Кластеризація води в дегідратованній зооглеї “tibetan milk mushroom”

• Date: 2019
• Main Authors: Крупська, Т. В., Скубішевська-Зіеба, Я., Хармас, Б., Цапко, М. Д., Туров, В. В.
• Format: Article
• Language: Russian
• Published: Chuiko Institute of Surface Chemistry National Academy of Sciences of Ukraine 2019
• Subjects: молочний гриб; поліасоціати води; 1Н ЯМР – спектроскопія; ДСК – термограмми
• Online Access: https://surfacezbir.com.ua/index.php/surface/article/view/692
• Journal Title: Surface

By the methods of DSC, NMR spectroscopy and thermal analysis, the state of water in partially dehydrated cell cultures of the Tibetan milk fungus was studied. It was found that when the water content in the samples is up to 0.8 g/g, all water is associated with cellular structures. Water is predominantly in a highly associated state, when there are 2-3 hydrogen bonds per molecule. In air at CH2O = 0.3 g/g, most of the water is part of clusters with a radius of R = 10 nm. With an increase in water concentration to 0.8 g/g, three maxima are present on the distribution curves at R = 1, 2, and 12 nm. The same maxima are also present when air is replaced by a chloroform medium. It is possible to differentiate the structure of various water clusters in the cellular systems of a Tibetan milk fungus using chloroform medium with the addition of trifluoroacetic acid. In this case, in the 1H NMR spectra there are four water signals related to clusters having different dissolving powers with respect to acid. About half of the bound water is part of acid-insoluble clusters. Two endothermic peaks are recorded on thermograms of thawing of a pure dean. One at T = -28 °C, which coincides with the passport melting point of the dea, and the second at T = -8 °C. Probably, part of the decane is able to maintain crystallinity at a temperature significantly higher than the melting temperature of the bulk of the substance. On the DSC curves of thawing of a sample of milk fungus biomaterial containing equal amounts of adsorbed water and decane, several endothermic maxima are observed. Considering that at the chosen concentration, the peak of water defrosting is not observed, the most intense peaks (T = -28 and T = -25 °C) should be attributed to the process of dean melting. Peaks of lower intensity can also be associated with the melting of various forms of crystalline decane stabilized by the surface of the biomaterial