Black Aspergillus species as ochratoxin A producers in Portuguese wine grapes

To evaluate the incidence of fungi producing ochratoxin A (OA) in Portuguese wine grapes, a survey was conducted in 11 vineyards, from four winemaking regions each with distinct climatic conditions. From setting to the harvesting period, a total of 1,650 berries were sampled by plating methods. Out of 370 aspergilli and 301 Penicillium strains isolated, 14% of the aspergilli were OA-producing strains. None of the penicillia were OA-producing strains. The black aspergilli were predominant (90%). All Aspergillus strains were tested in vitro for OA production and all were preserved in the Micoteca da Universidade do Minho (MUM) culture collection. Most of the Aspergillus carbonarius (97%) and 4% of the Aspergillus niger aggregate strains were OA producers. Almost all ochratoxigenic strains were isolated at harvest time, mainly in the regions with a Mediterranean climate. In the vineyards sampled, the percentage of colonized berries with ochratoxigenic strains was up to 38%. The vineyards from the region with Atlantic influences, with high rainfall, exhibited the lowest occurrence of Aspergillus and ochratoxigenic strains, 0% to 10% and 0% to 2% colonized berries, respectively. Data obtained here supports the hypothesis that A. carbonarius and occasionally A. niger, are the main producers of OA in grapes. In this study, the highest incidence of these fungi occurred in vineyards with a Mediterranean climate.     

Interactions between carbon coatings and tissue

The unique properties of thin diamond layers make them perspective candidates for producing advanced micro-electronic devices, coatings for cutting tools and optics. However, due to the highest biocompatibility of carbon resulting from the presence of this element in the human body, it appears to be a potential biomaterial.Carbon, especially in the form of the nanocrystalline diamond film, have found industrial applications in the area of medical implants.The studies of carbon films as coatings for implants in surgery were aimed at the investigations of biological resistance of implants, histopathological investigations on laboratory animals, tests of corrosion resistance, measurements of mechanical properties and a breakdown test in Tyrode's solution.Different medical implants are covered by Nanocrystalline Diamond Coatings (NCD). NCD forms the barrier diffusion between implant and human environment. The research on NCD proved that diamond layers are biocompatible with living organisms.Diamond Powder Particles (DPP) is an extended surface of NCD. Biological research with diamond powder can answer the basic question: what is the influence of DPP on cells, tissues and organs in human organism?     

Evaluation of physico-chemical and sensory quality of frozen green grass pea (Lathyrus sativus L.)

The quality of grass peas (cv. Krab) intended for freezing was estimated at four degrees of seed maturity. The retention of basic physico‐chemical in dices such as dry matter, sugars, dietary fibre, total acids, total nitrogen, protein nitrogen and ash, as well as the sensory quality of frozen seeds prepared for consumption were used as the criteria in determining the overall quality value. Relative to fresh grass peas, the losses in cooked frozen seeds reached 47–64% for the content of reducing sugars, 36–53% of total sugars, 7–14% of starch, 2–4% of dietary fibre, 13–16% of total acids, 8–9% of total nitrogen and 4–6% of protein nitrogen. In cooked frozen seeds, differences between the first and the fourth maturity degree reached 47% in the case of dry matter content, 71% for starch, 166% for dietary fibre, 12% for acids, 51% for total nitrogen and 94% for protein nitrogen. The sensory quality of the cooked frozen grass peas was estimated to be from 4.17 to 4.77 on a 5‐score scale, and decreased with increasing seed maturity.     

Content of amino acids in raw and frozen broad beans (Vicia faba var. major) seeds at milk maturity stage,depending on the processing method

The aim of the present work was to evaluate the amino acid content in products obtained from broad bean seeds, at the milk maturity stage, and the quality of the protein in broad beans. The investigation included raw seeds, fresh seeds cooked to consumption consistency and two kinds of frozen products prepared for consumption: which were obtained using the traditional method (blanching the seeds before freezing) and the ready-to-eat type (cooking the seeds before freezing). Compared with the raw material, a similar (α = 0.01) content of amino acids in 100 g of the product was found in cooked fresh seeds. The seeds obtained from the ready-to-eat frozen product prepared for consumption contained higher amounts of all the amino acids than the traditional frozen product, and contained higher levels of some amino acids than were found in the product cooked from fresh seeds. Expressing the results per 16 g of N, the differences in the content of amino acids were much smaller. The limiting amino acid was cysteine with methionine (CS 74-86), the EAA index varying within the range 109–118.     

Possibility of hydrogen production during cheese whey fermentation process by different strains of psychrophilic bacteria

The aim of this study was to determine the possibility of applying psychrophilic bacteria for hydrogen production in whey biofermentation process. Experiments were conducted in 500-mL anaerobic respirometers at a temperature of 20 °C. The initial organic load of fermentation tanks reached 10 g COD/L. Depending on the experimental variant, analyses were carried out for psychrophilic bacteria isolated from underground water and from demersal lake water that represented Gammaproteobacteria class – Rahnella aquatilis (9 strains) and Firmicutes phylum: Carnobacterium maltaromaticum, Trichococcus collinsii and Clostridium algidixylanolyticum. The effectiveness of biogas production was diversified and strain-specific, ranging from 126.48 to 4737.72 mL/g bacterial biomass. The highest concentration of H₂ in biogas, ranging from 65.15% to 69.12% and effectiveness of H₂ production from 1587.47 to 3087.57 mL/g bacterial biomass, were determined for R. aquatilis strains isolated from the demersal lake water. The lowest H₂ concentration in the gaseous metabolites, i.e. 15.46% to 20.70%, was noted for bacteria of the phylum Firmicutes.     

Some Structural Properties of Spray-Dried Chitosan Microgranules

The characteristics of concurrent spray dried chitosan microgranules are presented in this article. The investigated parameters were four chemical compositions of solutions subjected to drying to produce chitosan microgranules with different structures and chemical compositions. The analysis of dried product included shape, size, density, porosity, moisture content, and solubility in water. The results show the possibilities of applying spray-drying in the formation of chitosan microgranules with required physicochemical properties.     

Content of amino acids and the quality of protein in as‐eaten green asparagus (Asparagus officinalis L.) products

The content of amino acids in fresh green spears and in three as‐eaten products was considered, i.e., in fresh asparagus after cooking and in two products obtained from frozen asparagus stored for 12 months at ?20 °C. One of the frozen products was obtained using the traditional method (blanching–freezing–frozen storage) and then cooked. The other was obtained using the modified technology (cooking–freezing–frozen storage); after the storage period the product was defrosted and heated to consumption temperature in a microwave oven. The limiting amino acid of the first order was methionine with cystine, and of the second order leucine. Essential amino acids constituted 40–43% of the total amino acid content. The dominant amino acids were aspartic acid and glutamic acid. The culinary and technological procedures applied brought about a drastic decrease (50–56% in 16 g N) in tyrosine content.     

Adenosine and 2′‐Deoxyadenosine Modified with Boron Cluster Pharmacophores as New Classes of Human Blood Platelet Function Modulators

Novel types of adenosine and 2′‐deoxyadenosine derivatives containing boron clusters at positions C2′, N6, or C8 were synthesized. The effect of these modified compounds on platelet function was studied. Modification of adenosine at the C2′ position with a para‐carborane cluster (C₂B₁₀H₁₁) results in efficient inhibition of platelet function, including aggregation, protein secretion, and P‐selectin expression induced by thrombin or ADP. These preliminary findings and the new chemistry proposed form the basis for the development of a new class of adenosine analogues that modulate human blood platelet activities.