is capable of satisfying these disorders or pathologies. The act of eating - as a matter of fact - can also be done absent mindedly, without requiring particular attention saved the essential physical activity, not even the consciousness of what it is being put in the mouth: most of the times other actions having nothing in common with eating are done at the same time, such as walking, reading or watching the television.

 Sampling a food requires a minimum dose of consciousness and attention from the one doing this action. Sampling - that is consuming a small quantity of food in order to evaluate its taste - forces an individual to analyze many qualities in order to understand its characteristics, even though in a pretty approximate way. For example, a food is sampled during its preparation in order to evaluate whether the quantity of salt is enough or to verify the end of cooking. Tasting certainly is more complex because requires a complete attention and consciousness in order to evaluate every single aspect of food - appearance, aroma and taste - and this practice is done during the entire consumption of food, not only to a small part of it, such as in case of sampling. Tasting is always done in a conscious way with the explicit goal of determining and recognizing the qualities and characteristics of a food in its wholeness and in every sensorial aspect: sight, smell, taste, tact and, last but not the least, hearing.

 Taste is a pretty complex sensorial quality and it is the result, among other things, to the perception of fundamental tastes and aromas perceived from the rear side of the nose. The sense of taste therefore involves the sense of smell and without its contribution it is practically impossible to recognize, for example, an orangeade from a lemonade. In fact, when a subject is affected by cold usually believes he or she is not able to recognize tastes. The gustatory qualities of food are usually associated, according to a theory older than one century, to four fundamental tastes, however - as it was widely proven - there is also a fifth taste, today known worldwide with the name umami, discovered in Japan in 1908 by Dr. Ikeda who was successful in isolating this component in Konbu seaweeds. The explanation of umami taste is pretty complex, in particular the way it is perceived by the gustatory sense, however it is absolutely proven it is contained in variable quantities in many foods - including the typical foods of western cultures - where it is still considered skeptically and even discredited, sometimes believed to be cause of some disorders.

The areas of the tongue sensitive to tastes

 The classical theory about the physiology of taste recognizes the existence of four fundamental tastes - sweet, salty, sour and bitter - each being perceived by specific areas of the tongue by means of gustatory receptors, also known as taste buds. The most modern theories - besides having scientifically proven the existence of umami - have also proved that every fundamental taste is detected by the tongue, although the sensitivity to each taste is higher in specific areas. Whether it is true it is simple to explain the taste of the four fundamental tastes, it is pretty complex to explain the one of umami, it certainly is complex to explain to western people because they are not very used to this taste although it has been always present in their foods since the most ancient times. The taste of umami is very evident for eastern people because they have always recognized it and used to enrich and season their foods, such as in case of soybean sauce or the countless sauces made of fish or crustaceans. The main responsible of umami taste is sodium glutamate - usually defined in the west as savor exalter - frequently considered noxious or even cause of disorders, such as the so called Chinese restaurant syndrome.

 This theory - besides having no foundation - cannot even be proven in practice, as many of the foods we usually consume since centuries contain this element in huge quantities and never caused any negative effect. An example is offered by hard cheese and in particular Parmesan cheese - naturally rich in sodium glutamate and other components responsible of the umami taste - which are eaten by many with no negative effects and certainly with extreme satisfaction. Despite it is not our intention to offer a comprehensive and scientific explanations of the umami taste, it is however interesting to recognize its presence and its role in taste and in the agreeability of foods. It is not by chance the most tasty foods are the ones rich in umami taste, such as Parmesan cheese or pizza, as to mention two examples. Recognizing the umami taste is not easy - in particular for the ones not used to it - and as far as this can be useful, it was sometimes defined as a “savory and pleasing taste, similar to the one of meat broth”. A certainly reductive description which however may help to recognize it, after all, talking about tastes - that is about exclusively sensorial and emotional qualities - words do not help that much and provide just a vague idea.

 Things certainly are easier when the four classic fundamental tastes are concerned, whose union, in different proportions, contributes to the creation of taste - and we dare to add to the umami as well - also thanks to the indispensable and precious role of smell. The most sensitive area of the tongue to the sweet taste is the tip, whereas the salty taste is mainly perceived in the middle-outside part of the tongue and just behind the tip. The area of the tongue most sensitive to sour taste is the middle-inside part, towards the center, whereas the bitter taste is mainly perceived in the back part of the tongue. As opposed to the classic theory of taste in which the perception of fundamental tastes is exclusively reserved to specific areas of the tongue, modern researches have proven the perception is possible in the whole surface even though with different sensitivities. The areas usually considered responsible to the perception of each taste are indeed more sensitive in quantitative terms: this makes one believe the perception of a specific taste is exclusively done in a specific area of the tongue.

 Taste - in its wholeness - is the result of many factors and that go far beyond the simple recognition of the fundamental tastes mentioned above. We already said a fundamental role is played by the sense of smell and in particular by the aromas that arrive to the olfactory bulb from the rear, fundamental in order to complete the recognition and the agreeability of foods. However taste is also completed by other factors having no direct connection neither with taste nor with aromas. These gustatory qualities are determined by physical factors of food and by physiological responses according to specific stimuli and conditions. Physical qualities of food allow the distinction - for example - of a beverage or a liquid food from a solid one, therefore recognizing a specific volume and consistency, factors which contribute in a fundamental way to the psychological recognition of a food. For example, if we consider an apple and an apple juice - in which the taste is practically the same - in both we can recognize the taste of apple even though we are aware of the fact it is not the same thing.

 The physiological responses are caused by elements considered irritating or noxious for the oral cavity, therefore the body gets ready in order to react with appropriate defenses. We can, for example, imagine a particularly sour food, such as lemon juice and to the physiological response of the oral cavity. The perception of the sour taste is evident, however this excessive acidity causes a sudden and abundant salivation as the most appropriate defense is dilution. We can also think about other reactions caused by drinking alcohol: the burning and caustic sensation of alcohol cannot be considered as a real taste, however it contributes to the definition of its taste and to its recognition. These characteristics of food, defined as tactile, are generally perceivable in the entire oral cavity, in the palate, in the upper and lower side of the tongue, in the gums and even in the esophagus and in the stomach. Another factor contributing to the definition of taste is temperature of food. This tactile characteristic also modifies the quality and the intensity both of taste and of aromas, such as, for example, the aroma and the taste of fresh baked bread and cold bread.

 The quantities and intensities of fundamental tastes - sweet, salty, sour, bitter and umami - contribute to the definition of tastes that can be considered as in betweens. If we examine a tomato, no one would define this food as sweet or sour. If we analyze its taste carefully, we can discover tomato has a certain sweetness and a certain acidity, even though not in quantity that would make us consider it completely sweet or sour. Despite these primary tastes are nor dominant, they however contribute to the definition of taste, therefore it is always recommended to evaluate the intensity and the strength of every stimulus produced by primary tastes. Practice, curiosity and proper concentration, will let the scrupulous taster to discover that every food is indeed made of all fundamental tastes and in different quantities: it will be discovered, for example, that even in those foods defined as sweet it can be perceived a bitter taste and even a salty taste. In other words, it is recognized as “sweet” a food in which this primary taste is present in pretty high quantities in proportion to all the others.

 Using particular ingredients - such as spices and aromatic herbs - as well as using specific cooking techniques, contribute to the creation of taste. Aromatic herbs - used in cooking since thousands of years - play a primary role on the aromatic part of the food, however they also add their flavors, of which the most frequent is bitter, in particular when are used during the cooking of foods. The cooking technique strongly influences taste because of the chemical alteration of the many ingredients, such as in case of sugar, that from a sweet taste can also get a bitter taste or however slightly bitter. The contribution of the cooking technique in foods is clearly and directly found in taste and in the consistency of foods: the gustatory differences, for example, of raw, steamed and broiled zucchini are common to everyone. Smoking - a technique used to preserve foods - plays a fundamental role in the alteration of taste, even though the aromatic qualities of foods are the most easy to perceive.

 Some tactile properties of food, besides being characteristics for their recognition, play a fundamental gustatory role in order to appear as a dominant quality. Fatty foods are recognized as such thanks to the typical sensation found in the mouth when these foods are being eaten, capable of literally cover the oral cavity therefore diminishing in many cases the perception of fundamental tastes. A pretty similar role is played by unctuous foods - far different from fats because of the different consistence perceived in the mouth - and besides having their own tastes, they also tend to have a pretty evident viscous and slippy action thus altering the perception of tastes. As an example and in order to better understand the tactile sensorial qualities of fat and oils, it can be evaluated the differences of olive oil, butter and lard. Another tactile characteristic that can sometimes modify the perception of tastes is stickiness, typical in jelly and proteinic foods, such as the Italian zampone and other foods made of meat and prepared with particular cooking techniques, such as in the case of stews and braises.

 Among tactile qualities of taste is also found succulence, that is the sensation caused by an abundant quantity of liquids in the oral cavity during the chewing process. Succulence is caused by direct and indirect factors. Direct succulence is caused by liquid substances and juices released by food - including sauces used for cooking - whereas indirect succulence is caused by the physiological reaction of salivation. It is good to observe that every food causes salivation, however specific properties favor a higher secretion, such as in case of sour substances and proteins. tasting food is a complex process requiring total concentration and attention because the factors determining taste are many and work together for its definition. It would certainly be a good habit to always taste food instead of simply eating: in this way not only it is favored the quality of nutrition - and therefore of life - and it would certainly help to avoid many insignificant foods that most of the times have the quality of being eaten with eyes only.