Reduction of selected betacyanins

Betacyanins are conjugates of betalamic acid and glycosylated cyclo-DOPA which bring about the creation of a specific chromophoric system, the 1,7-diazaheptamethin chain. Betanin, a betacyanin pigment from red beet (Beta vulgaris L.), as well as its decarboxylated derivatives were subjected to reduction with the use of NaBH4. The pigment structures contain a vinyl linker which is postulated to be protonated during reaction with NaBH4. In this study, 17-decarboxybetanin and 2,17-bidecarboxy-betanin were obtained from betanin, which had been previously isolated from red beet root (Beta vulgaris L.). Purified pigments were tested in the presence of the reduction reagent while looking for the products of the reaction identified by LC-MS

Mass spectrometric detection of new betalains in Mammillaria flowers

Betacyanins are natural, red-violet betalain pigments which can be found in plenty of plants of the Cactaceae family. The Mammillaria is the widest genus of the Cactaceae family of which fruit was examined for betacyanins contents. As a result of the investigation, a new pigment structure, mammillarinin, was identified. Heretofore, no betacyanins of Mammillaria coronata flowers has been extensively studied. In this report, the results of betacyanin analysis by LC-DAD-ESI-MS/MS in the flower extract are presented

Kinetics of lactose fermentation using a recombinant saccharomyces cerevisiae strain

This work presents a multi-route, non-structural kinetic model for interpretation of ethanol fermentation of lactose using a recombinant flocculent Saccharomyces cerevisiae strain expressing both the LAC4 (coding for β-galactosidase) and LAC12 (coding for lactose permease) genes of Kluyveromyces lactis. In this model, the values of different metabolic pathways are calculated applying a modified Monod equation rate in which the growth rate is proportional to the concentration of a key enzyme controlling the single metabolic pathway. In this study, three main metabolic routes for S. cerevisiae are considered: oxidation of lactose, reduction of lactose (producing ethanol), and oxidation of ethanol. The main bioprocess variables determined experimentally were lactose, ethanol, biomass, and dissolved oxygen concentrations. Parameters of the proposed kinetic model were established by fitting the experimental data obtained in a small lab-scale fermentor with the initial lactose concentrations ranging from 5 g/dm³ to 50 g/dm³. A very good agreement between experimental data and simulated profiles of the main variables (lactose, ethanol, biomass, and dissolved oxygen concentrations) was achieved.Slovak Scientific Grant Agency ; Fundação para a Ciência e a Tecnologia (FCT

Water activity in liquid food systems : A molecular scale interpretation

Water activity has historically been and continues to be recognised as a key concept in the area of food science. Despite its ubiquitous utilisation, it still appears as though there is confusion concerning its molecular basis, even within simple, single component solutions. Here, by close examination of the well-known Norrish equation and subsequent application of a rigorous statistical theory, we are able to shed light on such an origin. Our findings highlight the importance of solute-solute interactions thus questioning traditional, empirically based “free water” and “water structure” hypotheses. Conversely, they support the theory of “solute hydration and clustering” which advocates the interplay of solute-solute and solute-water interactions but crucially, they do so in a manner which is free of any estimations and approximations

Towards ending the animal cognition war: a three-dimensional model of causal cognition

Debates in animal cognition are frequently polarized between the romantic view that some species have human-like causal understanding and the killjoy view that human causal reasoning is unique. These apparently endless debates are often characterized by conceptual confusions and accusations of straw-men positions. What is needed is an account of causal understanding that enables researchers to investigate both similarities and differences in cognitive abilities in an incremental evolutionary framework. Here we outline the ways in which a three-dimensional model of causal understanding fulfills these criteria. We describe how this approach clarifies what is at stake, illuminates recent experiments on both physical and social cognition, and plots a path for productive future research that avoids the romantic/killjoy dichotomy.Introduction Dissecting disagreement - Principles of interpretation - A big misunderstanding and the conceptual question The conceptual space of causal cognition - Causal information -- Difference‑making accounts of causality -- Geometrical–mechanical accounts - Difference‑making and geometrical–mechanical aspects of human concept of causation - Understanding causality - Parameters of causal cognition -- a) Sources of causal information -- b) Integration -- c) Explicitness From causal cognition to causal understanding - A three‑dimensional model of causal cognition - The evolution of causal cognition and the nature of causal understanding - The metrics of the model and future research Conclusio

Exercise dependence among marathon runners in relation to their demographic and training status

Introduction and purpose. Taking into account that endurance athletes might be at an increased risk for exercise dependence there is a need for monitoring the prevalence and correlates of this phenomenon in them. The aim of the study was assessing the prevalence of exercise addiction among marathon runners and identify its socio-demographic and training correlates. Material and method. A total of 132 runners ranging in age from 18–69 years old took part in the study. To assess the exercise dependence a polish version of the Exercise Dependence Scale-21 was used. Results. The results suggest that being at risk for exercise dependence concerns 12% of runners and – except of withdrawal factor - is not related to sex but is related to age. No significant differences were found between training volume groups and exercise dependence. Conclusions. More than one on ten marathoners seem to be addicted to running suggesting the need to increase knowledge on this phenomenon in this community

Genetic diversity of symbiodinium in selected corals in the Western Indian Ocean.

Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2007.Coastal communities along the east African coastline rely on coral reefs and their associated resources for food security and income. However, increases in the frequency and severity of episodes of coral bleaching have resulted in mass coral moralities in many locations around the world including the western Indian Ocean (WIO). Reef corals obligately host dinoflagellate algal symbionts of the genus Symbiodinium. Coral bleaching is caused by the loss of these symbionts from the host, resulting from a variety of stresses, the major ones being increased seawater temperature and irradiance. The Symbiodinum genus is diverse and the distribution of symbionts is influenced by the host biology, external light environment and geographic location. Ten distinct clades of Symbiodinium have been identified. Although the Caribbean and Great Barrier Reef have been studied intensively with respect to Symbiodinium diversity in many locations in the WIO Symbiodinium diversity is unknown. The aim of this study was to determine diversity, distribution and prevalence of Symbiodinium types in corals along the east African coastline. The Symbiodinium ssrDNA region was analysed using restriction fragment length polymorphism (RFLP) in order to assess the cladal diversity of Symbiodinium. The results showed all samples analysed to belong to clade C. To gain more insight into Symbiodinium genetic diversity, the ITS region was employed to assess Symbiodinium diversity at the subcladal level. Twenty ITS types were identified. The most prevalent type was found to be subclade C1. No phylogeographic structuring was found amongst the symbiont types, however, specificity of symbiont types to coral hosts was demonstrated indicating potential susceptibility to perturbations such as increased seawater temperature

The Influence of Symbiont Diversity on the Functional Biology of a Model Sea Anemone

Cnidarian–dinoflagellate symbioses, particularly those between anthozoans and dinoflagellates of the genus Symbiodinium (commonly referred to as zooxanthellae) are widespread in the marine environment. They are responsible for the formation of coral reefs and are thus of great ecological importance. In recent years there has been an increase in the frequency and severity of episodes of coral bleaching resulting in degradation and mortality of coral reefs on a global scale. In order to gain a deeper understanding of how corals can adapt to changing environmental conditions, the effect that symbiont type has on the persistence and physiology of an association needs to be ascertained. The aim of this research was to determine how different symbiont types affect the nutritional biology and intracellular physiology of the symbiosis when in association with the sea anemone Aiptasia pulchella. The specific objectives of the study were to; (1) determine whether different symbiont types are equally as adept at supporting the energetic demands of the same host; (2) determine if internal pH (pHi) is a reflection of symbiont type and whether the optimal pH for photosynthesis coincides with the host cell pHi; and (3) test the influence of Symbiodinium type on host tissue glycerol and glucose pools. In order to answer these questions, aposymbiotic (i.e. symbiont-free) sea anemones were infected with different Symbiodinium types and the relationship between symbiont type, photosynthetic performance and autotrophic potential was tested. A range of ‘normal’ and novel cnidarian–dinoflagellate symbioses was also used to measure host cell pHi and to determine the optimal pHi of isolated intact symbiosomes (i.e. the vacuoles that house the symbionts), as well as to compare the amounts of free glycerol and glucose (metabolites) present in the host tissues. Different host-symbiont combinations were found to have different photosynthetic and respiratory attributes. Earlier onset of full autotrophy (i.e. when all metabolic carbon demands of the symbiosis were met by photosynthesis) and higher CZAR values (i.e. the contribution of zooxanthellae to animal respiration) were demonstrated by symbioses hosting Symbiodinium B1 both from the original (homologous) and different (heterologous) host. The study showed that Symbiodinium types differ in their pH optima and that the optimal pHi for photosynthesis does not always match the actual measured pHi. Symbiont type was also shown to have an effect on host tissue glycerol and glucose pools, with the associations harbouring the homologous Symbiodinium B1 attaining the highest concentrations of both metabolites. Findings from this study suggest that corals may be able to maintain an association with a range of Symbiodinium types, and hence potentially switch as a consequence of bleaching. The new symbiont type may not be as nutritionally advantageous as the original type however, which could have implications for the growth and survivorship of the coral, unless it is able to supplement its carbon demands heterotrophically. The rapid proliferation of some of the heterologous Symbiodinium types (e.g. Symbiodinium E2) inside the host indicates that, after bleaching, there is potential for fast symbiont establishment. The reduced carbon contribution of these heterologous symbionts may not be a major concern should the coral be able to reinstate the more nutritionally advantageous symbiont as the dominant type during bleaching recovery. Finally, the rapid proliferation demonstrated by the heterologous Symbiodinium types and the associated metabolic cost to the host, could be an indication of the opportunistic nature of some of these types and may indicate a shift towards parasitism. It is imperative to extend this type of work to corals in the field to determine how these associations behave in nature. Also, in order to get a clearer picture of the diversity in symbiosis physiology, a wider range of Symbiodinium types needs to be investigated

Anti-Hypochlorite and Catalytic Activity of Commercially Available Moringa oleifera Diet Supplement

Aiming at the assessment of the pro-health, and especially anti-hypochlorite properties of Moringa oleifera species a representative, commercially available Moringaoleifera dietary supplement was used as a substrate for the preparation of aqueous Moringa extract. The anti-hypochlorite activity of the extract was assessed using the hypochlorite-specific coumarin-based fluorescence turn-off sensor, namely 7-diethylamino-coumarin-3-carboxylic acid (7-DCCA). This compound was synthesized via the Knoevenagel condensation of 4-diethylamino-2-hydroxybenzaldehyde with Meldrum’sacidandtheMoringaextractwasemployedasamediumandcatalyst. Moreover,thetotal phenoliccontent(TPC)aswellasthereactiveoxygenspecies(ROS)–scavengingabilityoftheaqueous Moringa extract were determined. The results obtained demonstrated the applicability of Moringa extract as an anti-hypochlorite agent. Additionally, the satisfactory yield of the 7-DCCA obtained suggests the usefulness of the extract as a catalyst and the reaction medium. The antioxidative potentialoftheextractwasnotablylowerthanthatofthestandard(TROLOX).DeterminationofTPC in 100 g of the dry weight (DW) of studied material revealed a high number of polyphones present