Biochemistry

in the large intestine under the influence of anaerobic microbes, causing severe pain and impaired intestinal function. Some fatty acids found in meat of various species of fish can have a toxic effect. The group of biologically active food substances also includes social toxicants - ethanol, caffeine, theobromine, theophylline, biogenic amines. Ethanol cannot be considered only as a biologically active substance, because it is a source of energy. However, its drug effect is disproportionately more pronounced than energetic effect; therefore this substance is considered as an agent that poses a health hazard. Stimulants of nervous activity ’ (caffeine, theobromine, theophylline) are components of tea and coffee, and biogenic amines (tyramine, DOPA, norepinephrine, serotonin) found in many animal products (cheeses, liver, salted fish) and plant origin (tomatoes, oranges, bananas, pineapples), can come in concentrations sufficient for the manifestation of pharmacological activity, for example, in hypertension. The components that have an adverse effect on the human body also include antialimentary substances that reduce the digestibility of certain substances, in particular, proteinase inhibitors, anti-vitamins and demineralizing factors. The composition of food products includes substances that destroy vitamins or interfere with their absorption. So, in raw cabbage, lettuce, celery, parsley leaves, horseradish, carrots, cucumbers, pea seedlings, there are enzymes that oxidize vitamin C. In the raw egg yolk there is a fraction - avidin, which match one of the В vitamins (biotin) into an indigestible compound. An enzyme that destroys vitamin B t has been found in raw fish. Coffee contains a substance that interferes with the absorption of vitamin Bp Some products have toxic substances. So, green potatoes and their sprouts contain the toxic substance solanin, which is partially destroyed by heat treatment. The cause of many accident of food poisoning is the toxic components of food. For example, there are plants that produce cyanogenic glycosides, which, under appropriate conditions, turn into hydrogen cyanide - the most powerful cytochrome oxidase inhibitor. Amygdalin glycoside is formed in almonds, cherries, apples, pears, plums. In a number of countries in the Mediterranean, a disease is quite common, characterized by the development of jaundice, an increase in the liver and spleen. It has been proved that this disease is associated with the consumption of horse beans producing glucosides - vicin and convicin, which are hydrolyzed in the gastrointestinal tract to the corresponding aglycones. Poisoning substances are found in special varieties of peas grown in India, also honey from heather flowers may be toxic. 298