Hplc analysis of phenolic acids in mountain germander (Teucrium montanum L) extracts

The methanol, petroleum ether, chloroform, ethyl acetate, 1-butanol and water extracts were obtained by extraction of mountain germander (Teucrium montanum L). The total phenolic content in extracts was measured by Folin-Ciocalteu method. The 1-butanol extract had the highest phenolic content (296.00 mg/g). High performance liquid chromatography (HPLC) was employed to define qualitative and quantitative content of phenolic acids in mountain germander extracts. The largest number of phenolic acids were determined in ethyl acetate and 1-butanol extracts, while these acids were not present in petroleum ether extract. The highest content of phenolic acids (28.619 mg/g) had ethyl acetate extract and gentisic acid (14.432 mg/g) was its major component. Despite of a large number of phenolic acids in 1-butanol extract their content was only 3.740 mg/g

Antioxidant and Antibacterial Activity of the Beverage Obtained by Fermentation of Sweetened Lemon Balm (Melissa offi cinalis L.) Tea with Symbiotic Consortium of Bacteria and Yeasts

Kombucha je napitak koji se tradicionalno dobiva fermentacijom zaslađenog crnog ili zelenog čaja (Camellia sinensis L.) s pomoću simbiotičke kulture bakterija i kvasaca (engl. SCOBY). U ovom je radu za pripremu napitka kombucha kao izvor dušika pri fermentaciji upotrijebljena melisa (Melissa officinalis L.). Tijekom sedmodnevne fermentacije mjereni su sljedeći parametri: pH-vrijednost, titracijska kiselost, udjeli ukupnih fenola i fenolnih spojeva, te sposobnost uklanjanja hidroksilnog (˙OH) i 1,1-difenil-2-pikrilhidrazilnog (DPPH) radikala da bi se utvrdila povezanost trajanja fermentacije s antioksidativnom i antibakterijskom aktivnošću fermentiranog napitka od melise. Određena je optimalna titracijska kiselost od 4 do 4,5 g/L, koju su potvrdili dugogodišnji konzumenti tog napitka. Ispitan je antibakterijski učinak napitaka povećane kiselosti od 8,12 g/L na jedanaest divljih bakterijskih sojeva. Rezultati pokazuju da se u proizvodnji fermentiranog napitka kombucha čaj (C. sinensis) može uspješno zamijeniti melisom. Udjel ukupnih fenola i sposobnost uklanjanja DPPH radikala bili su veći u podlozi s melisom nego u tradicionalnom napitku kombucha. Za biološku je aktivnost napitka kombucha s melisom najvjerojatnije zaslužna ružmarinska kiselina, glavni fenolni spoj u napitku. Vrijednosti EC50 pokazuju da napitak kombucha ima veću antioksidativnu vrijednost od čajnih infuzija C. sinensis L. i M. officinalis L., čemu vjerojatno pridonose metaboliti simbiotičke kulture bakterija i kvasaca. Kombucha s melisom optimalne i povećane titracijske kiselosti imala je izraženi antibakterijski učinak, ponajprije zbog prisustva octene kiseline, ali i zbog drugih sastojaka čaja te prisustva metabolita simbiotičke kulture.Kombucha is a fermented tea beverage which is traditionally prepared by fermenting sweetened black or green tea (Camellia sinensis L.) with symbiotic consortium of bacteria and yeasts (SCOBY). In this study, lemon balm (Melissa offi cinalis L.) was used as the only nitrogen source for kombucha fermentation. During the seven-day fermentation process, pH value, titratable acidity (TA), total phenolic content, phenolic compounds, and antioxidant activity against hydroxyl (˙OH) and 1,1-diphenyl-2-picrylhydrazil (DPPH) radicals were measured to detect the connection between the fermentation time and antioxidant and antibacterial activities of lemon balm kombucha. Antibacterial activity of fi nished beverages with optimum acidity (TA=4–4.5 g/L), the value which is confi rmed by long-time kombucha consumers, and enhanced acidity (TA=8.12 g/L) was tested against eleven wild bacterial strains. The results showed that lemon balm could be successfully used as an alternative to C. sinensis L. for kombucha fermentation. Total phenolic content and antioxidant activity against DPPH radicals of lemon balm fermentation broth were higher than those of traditional kombucha. Rosmarinic acid is the main phenolic compound of the lemon balm-based kombucha that probably provides biological activity of the beverage. Judging from the EC50 values, kombucha beverages exhibited higher antioxidant activities compared with C. sinensis L. and M. offi cinalis L. infusions, which can probably be ascribed to SCOBY metabolites. Lemon balm kombucha with both optimum and enhanced acidity showed antibacterial activity, which can be primarily ascribed to acetic acid, but also to some other tea components and SCOBY metabolites

Network e-Volution

Modern society is a network society permeated by information technology (IT). As a result of innovations in IT, enormous amounts of information can be communicated to a larger number of recipients faster than ever before. The evolution of networks is heavily influenced by the extensive use of IT, which has enabled co-evolving advanced quantitative and qualitative forms of networking. Although several networks have been formed with the aim to reduce or deal with uncertainty through faster and broader access to information, it is in fact IT that has created new kinds of uncertainty. For instance, although digital information integration in supply chains has made production planning more robust, it has at the same time intensified mutual dependencies, thereby actually increasing the level of uncertainty. The aim of this working paper is to investigate the aspects of evolving networks and uncertainty in networks at the cutting edges of different types of networks and from the perspective of different layers defining these networks

Chief digital officers:An analysis of the presence of a centralized digital transformation role

By appointing a chief digital officer (CDO), firms decide for a central role responsible for their digital transformation. While CDOs have recently appeared in the C-suites of firms across the globe, the current literature lacks insights into the specific antecedents of CDO presence. Grounded in the peculiarities of the digital age, we provide theoretical arguments explaining how the decision to centralize digital transformation responsibilities might be related to transformation urgency and coordination needs. Empirical analyses based on a panel data set of 913 U.S. and European firms support that transformation urgency and coordination needs predict CDO presence. An additional analysis of moderating temporal effects reveals that, over time, the effect of transformation urgency is weakened and the effect of coordination needs on CDO presence is strengthened. We discuss implications for research and practice regarding the antecedents of CDO presence, TMT research more generally, and centralization in the digital age

Chemical composition and antioxidant activity of berry fruits

The main chemical composition, contents of total phenolic (TPh), total flavonoid (TF), and total monomeric anthocyianin (TMA), as well as the antioxidant activity of two raspberry cultivars (Meeker and Willamette), two blackberry cultivars (Čačanska bestrna and Thornfree) and wild bilberry were studied. The raspberry cultivars had the highest total solids among fruits investigated. Bilberry fruits had the highest sugar-to-acid ratio. Blackberry fruits were richer in crude fibers (cellulose) in comparison to raspberry and bilberry fruits. The content of pectic substances was highest in the bilberry. Also, bilberry had a highest content of TPh (808.12 mg GAE/100 g FW), TF (716.31 mg RE/100 g FW) and TMA (447.83 mg CGE/100 g FW). The antioxidant activity was evaluated spectrophotometrically, using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity assay. The DPPH free radical scavenging activity, expressed as the EC50 value (in mg of fresh weight of berry fruit per ml of the reaction mixture), of bilberry (0.3157 ± 0.0145 mg/ml) was the highest. These results also showed that the antioxidant value of 100 g FW bilberry, raspberry - Willamette, raspberry - Meeker, blackberry - Čačanska bestrna and blackberry - Thornfree is equivalent to 576.50 mg, 282.74 mg, 191.58 mg, 222.28 mg and 272.01 mg of vitamin C, respectively. There was a significant positive correlation between the antioxidant activities and content of total phenolics (RTPh 2=0.9627), flavonoids (RTF 2=0.9598) and anthocyanins (RTMA 2=0.9496) in berry fruits. [Projekat Ministarstva nauke Republike Srbije, br. TR 31044

Cranberry: A good source of natural antioxidants

The influence of extracts of cranbeny fruit and mixed tea (containing 40% cranberry) on stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals has been investigated by electron spin resonance (ESR) spectroscopy. All investigated extracts possess very high antioxidant activity, which increased dose-dependently at mass concentrations ranging from 0.5 to 3.5 mg/ml. The high contents of phenolic s (3.60-4.52 mg/g), anthocyanins (0.23-1.52 mg/g), flavan-3-ols (1.25-3.05 mg/g) and vitamin C (0.07-0.15 mg/g) in investigated extracts indicated that these compounds significantly contributed to the antioxidant activity. All these results show that the extracts of cranberry fruit and mixed tea can be used as easily accessible source of natural antioxidants and as a possible food supplement

Pentachlorobenzene sorption onto sediment organic matter

Sorption behaviour of pentachlorobenzene on four humic acids (HAs) and two humins extracted from a take sediment was studied. The objective was to provide a better understanding of the sorption mechanism of pentachlorobenzene onto sediment organic matter. Ten HAs were obtained by progressive sequential extraction of a sediment sample, while the residue after extraction was separated into two humin fractions on the basis of organic carbon content. The structural heterogeneity of the HAs and humins was characterized using elemental analysis and diffuse reflectance Fourier transform infrared spectroscopy. All sorption isotherms, fitted to a Freundlich equation, were nonlinear. For the HAs, isotherm linearity increased from 0.902 for the first extracted HA to 0.945 for the tenth HA, showing increase in the nonlinearity of the associated sorption isotherms with increasing HA aromaticity. On the other hand, a positive correlation between sorption coefficient and aliphaticity of the HAs supports the hypothesis that the non-polar aliphatic domains in sediment organic matter strongly affect the sorption of hydrophobic organic compounds. Both humin samples showed greater nonlinearity than the HAs, with the greatest degree of nonlinearity (0.827) for the humin with lower organic carbon content, while humin with higher organic carbon content showed the greatest pentachlorobenzene sorption affinity. It has been suggested that sorption processes may be strongly affected by the physical conformation of, and accessibility to, organic matter, as demonstrated by the high K-oc and low n of humin samples. (c) 2007 Elsevier Ltd. All rights reserved

Pentachlorobenzene sorption onto sediment organic matter

Sorption behaviour of pentachlorobenzene on four humic acids (HAs) and two humins extracted from a take sediment was studied. The objective was to provide a better understanding of the sorption mechanism of pentachlorobenzene onto sediment organic matter. Ten HAs were obtained by progressive sequential extraction of a sediment sample, while the residue after extraction was separated into two humin fractions on the basis of organic carbon content. The structural heterogeneity of the HAs and humins was characterized using elemental analysis and diffuse reflectance Fourier transform infrared spectroscopy. All sorption isotherms, fitted to a Freundlich equation, were nonlinear. For the HAs, isotherm linearity increased from 0.902 for the first extracted HA to 0.945 for the tenth HA, showing increase in the nonlinearity of the associated sorption isotherms with increasing HA aromaticity. On the other hand, a positive correlation between sorption coefficient and aliphaticity of the HAs supports the hypothesis that the non-polar aliphatic domains in sediment organic matter strongly affect the sorption of hydrophobic organic compounds. Both humin samples showed greater nonlinearity than the HAs, with the greatest degree of nonlinearity (0.827) for the humin with lower organic carbon content, while humin with higher organic carbon content showed the greatest pentachlorobenzene sorption affinity. It has been suggested that sorption processes may be strongly affected by the physical conformation of, and accessibility to, organic matter, as demonstrated by the high K-oc and low n of humin samples. (c) 2007 Elsevier Ltd. All rights reserved