Taste Substances

TASTE SUBSTANCES, in the proper sense of the word, are substances which, despite containing no significant amounts of basic nutritional elements, are valuable for our nutrition because, possessing a characteristic taste and smell, they stimulate appetite and make food tasty, pleasant, and thus acceptable for consumption. Tasteless food quickly becomes tiresome and unpleasant to humans; experiments with animals show that they often refuse tasteless feed even when in a state of hunger; for example, dogs and pigs eat meat made tasteless by prolonged boiling with great reluctance. Various plant organs (seeds, fruits, flowers and their parts, bark, leaves and roots), which possess pleasant smell or taste due to the presence of volatile essential oils, aromatic substances, resins and bitter principles, are typical representatives of taste substances in the narrow sense of this term. Such spices, aromatic-bitter substances and bitter substances include mustard, nutmeg, pepper, vanilla, cloves, saffron, cinnamon, bay leaf, ginger, etc.; this category also includes various sharp substances (for example, vinegar, citric acid, as well as table salt, sugar and artificial sweet substances such as saccharin, dulcin). The aforementioned taste substances are added to food either during its consumption or during its preparation. Some taste substances are formed in food products themselves during their preparation, for example, during baking or frying, or are obtained from food products through special treatments used, for example, in the manufacture of meat extract, meat broth. Certain rather nutritious food products and even dishes are also classified as taste substances, when their consumption is aimed not so much at the nutritional elements they contain as, primarily, at their taste characteristics; such taste substances include certain so-called appetizers, fruits, vegetables. Substances that are consumed not only because of their taste characteristics but also because of their special effect on the central nervous system are also considered as taste substances; this group of taste substances includes tea, coffee, cocoa. Tobacco can also be classified to a certain extent as a taste substance. - Drawing a precise boundary between taste and food substances is not always possible, since taste substances may contain certain amounts of nutritional elements; sugar can be considered both as a taste and as a food substance; depending on special living conditions, taste substances may take the place of food substances, and vice versa; for example, in Germany during the imperialist war, many used meat only as a taste substance. Taste substances should have a direct effect on the taste and olfactory nerves, not always a direct effect on the activity of the stomach and intestines, but a reflex effect on the brain, heart and other organs. Taste substances as such do not increase the digestive ability of gastric juice; M. Popov's experiment showed that adding taste substances to artificial gastric juice either has no effect on the peptonization of proteins, or slows it down, or even completely stops it. When adding taste substances to hard-to-digest food, Bischof and Hoffmann did not observe any improvement in its digestibility. Experiments feeding animals tasteless food showed that such food was digested satisfactorily, but prolonged feeding with it was difficult, as animals stopped consuming it. The irritation of the taste nerves and the olfactory organ caused by taste substances reflexively causes abundant saliva secretion, which automatically affects the work of the pancreas and bile secretion. Pavlov's experiments with dogs showed that only substances that stimulated the dogs' appetite could reflexively cause gastric juice secretion. Brandl, who conducted experiments on a dog to which aqueous solutions of peptone and sugar were introduced into the stomach through a permanent fistula, with the exit of the stomach closed by a rubber balloon, noticed that significantly larger amounts of the substances introduced into the stomach were absorbed in the case when mustard oil, pepper, alcohol, table salt were added to them. Gottlieb's experiments with rabbits indicated a significant increase in pancreatic juice secretion when the stomach was locally irritated by mustard, pepper, acids; pancreatic juice secretion was particularly great when the mucous membrane of the duodenum was simultaneously irritated. The physiological action of spices consists in the fact that they mainly have a reflex effect on the digestive organs, stimulating appetite, while other spices can also directly have some juice-secreting effect, which is particularly noticeably expressed in the secretion of saliva and pancreatic juice; the motor and absorbing capacity of the digestive canal under the influence of spices also increases, and the digestive leukocytosis increases (under the influence of essential oils), which to a certain extent facilitates the absorption of nitrogenous food substances. References in the literature indicating that essential oils have a disinfecting effect and therefore can influence the processes of decomposition of the food pulp and its absorption should be accepted conditionally, since this property is insignificant and manifests itself only with relatively large amounts of essential oils. - As for bitter substances, they are generally close to spices in terms of their effect on the digestive organs; experiments with dogs indicate that bitters reflexively enhance secretion and absorption in the intestines; this increase is relatively more persistent than with spices, the effect of which occurs quickly and quickly ceases. - Meat extracts and broths, fish soup, mushroom soups and soups do not have the nutritional value that was attributed to them in former times; the extractive substances contained in them cause the secretion of large amounts of gastric juice by directly irritating the walls of the stomach. For sick people, broth and fish soup serve to a certain extent as dietary and therapeutic means, while soluble phosphates can have a temporary stimulating effect on the muscular system. - Taste substances containing alkaloids, by having a stimulating effect on the central nervous system, have the ability to eliminate or alleviate the feeling of fatigue and enable the body, tired from mental or physical work, to perform some work. From a sanitary point of view, their consumption can be tolerated only where, depending on certain exceptional conditions, it is necessary to preserve the ability to work for a certain period of time, as is the case, for example, with mental fatigue, difficult military marches, mountain ascents, etc.; stimulating agents can also have important significance in weakening of heart activity during infectious diseases, when it is necessary to maintain heart activity for a certain period of time (crises). Taste substances containing stimulating agents are used not only in the cases mentioned, but represent items of daily consumption. Under the influence of the alkaloids contained in coffee, tea (caffeine) and cocoa (theobromine), excitation of the central nervous system occurs; perception of impressions and mental activity are facilitated, the feeling of fatigue and drowsiness, sluggishness of thinking decrease or disappear, the desire for work increases. Excessive consumption of tea or coffee leads to increased excitability, palpitations, arrhythmia of cardiac activity, insomnia. Excessive consumption of alcoholic beverages leads to the sad consequences of alcoholism. When choosing taste substances, the taste preferences of consumers should be taken into account; the same substance, for example, onion or garlic, may be acceptable as a taste substance for some, while for others it may cause a feeling of aversion. In addition, it must be borne in mind that with prolonged consumption of many taste substances, they cease to act as such; therefore, when using taste substances, there should be periodic change and a certain variety. A certain norm regarding the amount of taste substances should also be observed, since their consumption in large quantities can lead to very severe pathological phenomena, as is observed, for example, with prolonged abuse of tea, coffee, alcoholic beverages, tobacco. - In addition to the use of taste substances, appetite stimulation, secretion of digestive juices and in general improvement of digestion can also be caused by other means: these include the appropriate ('appetizing') appearance of food, the appearance of the dishes in which food is served, as well as the appropriate, favorable for food consumption, conditions of the dining rooms (convenient, light, well-ventilated rooms).