Monika Sujka

Ultrasonic modification of starch – Impact on granules porosity

Rice, corn, wheat, and potato starch granules suspended in water or ethanol were treated with ultrasounds at frequency of 20kHz and power 170W for 30min. Porosity of starch was investigated in terms of specific surface area (SBET), average pore size and pore size distribution using low-temperature nitrogen adsorption method. The significant increase of SBET was noted for all the studied starches sonicated in water and for potato starch modified in ethanol. Ultrasonic treatment influenced the average diameter of mesopores (2nm<width<50nm) differently. The significant increase of this parameter was noted for wheat and rice starches suspended in ethanol and for potato starch granules suspended in water, but in the case of corn starch, the obtained value was slightly lower after sonication in water. Modification of starch with ultrasounds resulted in the formation of new pores in the studied range of diameter.

Effect of pulse electric fields (PEF) on accumulation of magnesium and zinc ions in Saccharomyces cerevisiae cells

Cultures of Saccharomyces cerevisiae were treated with PEF to improve simultaneous accumulation of magnesium and zinc ions in the biomass. The results showed that the ions concentration in the medium and their mutual interactions affect accumulation in cells. Increasing the concentration of one ion in the medium reduced the accumulation of the second one, in the control as well as in the cells treated with PEF. Under optimized conditions, that is, on 15 min exposure of the 20 h grown culture to PEF of 5.0 kV/cm and 20 μs pulse width, accumulation of magnesium and zinc in yeast biomass reached maximum levels of 2.85 and 11.41 mg/gd.m., respectively, To summarize, optimization of ion pair concentration and PEF parameters caused a 1.5 or 2-fold increase of magnesium and zinc accumulation, respectively, in S. cerevisiae.

Bioaccumulation of the Selected Metal Ions in Saccharomyces cerevisiae Cells Under Treatment of the Culture with Pulsed Electric Field (PEF)

The obtained results demonstrated an influence of PEF on increase in accumulation of various ions in S. cerevisiae cells. Optimization of particular PEF parameters and ions concentrations in the medium caused twofold increase in accumulation of magnesium and zinc ions and 3.5-fold higher accumulation of calcium ions in the cells. In the case of ion couple, accumulation of magnesium and zinc was, respectively, 1.5-fold and twofold higher in comparison to the control cultures. Yeast cells biomass enriched with Mg2+, Zn2+, Ca2+ as well as Mg2+ and Zn2+ (simultaneously) may be an alternative for pharmacological supplementation applied in deficiency of these cations.

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.