Determination of flavan-3-ols and trans-resveratrol in grapes and wine using HPLC with fluorescence detection

Concentrations of trans-resveratrol, catechin and epicatechin were analyzed in musts and wines produced from seven red and four white grape cultivars from various wine growing regions of Turkey. Phenolics were quantified using an HPLC method optimized for the separation of wine phenolics. Wine samples contained higher phenolics levels than the corresponding musts. With the exception of Semillion, white wines and musts contained lower concentrations of phenolics than red wines and musts. However, the white cultivar Semillion had the highest concentrations of catechin and epicatechin among all wine and must samples. Semillion wine catechin and epicatechin were 13.7 and 11.8 mg/L, respectively. The highest level of trans-resveratrol among the white cultivars was found in Narince wine (1.93 mg/L). Within the red wine and must cultivars, Bo?azkere, Öküzgozü, and Cabernet contained the highest concentrations of flavan-3-ols and trans-resveratrol. Catechin was the major phenolic in all wines and most musts. Epicatechin was the major phenolic in 6 of the 11 must samples, but none of the wine samples. trans-Resveratrol was generally found in lowest concentrations in both wines and musts.     

The effect of highly purified eicosapentaenoic and docosahexaenoic acids on monocyte phagocytosis in man

The n-3 fatty acids (FA) from marine sources are known to exert antiinflammatory effects on monocyte function. There is still controversy whether n-3 FA may increase the susceptibility to infections. The present study was designed to assess the effect of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHa) on monocyte phagocytosis and respiratory burst activity. Fifty-eight healthy men were randomized to take a daily supplement of 3.8 g highly purified EPA (n=20), 3.6 g DHA (n=19), or corn oil (n=19) for 7 wk. Mononuclear leukocytes were collected, isolated, and cryopreserved prior to and after dietary supplementation. Paired samples were analyzed in the presence of autologous serum in a crossover design. Monocyte phagocytosis and respiratory burst activity were measured by flow cytometry after ingestion of Escherichia coli. Monocytes retained their phagocytic ability and respiratory burst activity after supplementation. No reduction in internalization of bacteria was registered. Dietary n-3 FA and particularly EPA improved bacterial adherence to the monocyte surface. In the crossover experiments, there was an adverse effect of serum enriched with n-3 FA on bacterial adherence. We conclude that monocytes retain their phagocytic potential after supplementation with purified EPA and DHA.     

Aroma volatile compositions of high- and low-aromatic guava varieties

BACKGROUND: The traditional guava variety cultivated in Israel, ‘Ben Dov’, emits a very strong odour, whereas some newly bred varieties have a mild odour. In this study the aroma profile composition of the high‐aromatic ‘Ben Dov’ variety was compared with those of four new low‐aromatic varieties. RESULTS: Overall, using gas chromatography/mass spectrometry, a total of 30 aroma volatiles were detected in fresh ripe guava fruit: 15 of them were specifically detected only in the high‐aromatic ‘Ben Dov’ variety, 13 were detected in both the high‐ and low‐aromatic varieties and two were detected only in the new low‐aromatic varieties. Interestingly, 11 out of the 15 volatiles specifically detected in ‘Ben Dov’ were esters that contribute sweet, tropical and fruity notes. In contrast, ten out of 13 detected terpenes and two detected aldehydes, contributing green, spicy, herbal and woody notes, were common to both the high‐ and low‐aromatic varieties. CONCLUSION: Based on these findings, it is concluded that accumulation of esters is the main reason why the traditional ‘Ben Dov’ guava variety emits such a strong tropical fruity odour. In contrast, the newly bred low‐aromatic guava varieties did not synthesise esters at all and thus lacked fruity aromatic notes. Overall, the results of this study point out the important role of esters in forming tropical fruity guava odours. Copyright © 2011 Society of Chemical Industry     

Effects of stochastic energy prices on long-term energy-economic scenarios

In view of the currently observed energy prices, recent price scenarios, which have been very moderate until 2004, also tend to favor high future energy prices. Having a large impact on energy-economic scenarios, we incorporate uncertain energy prices into an energy systems model by including a stochastic risk function. Energy systems models are frequently used to aid scenario analysis in energy-related studies. The impact of uncertain energy prices on the supply structures and the interaction with measures in the demand sectors is the focus of the present paper.

For the illustration of the methodological approach, scenarios for four EU countries are presented. Including the stochastic risk function, elements of high energy price scenarios can be found in scenarios with a moderate future development of energy prices. In contrast to scenarios with stochastic investment costs for a limited number of technologies, the inclusion of stochastic energy prices directly affects all parts of the energy system. Robust elements of hedging strategies include increasing utilization of domestic energy carriers, the use of CHP and district heat and the application of additional energy-saving measures in the end-use sectors. Region-specific technology portfolios, i.e., different hedging options, can cause growing energy exchange between the regions in comparison with the deterministic case.     

Proportional control?

In modern societies, legal regulations define legal norms within a wide range of life situations; from accepting paternity to paying inheritance tax. Along with every regulation, detailed and complicated requirements are often defined for us to follow, and it is considered criminal not to observe them. Due to the complexity of rules and regulations in modern sources, control measures within fields where ordinary people interact with decision-making bodies may create uncertainty among and resistance by “law-abiding citizens”. This article will focus on control measures within Norwegian public mass administration. An important characteristic of these systems is that many of the legal rules which govern them and which are traditionally found in paper format have been transformed into computer program code. I will explicitly refrain from addressing issues concerning police investigation, state security, and control in situations where providing services (health, education, etc.) constitutes the main activity. When control is discussed in this context, control of both the computerized and manual routines is important because they are so closely connected. Information technology makes available a range of new control measures for ensuring that citizens submit correct information in the course of a decision-making process and the focus here is on this use of information technology.     

CO hydrogenation over supported cobalt catalysts: FTIR and gravimetric studies

The hydrogenation of CO over supported cobalt catalysts has been studied using in situ FTIR spectroscopy and gravimetry at P = 6 bar, T = 473–723 K and H₂/CO = 2–3. On both silica- and alumina-supported catalysts IR absorption bands corresponding to linearly adsorbed CO on metallic cobalt were observed. On alumina an additional pair of bands at lower frequencies was attributed to bridge-bonded CO. Absorption bands corresponding to adsorbed hydrocarbons (3050–2700 cm^?1) and to oxygen containing species (1800–1200 cm^?1) were found to correspond to adsorbed products or unreactive species. The gravimetric studies showed a significant difference between the supports. On the silica-supported catalyst the weight uptake decreased with increasing temperature (473–573 K). The weight increase during reaction was attributed to adsorbed hydrocarbon reaction products. On the alumina-supported catalyst the weight uptake increased with increasing temperature, and there was also a significant weight increase with the support alone. Most of the weight uptake can be attributed to the formation of stable formate and carbonate species on the alumina support. At 723 K the deposits formed were stable in H₂, and the shape of the curves indicated different mechanisms for deposition of material. In particular the Co/Al₂O₃ sample showed a very high and linear rate of weight gain, which was an order of magnitude higher than for the other samples.     

Nonlinear analysis of oil pipelines by potential minimization

The problem of finding the deformed shape of a structure can be formulated as finding the minimum of the total potential for the system defined by the structure and the loads acting on it. By defining unknown displacements as free variables and the total potential as objective function in a minimization problem, the displacements can be found by a minimization technique. This method is applied to perform a static analysis of offshore pipelines during installation, which is a geometric nonlinear problem.

The theoretical foundation of this method is briefly described and the relationship to an iterative finite element formulation is pointed out.

Expressions for the total potential of the pipeline system, defined by the strain energy and the potential of acting forces are presented.

Two minimization techniques are used. For this problem, where gradients are available with reasonable effort, a gradient method based upon Fletcher-Powell's search technique has been found faster and more accurate than Powell's direct search technique.

A computer program based upon the method presented is developed and the results are encouraging concerning both convergency and computational effort.