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Substantiation of the expedience of using of natural antioxidants for inhibiting of oxidative and hydrolytic rancidity in confectionary industry is an urgent direction. The offered way of solving the problem is to use a fat-less grape seed powder, a product, obtained as wastes of vine-making as a source of antioxidants. For this aim, there were realized experimental studies of water-alcohol extracts (ethanol, isopropanol) by the method of gas chromatography with mass-spectroscopic detection (CG-MS) of the chemical composition of grape seed powders under industrial conditions. The obtained data allowed to establish that the studied extracts contain an essential amount of phenol compounds of the different origin: aromatic acids – gallic and egallic acids; resveratrol; flavonoids – quercetin and its derivatives, catechine, epicatechine, campferol and others alongside with esters of fatty acids. These components are strong antioxidants, and their introduction to a grape seed powder must favor inhibition of the oxidizing process of fats in fat-containing confectionary products, so increasing shelf-life of products.

The polyphenol composition of grape seeds powder (GSP) and defatted grape seeds flour (DGSF) in water­alcohol (ethanol, isopropanol) extracts was studied by the chromatographic method. There was established the content of antioxidants, which are present in the form of phenolic acids (gallic, ellagic), stilbenes (resveratrol) and flavonoids, first of all, flavanols (catechin, epicatechin) and flavonols (kaemferol, myricetin, quercetin and its derivative glycosides). It was shown that the total content of polyphenols reaches a maximum size of about 4.5 % in gallic equivalent of the powder weight at the extraction of water­ethanol mixture with ethanol content of 50 % (w/w). The effect of phenolic antioxidants on peroxide (PV) and acid (AV) values of confectionery fats of lauric and non­lauric types in the model systems was studied as the markers of the rancidity formation process. It was proved that thanks to a high content of antioxidants in grape powders, the introduction of these powders in the composition of samples significantly slows down the process of auto­oxidation of fats. It was shown that grape powders as vegetable raw material are more stable in terms of catalyzing the process of fats hydrolysis in confectionery glaze. This is evidenced by the data on the activity of lipase enzyme, the magnitude of which is lower in the samples of grape seeds powders – 1.03 and 1.12 nm 3 /g for GSP and DGSF, respectively, compared with that of different samples of cocoa powder – 0.84 and 1.87 nm 3 /g. The study into changes in acid value of the samples also showed that the addition of GSP and DGSF as the source of antioxidants significantly inhibits the process of hydrolysis of fats to free fatty acids. The obtained results have a practical significance for the improvement of the process of confectionary glaze production in the direction of partial substitution of cocoa powder with grape seeds powders. This contributes to the creation of a product with a high nutritional value and which is more resistant to damage as a result of the process of oxidation and hydrolysis of fats

The article considers the safety and environmental cleanliness of grapeseed powders compared to the natural and alkalized cocoa powders. The content of heavy metals in the investigated powders has been determined by the atomic adsorption method; radionuclide activity has been determined by the spectrometric method; the presence of mycotoxins B1, T-2-toxin, zearalenone, and deoxynivalenol (vomitoxin) has been determined by thin-layer chromatography; the amount of nitrates has been determined by the ionometric method; contamination of powders with organophosphorous and organochlorine pesticides has been determined by chromatographic method. According to the results of experiments, the content of heavy metals in all investigated powders is within the limits of the maximum permissible concentration, whilst powders of grapeseeds are notable for a significantly lower mass content of plumbum, zinc, copper salts. As for the radioactivity of grapeseed powders, the activity of radionuclides is significantly below the permissible level. Presence of aflatoxin В1 has been detected in the alkalized cocoa powder sample, of zearalenone – in the grapeseed powder oilcake sample. Their concentration does not exceed the allowable concentration. Mycotoxines are absent in other samples investigated. Concentration of nitrates in the natural and alkalized cocoa powder samples is by 20–30 times higher than that found in grapeseed powders. The content of organophosphorous and organochlorine pesticides in all cocoa powder samples and all grapeseed containing powders is below the method’s threshold of detectability. The glaze samples containing the additives investigated have a considerably lower content of heavy metals compared to the reference samples. Glaze with cocoa powder partially replaced with grapeseed powders has high organoleptic quality parameters. During the glazing process, it is applied on the surface of products in thin layers and cools down in small waves. The results obtained prove that domestic raw materials are safe for human health, and confectionery glaze containing grapeseed powders as partial replacement of the cocoa powder has high safety characteristics.