PHYSICO-CHEMICAL DETERMINATION OF CARBOHYDRATES IN THE FOODS AND BEVERAGES
Vestnik Voronežskogo Gosudarstvennogo Universiteta Inženernyh Tehnologij
Summary. The extraction of fructose, glucose, galactose, sucrose and lactose from aqueous salt solutions, hydrophilic solvents (aliphatic alcohols, alkyl acetates, ketones) of double and triple mixtures has been studied. Under identical conditions set quantitative characteristics extraction has been established. It was found that from the all studied carbohydrateы most fully extracted disaccharides lactose and sucrose. The conditions of concentration and almost complete recovery of
... ery of carbohydrates from aqueous salt solutions has beenoptimized. The technique of extraction-potentiometric selective determination of carbohydrates in foods and beverages has been developed. As a titrant was used isopropanol solution of boric acid. The developed method allows to determine separately the mono- or disaccharides in milk, which include those contained 5 or less carbohydrates. The complex of photocolorimetric, polarimetric, potentiometric and chromatographic methods for determining carbohydrates in aqueous media and food (diabetic confectionery, juices, dairy products, honey) wasproposed. To determine the fructose, glucose and sucrose in natural juices us used optical methods (photoelectrocolorimeters, polarimetry). Method is express, does not require expensive equipment and reagents. Fructose and sucrose in diabetic confectionery was determined by ascending thin layer chromatography. Some diabetic products based on fructose, produced by Russian confectionery factorieshas beenanalyzed. Duration analysis, 50-60 minutes, selective determination of error within 5-7%. Extracts from honey and milk were analyzed potentiometrically. We have developed a technique characterized by the following advantages compared with state standards: rapidity (analysis time 30-35 min), accuracy (relative error within 5 %), does not require expensive equipment and reagents, as well as dilution and filtration of milk stage sampling.