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In our country, a limited number of chemicals are used for canning. Their use is allowed only in cases where other methods of conservation are ineffective.
Three groups of chemicals are allowed for use: antiseptics, antibiotics, antioxidants.
Preservation with antiseptics. At present, benzoic, sulfuric, boric, sorbic acids and their compounds are used for canning products in industrial conditions.
There are a number of requirements for antiseptics, they should not:
have a toxic effect on the human body in authorized doses; inhibit the action of enzymes of the gastrointestinal tract;
destroy vitamins contained in foods; change the organoleptic and physico-chemical properties of products;
accumulate (cumulate) in the human body.
For each of the used antiseptics, a laboratory methodology for determining them in food should be developed.
Benzoic acid is used (at the rate of 70-100 mg / kg of product) in the production of melange, fruit and berry semi-finished products, in the manufacture of marmalade and marmalade, fruit juices, caviar, canned fish. Benzoic acid does not have pronounced antiseptic properties, its effect is manifested only in an acidic environment. The natural content of benzoic acid in lingonberries and cranberries (500-2000 mg / kg) ensures their long-term preservation.
Sulfuric acid is used to preserve vegetables, fruits, berries, a process called sulfitation. In the industrial preparation of products, sulfuric acid compounds are used - sodium pyrosulfite, sulfur dioxide, sulfur dioxide and sodium bisulfite. In public catering enterprises, sodium bisulfite is used to sulfate potatoes. Sulfuric acid and its compounds destroy vitamin Bi (thiamine), therefore, it is not used for preserving products containing thiamine. Significant destruction (up to 70%) of sulfuric acid preparations occurs during the heat treatment of products. Due to changes in the organoleptic properties of meat, fish, egg and dairy products, their conservation with the help of sulfuric acid and its compounds is not allowed.
Sorbic acid is used in the food industry relatively recently. Its negative effect on the human body and the properties of the products are not marked. Sorbic acid is used in a concentration of 0.1% for the preservation of juices, berries, apples, granular caviar, in the preparation of mayonnaise, soft drinks, cheeses.
Boric acid and sodium borate (borax) are used for conservation purposes in a limited way, since they cause impaired renal and intestinal function and have the ability to accumulate in the body.
Boric acid is currently approved for the production of salmon caviar and melange.
Preservation with antibiotics. In order to maintain the quality of certain food products (meat, fish, poultry), to inhibit the growth of microorganisms, antibiotics are used. The following requirements are imposed on antibiotics: they must not change the organoleptic properties of the products, be stable in the environment and during the heat treatment of products.
Antibiotics are of limited use, as they can cause the variability of microbes and the appearance of antibiotic-resistant forms.
To preserve the quality of meat in carcasses of carcasses and fish during their transportation, biomycin ice is used (5 g of the preparation per 1 ton of ice), with which meat and fish are transferred, and the residual content of biomycin in the raw product is normalized to not more than 0.25 mg / kg. After heat treatment, the antibiotic content in the product is not allowed.
To prevent the development of mold and yeast during transportation and storage of meat carcasses, the use of a combined solution of biomycin is allowed
and nystatin. The solution is applied by irrigating the surface of the carcasses. The concentration of the solution is strictly standardized.
For the preservation of vegetables (green peas, tomatoes, cauliflower, etc.), in the production of cheeses, canned milk, nisin is used. Nisin inhibits the growth of staphylococci, streptococci, spore-forming bacteria. Staphylococci and Cl are especially sensitive to nisin. perfringens. Mildew and yeast are resistant to lowlands. By acting on spores of heat-resistant bacteria, nisin weakens their resistance to heat. This allows you to reduce the sterilization temperature of canned food, thereby preserving the biological value of the products to a greater extent.
Once in the human body, nisin is rapidly destroyed in the digestive tract, without adversely affecting the beneficial intestinal microflora.
The use of antioxidants. Antioxidants are chemical compounds that prevent the oxidation of fats, i.e., prevent their deterioration.
To maintain the quality of fats during storage, it is necessary to create favorable conditions - to exclude the effects of light, heat, oxygen, moisture. The spoilage of fats intended for storage for more than three months is also hindered by the use of antioxidants.
One of the antioxidants is ascorbic acid and its salts, which, in addition, increase the nutritional value of fats in vitamin terms.
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