Influence of polyphenols isolated from <Emphasis Type="Italic">Scutellaria baicalensis</Emphasis> Georgi and <Emphasis Type="Italic">Crataegus oxyacantha</Emphasis> on the oxidative stability of cholesterol in butter stored in various conditions

The aim of the present study was to determine whether the exposure of two types of butter (A1, A2) to different conditions (4 °C and 30 °C in darkness and exposed to light 3600–3900 lx at 50 °C) could be stabilized with natural polyphenols. The polyphenols (500 ppm) added to butter included flavones of skullcap in the form of root powder, 95% pure baicalin and procyanidins from the bark of hawthorn. The rate of cholesterol oxide products (COPs) as well as the storage periods were closely connected with sample storage conditions and the type of butter. Among the polyphenols used, the flavones of skullcap proved to be stronger inhibitors of oxidation process than procyanidins of hawthorn. The storage of samples with the addition of flavones at 50 °C and exposed to light resulted in preserving 50% of cholesterol in both types of butter. The lowest amounts of COPs were formed in samples stored at 4 °C with no light exposure and, under the other conditions, in samples with flavones of skullcap added.     

Evaluation of antioxidant and antimicrobial activity of oregano (Origanum vulgare L.) preparations during storage of low-pressure mechanically separated meat (BAADER meat) from chickens

Food Science and Biotechnology - The goal of this study was to determine the effect of Origanum vulgare L. (oregano) preparations on the storage stability of vacuum-packed low-pressure mechanically...     

Enzymatic biodiesel synthesis – Key factors affecting efficiency of the process

Chemical processes of biodiesel production are energy-consuming and generate undesirable by-products such as soaps and polymeric pigments that retard separation of pure methyl or ethyl esters of fatty acids from glycerol and di- and monoacylglycerols. Enzymatic, lipase-catalyzed biodiesel synthesis has no such drawbacks. Comprehension of the latter process and an appreciable progress in production of robust preparations of lipases may soon result in the replacement of chemical catalysts with enzymes in biodiesel synthesis. Engineering of enzymatic biodiesel synthesis processes requires optimization of such factors as: molar ratio of substrates (triacylglycerols: alcohol), temperature, type of organic solvent (if any) and water activity. All of them are correlated with properties of lipase preparation. This paper reports on the interplay between the crucial parameters of the lipase-catalyzed reactions carried out in non-aqueous systems and the yield of biodiesel synthesis.     

Functional relationships between phytochemicals and drying conditions during the processing of blackcurrant pomace into powders

The effect of convective drying, microwave-vacuum drying and their combination applied to blackcurrant by-product on the quality being measured in terms of the content of phytochemicals in the powders was examined. Convective drying, along with the increase in the temperature, linearly reduced the content of anthocyanins, flavonols and chlorogenic acids. Microwave vacuum drying significantly shortened the drying time, and resulted in higher retention of bioactive compounds at higher temperatures in comparison to convection. No functional relationship was observed between bioactive compounds and the power of magnetrons thus between the processing temperature and the content of individual groups of polyphenols, apart from delphinidin-3-O-rutinoside and delphinidin-3-O-glucoside. During the dehydration of blackcurrant pomace the exponential formation of hydroxymethylfurfural was noticed. The antioxidant capacity decreased along with the increase in drying temperature and in parallel with the decrease in anthocyanins content, thus suggesting that those polyphenols considerably influence the antioxidant potential of final products.     

Betalainic and nutritional profiles of pigment-enriched red beet root (Beta vulgaris L.) dried extracts

Red beet root (Beta vulgaris L.) colourants (betalains) are available either as concentrates produced by evaporating beet juice under vacuum, or as powders made by spray-drying a concentrate. The degradation of the pigments is dependent upon temperature, duration of heat treatment, pH and water activity of a product. Recently, a new proprietary method of large-scale chromatographic purification of red beet root extract has been discovered and developed that allows the production of more concentrated betalain formulations. In order to trace the betalainic compositions of the new products in comparison to the currently in-use spray-, air- and freeze-dried concentrates, a chromatographic study on betalains and their degradation derivatives analysed by LC-DAD-ESI-MS/MS was performed. Additionally, nutritional characterisation of the extracts was accomplished.     

Mass measurements of exotic nuclei at the ESR

We plan to measure masses of exotic nuclei far from the valley of β-stability using the Experimental Storage Ring (ESR) at GSI, Darmstadt, as a time-of-flight (TOF), multi-turn mass spectrometer. For this purpose the ring must be tuned to an isochronous mode, so that the flight time per turn of an ion depends only on its mass-to-charge ratio and not on its velocity spread. For these measurements the timing detector is planned to be placed directly in the ESR to record each circulating ion.     

Role of transdermal potential difference during iontophoretic drug delivery

Potential differences have been measured during transdermal iontophoresis in order to establish the effect of voltage, as opposed to current, on cutaneous blood flow. It is known that, even in the absence of drugs, the iontophoresis current can sometimes produce increased blood flow. The role of voltage in this process is studied through single-ended measurements (between electrode and body) of the potential difference during iontophoresis with 100-microA, 20-s current pulses through deionized water, saturated 20.4% NaCl solution, 1% acetylcholine, and 1% sodium nitroprusside. It is found that the voltage needed to deliver the current varied by orders of magnitudes less than the differences in the conductance of these different electrolytes, and it is concluded that, at least for the present current protocol, the voltage as such is not an important factor in increasing the blood flow.     

Dimeric cholaphanes with disulfide spacers

New dimeric cholaphanes with disulfide spacers were prepared as potential supramolecular hosts. The spacers bind two identical steroidal subunits through C3, C3′ and C24, C24′ positions (head-to-head isomer – ‘cis-dimer’; 5) or C3, C24′ and C3′, C24 positions (head-to-tail isomer – ‘trans-dimer’; 4). Another cyclic dimer containing both disulfide and sulfide spacers in its structure (6) was also obtained.     

Adsorption of thiourea on monocrystalline silver electrodes in neutral solution

Impedance spectroscopy and radiometric method have been used in the study of thiourea (TU) adsorption on monocrystalline silver electrodes of basal indices: (1 1 1), (1 0 0) and (1 1 0) in neutral solution. The dependence of the surface concentration of TU on the electrode potential and on the bulk concentration was determined for each studied surface. From radiometric measurements it follows that adsorption of TU on silver electrodes takes place in the entire range of applied potentials. The process of adsorption is practically reversible with respect to the electrode potential (in the range of the double layer) and the bulk concentration of TU. Differential capacity of silver electrodes in 0.01 M NaClO₄ solution containing TU of concentrations from 10⁻⁶ to 5 × 10⁻⁴ M has been measured. The isotherms of TU adsorption, determined from the capacitance and radiometric measurements have been compared and the Gibbs energy of adsorption was calculated. The values of limiting surface concentration of adsorbed TU as well as the Gibbs energy of adsorption depend on the plane of Ag electrode and follow the sequence: Ag(1 1 1) > Ag(1 0 0) > Ag(1 1 0) which is in agreement with the surface density of Ag atoms.