Research on the chemical composition of fruit and berry raw materials in the North Caucasus region as a promising source of food and biologically active substances

The purpose of research is to study the chemical composition of semi-finished products from wild fruit and berry raw materials of Republic of North Ossetia - Alania of North Caucasus Region, obtained by quick freezing. We used sea buckthorn fruits, viburnum berries and blackberries, samples of which (during their technical ripeness) were taken on the territory of the Alagir municipality in the village of V. Fiagdon, Republic of North Ossetia - Alania. Average samples were taken from the samples, which, after preparation, were crushed and rubbed through a sieve with a cell diameter of 1.5 mm to obtain a puree. 10.0 % sucrose (to the mass of the puree) was added to the experimental puree samples as a cryoprotectant. The content of pectin substances was determined according to GOST 29059-91. Pre-isolated and prepared pectin substances were titrated with alkali before and after hydrolysis. The amount of protopectin was determined by the difference between the total content of pectin substances and the content of water-soluble pectin. The content of anthocyanins was determined according to GOST 32709-2014 by the spectrophotometric method. To determine the vitamin C content, the titrimetric method set out in GOST 24556-89 was used. The sugar content was determined according to GOST 8756.13-87 using the permanganate method. The amount of organic acids was determined by the titrimetric method according to GOST 6687.4-86. The content of polyphenolic substances was determined by the photocalorimetric method. Content of macro- and microelements were determined by atomic absorption method. The study was carried out in triplicate, statistical processing of experimental data was carried out using Excel and Statistica 7.0 programs. The developed technology for quick-frozen fruit and berry semi-finished products does not significantly reduce their nutritional value compared to fresh raw materials, and the organoleptic characteris- tics only slightly deteriorate after long-term storage. The content of ascorbic acid, polyphenolic substances, organic acids, carbohydrates (including pectin substances), and mineral substances is maintained at the level of 75-90 %. The high content of macro- and microelements in quick-frozen semi-finished products from fruits and berries makes it possible to satisfy the daily requirement for them by 6.0-13.0 %.