RIOFH - Repository of Institute of General and Physical Chemistry
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Application of the GC/MS technique in environmental analytics: Case of the essential oils
No full textEssential oils (EOs) are a complex mixture of different classes of compounds. They are widely applied today in different branches of industry, e.g., food and pharmaceutical industries. EOs are also applied in folk medicine and in the production of perfumes. Because of their significance, it is very important to develop a method for their analysis. To do so, gas chromatography coupled with mass spectrometry (GC/MS) was applied to establish the method. Commonly applied nonpolar column (HP 5-MS) was replaced with the polar one (TR WAX-MS) with polyethylene glycol as a stationary phase. Different analytical standards have been used for the creation of the calibration curves. Results showed that the polar column separated the compound more efficiently than the nonpolar column. The analysis was longer with the polar than with nonpolar column, but the polar stationary phase provided separation based on the polarity of the analyzed compounds, which ensured good separation of isomers and derivatives. To conclude, application of the polar column may provide a better result that is highly desirable, thus its usage for the analysis of EOs is encouraged
Health impact of the commercially cultivated mushroom Agaricus bisporus and the wild-growing mushroom Ganoderma resinaceum - A comparative overview
No full textThe health promoting effects of hot water extracts obtained from fruiting bodies of the commercially cultivated mushroom Agaricus bisporus (AbHW) and the wild-growing mushroom Ganoderma resinaceum (GrHW) originating from northern Serbia are presented in this research. These abilities were compared in vitro by the prevention of lipid peroxidation (LPx) in a linoleic acid model system, inhibition of the angiotension converting I enzyme (ACE) that could help in the maintenance of a normal blood pressure level and strengthening the ability of the central cholinergic neuron by inhibiting the activity of acetylcholinesterase (AChE). Cytotoxic activities were observed towards selected human malignant (HeLa and K562) cell lines and normal-human peripheral blood mononuclear cells (PBMC). GrHW contains higher phenolics (5.9 g (100 g)(-1)), inhibition of LPx (EC50 = 1.07 mg mL(-1)), ACE (IC50 = 0.54 mg mL(-1)) and AChE (IC50 = 0.37 mg mL(-1)), and exhibited a significant selectivity in the antitumour action against HeLa (IC50 = 0.14 mg mL(-1)) and K562 (IC50 = 0.11 mg mL(-1)) cells. AbHW contained higher total protein (6.4 g (100 g)(-1)), carbohydrate (75.4 g (100 g)(-1)) and beta-glucan (55.1 g (100 g)(-1)) contents and induced significant proliferation of healthy PBMC from 152-116 % in the concentration range of 0.047-0.187 mg mL(-1). The difference in the biological activity of the extracts provides guidance on their use as functional food
QSRR Model for Predicting Retention Indices of Geraniol Chemotype ofThymus serpyllumEssential Oil
No full textA total of 26 experimentally obtained retention indices on a logarithmic scale (log RI) fromThymus serpyllumessential oil were used to build a robust predictive model. The selected descriptors were used as inputs of an artificial neural network model to build a predictive quantitative structure-retention time relationship model. The coefficient of determination for the training cycle was 0.977, indicating that this model could be used for the prediction of retention indices forT. serpyllumessential oil compounds. These 26 compounds comprise about 99.8 % of the total oil, but among them only 6 compounds had the average relative concentration over 1 percent: geraniol (63.4 %), nerol (orcis-geraniol) (18.9 %), geranyl acetate (4.7 %),trans-caryophyllene (4.6 %), beta-bisabolene (2.0 %) and geranial (1.2 %). According to these results, it can be concluded thatT. serpyllumfrom village Sesalac (Serbia) belongs to geraniol chemotype, in total 82.3 % in both,transandcisforms (63.4 % and 18.9 %, respectively)
Vacuum drying of sweet cherry: Artificial neural networks approach in process optimization
No full textSweet cherries were vacuum-dried and the process was optimized with relative antioxidant activity index (RACI), standard score (SS), and artificial neural network (ANN) approach. Investigated input parameters were drying temperature and pressure, while moisture content, water activity, total phenolic, flavonoid and anthocyanins content, and antioxidant activity (FRAP, DPPH, and ABTS test) were analyzed as output parameters. The obtained mean value ofR(2)(0.872) indicates that the ANN investigated in this research could be successfully applied for describing the sweet cherry vacuum drying in the range of temperatures from 50 to 70 degrees C and of pressures from 20 to 200 mbar. The optimized sweet cherries vacuum-dried process presents significant support for the possibility toward application of vacuum drying for sweet cherries in industrial conditions. According to ANN results, it is possible to take any combination of input parameters and calculate the output parameters observed in this research. Practical applications In the framework of this research, the artificial neural network (ANN) were applied on sweet cherries vacuum drying and as a main result the optimized vacuum drying process was obtained. Such optimized process presents significant base for the possibility toward application of sweet cherries vacuum drying in industrial conditions. This is enabled, since according to ANN results obtained in this research it is possible to take any set of input vacuum drying parameters (T: 50-70 degrees C and p: 20-200 mbar) and calculate the values of the output parameters (moisture content, water activity, total phenolic, flavonoid and monomeric anthocyanin content, and antioxidant activity) observed in this research
Response of microbial community composition in soils affected by coal mine exploitation
No full textSurface mining activities, despite their benefits, lead to the deterioration of local and regional environmental quality and play a role in global ecosystem pollution. This research aimed to estimate the culturable microbial population structure at five locations near the opencast coal mine "Kakanj" (Bosnia and Herzegovina) via agar plate and phospholipid fatty acids (PLFA) method and to establish its relationship to the physical and chemical properties of soil. Using the ICP-OES method, the heavy metal pollution of all examined locations (overburden, former grass yard, forest, arable soil, and greenhouse) was observed. Substantial variations among the sites regarding the most expressed indicators of heavy metal pollution were noted; Cr, Pb, Ni, and Cu content ranged from 63.17 to 524.47, 20.57 to 349.47, 139.13 to 2785.67, and 25.97 to 458.73 mg/kg, respectively. In the overburden sample, considerable low microbial activity was detected; the bacterial count was approximately 6- to 18-fold lower in comparison with the other samples. PLFA analysis showed the reduction of microbial diversity, reflected through the prevalence of normal and branched saturated fatty acids, their ratio (ranged from 0.92 to 7.13), and the absence of fungal marker 18:2 omega 6 fatty acid. The principal component analysis showed a strong negative impact of heavy metals Na and B on main microbial and PLFA profiles. In contrast, stock of main chemical parameters, including Ca, K, Fe, and pH, was positively correlated with the microbial community structure
The Antimicrobial Activities of Silver Nanoparticles Synthesized from Medicinal Mushrooms
No full textCrude polysaccharide extracts derived from Agaricus bisporus (A), A. brasiliensis (B), and Phellinus linteus (P) were used for the synthesis of silver nanoparticles (AgNPs, labeled AAgNP, BAgNP, PAgNP, respectively) UV and FT-IR spectra, size distribution, and zeta potential of the respective particles were recorded, and TEM and SEM-EDS characterization was done. UV-Vis spectroscopy showed maximum absorbance at 415 mu for A, at 400 nm for P, and at 420 nm for B. SEM-EDS analysis showed BAgNP to consist of almost 90% of silver, while silver content in AAgNP and PAgNP was much lower, 46.5 and 52.3%, respectively. Individual extracts as well as the Ag-NPs were tested against a panel of clinically isolated and ATCC derived pathogens. In almost all cases minimum inhibitory concentration (MIC) was significantly lower than those of antibiotics, suggesting up to 100 times more effectivity. BAgNP, PAgNP, and AAgNP appeared very active against Pseudomonas aeruginosa ATCC 27853 (MIC: 0.19, 0.19, 0.97 mu g/mL, respectively). The same nanoparticles were also very effective toward Candida albicans ATCC 10231 (MIC: 0.39, 0.78, 0.97 mu g/mL, respectively). Our study indicates that the bactericidal effect of PAgNP, AAgNP, BAgNP on E. coli 25922 ATCC (MBC: 1.56, 0.97, 6.25 mu g/mL, respectively) is significantly more pronounced than that of amoxicillin. A pure solution of colloidal silver nanoparticles showed significantly weaker microbiostatic/microbiocidal potential than all tested mushroom extracts' AgNPs, as well as amoxicillin. Silver nanoparticles made with extracts of A, B, and P seem welcome as an addition to the inventory of antimicrobial compounds used in clinical medicine against bacterial and yeast infection
Polyphenol profile of buckwheat honey, nectar and pollen
No full textA focus of research in recent years is the comparison of honey as the final product of bees with pollen and nectar of the plant from which the honey originates, as the main food source for bees. Buckwheat honey is recognized as a nutritionally valuable product, which provides a scientifically proven health benefit and is confirmed as a functional food. The quality of this type of honey is attributed to high levels of phytochemicals in buckwheat. The purpose of this study was the examination of similarity between buckwheat honey and buckwheat nectar and pollen, as well as simultaneous investigation of their chemical profiles and the origin of the honey. The phenolic profile of buckwheat pollen showed a lower number of flavonoids and phenolic acids than those of nectar and honey samples, but confirmed the presence of the most characteristic polyphenols derived from the buckwheat plant. The notable difference was found to be the presence of (epi)catechin units, its galloylated derivatives and procyanidin dimers, which were not present in honey. Honey polyphenols displayed a pronounced correlation with those of nectar, but not with those of pollen. Finally, by comparing the polyphenolic profiles of honey, nectar and pollen sharing the same geographical origin, new data could be provided for a potential assessment of the botanical origin of buckwheat honey
A textile-based microfluidic platform for the detection of cytostatic drug concentration in sweat samples
No full textThis work presents a new multilayered microfluidic platform, manufactured using a rapid and cost-effective xurography technique, for the detection of drug concentrations in sweat. Textile fabrics made of cotton and polyester were used as a component of the platform, and they were positioned in the middle of the microfluidic device. In order to obtain a highly conductive textile, the fabrics were in situ coated with different amounts of polyaniline and titanium dioxide nanocomposite. This portable microfluidic platform comprises at least three layers of optically transparent and flexible PVC foils which were stacked one on top of the other. Electrical contacts were provided from the edge of the textile material when a microfluidic variable resistor was actually created. The platform was tested in plain artificial sweat and in artificial sweat with a dissolved cytostatic test drug, cyclophosphamide, of different concentrations. The proposed microfluidic device decreased in resistance when the sweat was applied. In addition, it could successfully detect different concentrations of cytostatic medication in the sweat, which could make it a very useful tool for simple, reliable, and fast diagnostics
Molecular identification and characterisation of aspergillus flavus isolates originating from Serbian wheat grains
No full textDuring previous years. regarding the shifts in climate conditions in temperate region, such as occurrence of high temperatures and prolonged drought, increased occurrence frequencies of Aspergillus flavus and aflatoxins in cereal grains were recorded. A reliable and accurate identification of the fungi is of great importance for evaluating the microbiological risks of contamination. The essential point of the present investigation was molecular characterisation and identification of A. flavus isolates originating from common wheat and spelt grains collected after harvest during the period of three years (2015-2017) in Northern Serbia. A holistic approach that included PCR amplification of two DNA genomic regions and PCR-RFLP assay followed by fragment length analysis, provided complete and comprehensive characterisation of A. Amiss isolated from wheat grains. The presented results indicate that there was no difference among the tested A. spergillus isolates on the molecular-genetic level. All 38 strains were identified as A. flavus by sequencing of combined ITS region and beta-tubulin gene fragments (ace. no.: MH582473 to MH582510). PCR-RFLP method in combination with a Lab-on-a-chip (LoaC) electrophoresis can be successfully used to rapidly identify A. flavus isolates
Application of porcini mushroom (Boletus edulis) to improve the quality of frankfurters
No full textThe antioxidant and antimicrobial properties of Boletus edulis decoction and the effect of mushroom addition on the physicochemical and microbiological properties of frankfurters during refrigerated storage were studied. The addition of mushroom delayed the increase in the total number of aerobic mesophilic microorganisms during the storage. The incorporation of B. edulis in cooked sausages resulted in the significantly higher hardness of frankfurters in comparison with control, during chilled storage. Mushroom addition significantly affected the color of sausages throughout storage, but no deficiencies in sensory acceptance test were obtained. Generally, this mushroom can be used as a natural antioxidant to interfere with microorganism growth and extend the shelf life of cooked pork sausages during refrigerated storage. Practical applications In this study, the addition of B. edulis has proven to be a potent antioxidant and antimicrobial ingredient that extends the shelf life of frankfurters. That could be an interesting finding in potentially reducing or replacing commercial antioxidants with a natural, healthier variant of food additives