This paper considers ways of using walnut shells for food products. The study is based on three varieties of walnut as raw materials. Such physicochemical indicators as the shape, mass, thickness, kernel yield, fat, protein, ash, vitamins, minerals, amino acids, and bioflavonoids have been investigated. The results showed that the walnut shell has a large, rounded, and round-ovoid shape. The weight of the shell ranges from 11.7 to 14.1 g, the thickness ‒ from 1.5 to 1.6 mm, the kernel yield ‒ from 45.7 to 48.8 %. The fat content ranges from 0.7 to 0.9 %, the protein content ‒ 2.4 to 2.5 %, the ash content ‒ from 1.6 to 1.7 %. The study of vitamins in the walnut shell showed that vitamin A is absent in the shell of all varieties of walnut. The content of the vitamin E ranges from 8.59 mg to 9.53 mg, the content of the vitamin C ‒ from 9.31 mg to 15.0 mg, and the content of β, carotene, ‒ from 0.053 to 0.070 mg. The studies have also shown a fairly rich amino acid composition of walnut shells. The results demonstrated that the shell of walnut contains a sufficient amount of daily intake of vitamins. The results of investigating mineral substances showed that the iodine content ranges from 5.52 μg to 14.81 μg, iron ‒ from 3.33 mg to 7.39 mg, and zinc ‒ from 3.1 mg to 6.9 mg. The content of quercetin in the shell of a walnut ranges from 0.945 mg to 1.51 mg, catechin ‒ from 2.46 mg to 12.07 mg, tannins ‒ from 611.32 mg to 805.62 mg. Based on the results of the analysis, it is planned in the future to devise technology for obtaining an extract that could be used as a food additive in a soft drink, enriching it with the missing nutritional components.

Phenolic compounds extracted from walnut shells are potentially good natural sources of antioxidants for the food industry and have numerous health benefits. Walnuts have more antioxidant capacity than any other nut because the shell is primarily composed of lignin, a strong source of phenols. Studies demonstrated that lignin characterizes the shell strength level and is a source of antioxidants due to its chemical composition. In the current study, an extract obtained by extraction with a hydroalcoholic solvent of various concentrations from a walnut shell was investigated. The results of this study have proven that walnut shell extract contains the main sources of mineral elements and vitamins, which are of great importance. According to the biological value, this extract contains essential amino acids for the body. The high content of quercetin and catechin shows the antioxidant activity of the extract. In the present article, the authors disclose methods for obtaining an experimental batch of a prophylactic product based on walnut shells and give the product a technological characteristic. Consequently, a product was developed for prophylactic usage of 10 ml per 100 ml of water and must be taken 1-2 times a day for 21 days. The required product amount was calculated from the daily intake of vitamins, minerals, and flavonoids.