Projects / Programmes
Biokemijska in biofizikalno-kemijska karakterizacija naravnih snovi (Slovene)
| Code |
Science |
Field |
Subfield |
| 4.03.07 |
Biotechnical sciences |
Plant production |
Technology of vegetal origin food |
| Code |
Science |
Field |
| T430 |
Technological sciences |
Food and drink technology |
| P400 |
Natural sciences and mathematics |
Physical chemistry |
naturally occuring substances, coligative properties, transport and volumetric properties, electrolytic conductivity, HPLC, enzymatic hydrolysis, spectroscopy
Researchers (12)
Abstract
In the report the viscosities and apparent specific volumes of pectic acid and its’ lithium salt in aqueous solutions as well as some other solutes, e.g. poly(ethylene glycol)s, 1-octanol, 1-nonanol, 1-decanol and cyclohexanol in aqueous and nonaqueous media are given. The partial molar or partial specific volume of the solute and solvent and molar or specific excess volume of the solution were evaluated and interpreted in terms of solute-solute and solute-solvent interactions. The limiting partial molar volume of the solute was interpreted in terms of the scaled particle theory. The ''''solvent effect'''' on the partial molar volume of the solute was found to be due mainly to cavity formation and intermolecular dipersion forces. The intrinsic viscosity and the viscosity average molecular weight of the solute was calculated applying Eyring’s transition state theory. The thermodynamic functions of activation of viscous flow of binary mixtures i.e. the molar Gibbs free energy, entropy and enthalpy were estimated and interpreted in term of the relative effects of solute on the ground and transition state solvent.
In addition, the optimal conditions of corn starch liquefaction and dextrinization using alpha-amylase from Bacillus subtilis to obtain maltodextrins with a dextrose equivalent of 12,9 - 23,5 were obtained. The pattern of action of B. subtilis alpha-amylase on native corn starch was monitored using high-pressure liquid cromatography (HPLC) and high-performance thin layer chromatography (HPTLC). It was possible to separate malto-oligosaccharides of up to 9 glucose units by HPLC and those of up to 12 glucose units by HPTLC, respectlively. The polyphenols from fresh leaves of Sempervivum tectorum were isolated using an extraction technique. After acidic hydrolysis of the oligomeric polyphenols, it was established by TLC, HPLC and FAB mass spectra that kaempferol was the unique aglycon of the three main oligomeric constituents of S.tectorum.
