Radosław Kowalski

Raman studies of gluten proteins aggregation induced by dietary fibres.

Interactions between gluten proteins and dietary fibre preparations are crucial in the baking industry. The addition of dietary fibre to bread causes significant reduction in its quality which is influenced by changes in the structure of gluten proteins. Fourier transform Raman spectroscopy was applied to determine changes in the structure of gluten proteins modified by seven dietary fibres. The commercially available gluten proteins without starch were mixed with the fibres in three concentrations: 3%, 6% and 9%. The obtained results showed that all fibres, regardless of their origin, caused the same kind of changes i.e. decrease in the α-helix content with a simultaneous increase in the content of antiparallel-β-sheet. The results indicated that presence of cellulose was the probable cause of these changes, and lead to aggregation or abnormal folding of the gluten proteins. Other changes observed in the gluten structure concerning β-structures, conformation of disulphide bridges, and aromatic amino acid environment, depended on the fibres chemical composition.

The Content and Composition of Essential Oil of Origanum majorana L. Grown in Poland Depending on Harvest Tme and Method of Raw Material Preparation

Abstract: Volatile components of marjoram (Origanum majorana L.) essential oil obtained from the air-dried ground and unground herb, collected at full flowering (1st harvest), and from regrowth stems (2nd harvest) was analysed by GC-MS and GC-FID. The studied plants belong to the trans-sabinene hydrate chemotype, and the average percentage of this compound was 49.12 %. The harvest of the herb at full flowering stage (July) allows to obtain an oil containing more cis-sabinene hydrate, sabinene as well as cis- and trans- sabinene hydrate acetates than that obtained from the second harvest in October, from which we obtain, in turn, more trans-sabinene hydrate, linalyl acetate, and E-caryophyllene in the oil. These modifications may be important for the practical application of marjoram essential oil and herbal raw material itself. The grinding of marjoram raw material should be considered to be a treatment that enhances the fragrance of the spice. The separation of low-value stems allows obtaining an oil with a higher proportion of sabinene and cis-sabinene hydrate.

Essential Oil Composition of Tilia cordata Flowers

Abstract The purpose of the study was to analyze the chemical composition of the essential oil (EO) obtained from the Tilia cordata flowers from collected (“W”) and two commercially available products (“F” and “K”). Hydro-distillation of essential oils was carried out according to the Polish Pharmacopoeia VIII. Qualitative and quantitative analysis of the essential oil was carried out by GC/MS and GC/FID. The content of essential oils in the analyzed samples was 0.07 % v/w for “K” and 0.08 % v/w for “F” and “W”. In the essential oil obtained from commercial sample “F”, 71 compounds was detected, while in the EO hydro-distilled from sample “K” and “W”, 50 and 49 compounds were identified, respectively. GC/MS analysis showed that aliphatic hydrocarbons are the main fraction occurring in the analyzed essential oils. The dominant components present in all EOs included: 6,10,14-trimethyl-2-pentadecanone (11-20 %), tricosane (6-17 %), heneicosane (3-9 %), nonanal (7 %), octadeca-9,12-dienoic acid (7 %). Among terpenoids, linalool (4 %), menthone (3 %), borneol (2 %), menthol (3 %), terpinen-4-ol (1 %), p-cymene-8-ol (2 %), carvone (6 %), E-anethole (8 %), thymol (3 %) of E-β-damascenone (4 %), methyl eugenol (4 %), neryl acetone (4 %), δ-amorphene (2 %), lilial (2 %), caryophyllene oxide (1 %), humulene epoxide II (1 %), epi-α-muurolol (1 %), kaurene (4 %) were identified.

Visualization of calcium and zinc ions in Saccharomyces cerevisiae cells treated with PEFs (pulse electric fields) by laser confocal microscopy

The aim of the present work was to visualize the areas of increased concentration of calcium and zinc ions inside Saccharomyces cerevisiae cells with the use of confocal microscopy and to make an attempt to asses semi-quantitatively their concentration within the limits of the cells. Semi-quantitative analysis revealed that fluorescence inside cells from control samples was three-times lower than that observed for cells from the sample enriched with calcium. Differences in distribution of fluorescence intensity between cells originated from the samples enriched with zinc and control samples were also observed. On the basis of the optical sections, the 3D reconstructions of ion-rich areas distribution in the cell were made. The obtained results showed that confocal microscopy is a useful technique for visualization of the areas in S. cerevisiae cells which contain higher amount of calcium and zinc and it may be also used for semi-quantitative analysis.