I. B. Medvedeva

Formation of flavor of dry champignons (Agaricus bisporus L.)

The composition of aroma compounds of dry champignons (Agaricus bisporus L.) were identified using capillary gas chromatography and chromatography-mass spectrometry. In total, 56 compounds were identified. It was found that the flavor of dry mushrooms was formed by the volatile compounds produced as a result of enzymatic and oxidative conversion of unsaturated fatty acids as well as in the Maillard reaction. Unsaturated alcohols and ketones containing eight carbon atoms determined the mushroom note of the product. The specific aroma of dry mushrooms was determined by a complex composition of substituted sul- fur-, oxygen-, and nitrogen-containing heterocyclic compounds as well as by aliphatic carbonyl compounds and methional. It was found that the concentrations of volatile carbonylic and heterocyclic compounds increased after the addition of a mixture of amino acids to mushrooms before drying. As a result, the intensity of the aroma of dry mushrooms increased.

Effect of oregano essential oil on the engraftment and development of Lewis carcinoma in F1 DBA C57 black hybrid mice

The effect of a low uptake dose of oregano essential oil with drinking water for three months (Origanum vulgare L.) on the degree of Lewis carcinoma engraftment and some parameters of oxidative stress has been studied in vivo using F1 DBA C57 Black hybrid mice. Oregano essential oil has been established to possess an anticancer activity. The degree of tumor engraftment decreased by 1.8 times, its size decreased by 1.5 times, and the development of tumor was significantly suppressed in sick mice under the effect of oregano essential oil. It was found that the uptake of essential oil did not affect the intensity of lipid peroxidation in the brain of mice and resulted in a significantly (by 36%) decreased content of secondary lipid oxidation products in the liver as shown in a reaction with thiobarbituric acid as compared to control subjects. The activity of antioxidant enzymes was found to increase after three months of essential oil uptake (by 1.5–3 times) as compared to the control group. This effect of essential oil supports the presence of bioantioxidant properties in this essential oil.

[Autooxidation of a mixture of lemon essential oils, methyl linolenoate, and methyl oleinate].

Stability of components of a mixture of methyl linolenoate and methyl oleinate with two lemon (Citrus limon L.) essential oils in hexane during their autooxidation in light was studied by gas chromatography. The essential oils differed by their quantitative ratio of components: the single-fold (1x) oil contained approximately 90% monoterpene hydrocarbons and 1.47% citral, whereas the proportions of hydrocarbons and citral in the tenfold (10x) oil were approximately 60 and 18.32%, respectively. The concentration and composition of essential oils influence the rates of fatty-acid oxidation and fatty-acid peroxide cleavage. The 1x lemon oil inhibited the oxidation of methyl linolenoate and methyl oleinate, whereas the 10x oil accelerated these processes. The distinctions in the resistance of the major components of lemon essential oil to oxidation, which are determined by their composition and antioxidant properties of unsaturated fatty acids, were revealed.

The composition of volatile components of dry cepe and oyster mushroom

The composition of aroma compounds in dry cepe mushroom (Boletis edulis Fr.) and oyster mushroom (Pleurotus ostreatus Fr.) was studied using capillary gas chromatography and chromatography—mass spectrometry. In dry cepe, 53 volatile compounds were identified, and in dry oyster mushroom 41 compounds were identified. Volatile organic substances with various functional groups formed the flavor of dry mushrooms. Unsaturated alcohols and ketones with eight carbon atoms were responsible for the mushroom notes of products. Their content in dry cepe was much higher than in dry oyster mushroom. The specific aroma of dry cepe was formed by the complex mixture of methional, substituted furans, pyrazines, and pyrroles. The content of these compounds was higher in dry cepe than in dry oyster mushroom. The content of aromatic and aliphatic aldehydes with six, nine, and ten carbon atoms was higher in dry oyster mushroom. The differences in the qualitative and quantitative composition of volatile compounds are responsible for more intensive and pleasant aroma of dry cepe in comparison to that of dry oyster mushroom.

Antiradical properties of essential oils and extracts from clove bud and pimento

The antiradical properties of essential oils and extracts from the clove bud (Eugenia caryophyllata Thumb.) and berries of tree (Pimenta dioica (L.) Meriff.) were studied and compared with the properties of synthetic antioxidant ionol (2,6-ditret-butyl-4-hydroxytoluene, BHT) in model reactions with the stable free 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. The essential oils of clove bud and pimento had qualitatively close composition of the main components but differed by their quantitative content. In the studied samples, eugenol was the main compound with high antiradical activity. The reaction rates of essential oils and extracts with the DPPH radical were practically the same for essential oils and twice the reaction rate of BHT. The values of antiradical efficiency (AE) were also close for essential oils and were twice that for extracts and ionol. A synergetic action of components in the essential oil and extract of pimento on antiradical efficiency values was found.

[Effects of low doses of essential oil on the antioxidant state of the erythrocytes, liver, and the brains of mice].

We studied the effects of essential oils from oregano and clove and a mixture of lemon essential oil and a ginger extract on the antioxidant state of organs in intact and three experimental groups of Balb/c mice. We found that in vivo essential oils were efficient bioantioxidants when mice were treated with it for 6 months even at very low doses, such as 300 ng/day. All studied essential oils inhibited lipid peroxidation (LPO) in the membranes of erythrocytes that resulted in increasing membrane resistance to spontaneous hemolysis, decreasing membrane microviscosity, maintenance of their integrity, and functional activity. The essential oil significantly decreased the LPO intensity in the liver and the brain of mice and increased the resistance of liver and brain lipids to oxidation and the activity of antioxidant enzymes in the liver. The most expressed bioantioxidant effect on erythrocytes was observed after clove oil treatment, whereas on the liver and brain, after treatment with a mixture of lemon essential oil and a ginger extract.

Inhibition of linseed oil autooxidation by essential oils and extracts from spice plants

Clove bud essential oil, extracts from ginger, pimento and black pepper, or ascorbyl palmytate were studied as natural antioxidants for the inhibition of autooxidation of polyunsaturated fatty acids in linseed oil. Different methods were used to estimate antioxidant efficiency. These methods are based on the following parameters: peroxide values; peroxide concentration; content of degradation products of unsaturated fatty acid peroxides, which acted with thiobarbituric acid; diene conjugate content; the content of volatile compounds that formed as products of unsaturated fatty acid peroxide degradation; and the composition of methyl esters of fatty acids in samples of oxidized linseed oil.

Influence of the composition of essential oils on their antioxidant and antiradical properties

The antiradical and antioxidant properties of essential oil mixtures (EOMs) with various compositions in model systems of hexanal autooxidation, thermal oxidation of methyl linoleate and β-carotene, and in a reaction with the stable diphenylpicrylhydrazyl radical were studied and compared. It was found that all studied EOMs exhibited antiradical activity. The highest antiradical activity was observed for an EOM containing monoterpene hydrocarbons as the main components (the phenol content was low). The antioxidant activity of all EOMs was from 60 to 98% and depended on the model system composition and the method of assay. The mixture with the maximum phenol content exhibits the highest antioxidant activity level in the hexanal autooxidation system. EOMs with a high content of phenols and α- and γ-terpinenes were the most efficient antioxidants in the β-carotene model system. The study confirmed the possibility to vary the antioxidant and antiradical properties of essential oils by preparing their mixtures with a specific composition.

Binding of Volatile Organic Compounds to Food Biopolymers

Capillary gas chromatography was used to study the influence of the composition and structure of different food polymers (polysaccharides, vegetable fibers, and animal protein gelatin) on the binding of essential oil components. The retention of volatile organic compounds on biopolymers was shown to depend on their molecule structure and the presence, type, and position of a functional group. The maximum extent of the binding was observed for nonpolar terpene and sesquiterpene hydrocarbons, and the minimum extent was observed for alcohols. The components of essential oils were adsorbed due mostly to hydrophobic interactions. It was shown that the composition and structure of a compound, its physico-chemical state, and the presence of functional groups influence the binding. Gum arabic and guar gum were found to bind nonpolar compounds to a maximum and minimum extent, respectively. It was demonstrated the minimum adsorption ability of locust bean gum with respect to all studied compounds.

Binding of Aliphatic Aldehydes by Cornstarch Polysaccharides

Binding by cryotextured cornstarch of individual aliphatic aldehydes (C6–C10; saturated or unsaturated) and their mixtures from aqueous solutions has been studied using capillary gas chromatography. The amount of compounds sorbed by the cryotextures depended linearly on the concentration of aldehydes in the original gel. The majority of the compounds under study were bound irreversibly. Aldehydes with low molecular weight were better sorbed by the cryotextures than by granules of native cornstarch. Data of IR spectroscopy demonstrated that binding to cornstarch polysaccharides decreased the conformational mobility of odorants. The appearance of binding isotherms depended on the extent of sorption, suggesting the involvement of complex mechanisms of binding. The formation of supramolecular complexes through cooperative hydrophobic interactions between aldehydes and cornstarch polysaccharides was the preferential mechanism of the sorption.