Stolecka-Warzecha A
Medical University of Silesia, Poland
Title: The quality changes in different food fatty acids during storage assessed with the NMR technique
Biography
Biography: Stolecka-Warzecha A
Abstract
The aim of the work was to verify the hypothesis that external factors such as elevated temperature and UV irradiation can change the chemical structure of fatty acids and how these possible changes aff ect their molecular dynamics. Cocoa butter and cocoa paste as rich sources of fatty acids have been studied. Cocoa butter and cocoa paste contains saturated and unsaturated acids mixture (palmitic acid, stearic acid, oleic acid, linoleic acid). Th e samples were exposed to elevated temperatures of 40°C and the infl uence of UV irradiation with the dose of 300W/m2 for 1000h. Th e analysis of the chemical structure of fatty acids was carried out using an NMR spectrometer. NMR spectra were recorded at room temperature using a Bruker Ascend 600 spectrometer (Bruker, Billerica, MS, USA). Molecular dynamics were analyzed using NMR relaxometry. NMR relaxometry is a unique experimental method probing mechanisms and characteristic time constants of dynamical processes in condensed matter on the atomistic level. In contrary to NMR spectroscopy which it is focused on molecular structure, NMR relaxometry probes molecular dynamics. Th is summarizes the concept of the research: as it has turned out those structure-oriented methods may be not suffi cient for discriminating between fatty acids storage at the diff erent conditions (temperature, UV irradiation). Furthermore, the next try is to attempt to reveal characteristic dynamical features of these materials. Standard NMR relaxation experiments are performed at a single frequency to determine the structure of the matter. Here, the experiments are carried out in a wide frequency range from about 5kHz to 40MHz (for 1H). By NMR relaxometry, it is possible to detect motional processes across a huge range of time scales (from MS tons) by single experiment. Obtained results indicate the importance of storage conditions for products rich in fatty acids. Even small changes of chemical structure of the fatty acids can infl uence on their molecular dynamic.