204 research outputs found

    The use of carboxymethylcellulose for the tartaric stabilization of white wines, in comparison with other oenological additives

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    The aim of this study was to test the effectiveness of two types of carboxymethylcellulose (CMC), at different doses, for the prevention of tartaric precipitations in two white wines (Pinot Blanc and Chardonnay), in comparison with metatartaric acid and a commercial arabic gum. After the addition of the additives to the wines, the mini-contact test was carried out and the saturation temperature was determined by Ridomi’s method. The determination of the saturation temperature was then repeated on the same trials kept at -4 °C for 10 days. Both kinds of CMC caused a significant decrease in tartaric precipitations induced by the addition of potassium bitartrate (KHT) (mini-contact test), by limiting the growth of the added KHT crystals. Their effectiveness increased with the dose, following a hyperbolic trend. The stabilizing effect of the two kinds of CMC, particularly CMC2 (more viscous), was similar to the one of metatartaric acid. Their use must be considered complementary to the cold treatment (chillproofing).

    Grape by-products: extraction of polyphenolic compounds using supercritical CO2 and liquid organic solvent - a preliminary investigation.

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    This research focussed on the exploitation of grape by-products as a source of polyphenolic compounds, which are of interest to the food, pharmaceutical and cosmetic industries. In particular, two substrates were tested: Pinot Noir grape skins and grape seeds. Pinot Noir grape skins were extracted by supercritical CO2 added with ethanol as modifier at constant temperature (45 °C) and at variable pressure (200, 300, 400 or 500 bar). The supercritical extraction kinetics of polyphenolic compounds was obtained. Grape seeds were extracted by combining supercritical (at 40 °C and 500 bar and using CO2 or CO2 added with ethanol as modifier) with liquid ethanol extraction. The supercritical technique seemed not to be really effective in extracting polyphenolic compounds; it can be anyway utilized to selectively extract grape seed oil by avoiding any solvent contamination of the matrix which can be further extracted for the recovery of polyphenolic compounds by means of liquid organic solvent

    Investigation on the TransientConditions of a Rotating Biological Contactor for Bioethanol Production

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    Alcoholic fermentations of sucrose solutions were performed in a Rotating BiologicalContactor with immobilized-yeast cells, and the results collected during the transient conditions of start-up are presented and discussed. The analysis and modeling of data constitute a preliminary semi-empirical approach to the study of dynamics of such a bioprocess. The investigation has been developed on the observations of the responses to variations in the operating conditions of substrate, product, suspended- and immobilized- cell concentrations either in the fermentation broth or within a synthetic spongy matrix

    Relationships Between Subgingival Microbiota and GCF Biomarkers in Generalized Aggressive Periodontitis

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    Aim To examine relationships between subgingival biofilm composition and levels of gingival crevicular fluid (GCF) cytokines in periodontal health and generalized aggressive periodontitis (GAP). Materials and methods Periodontal parameters were measured in 25 periodontally healthy and 31 GAP subjects. Subgingival plaque and GCF samples were obtained from 14 sites from each subject. 40 subgingival taxa were quantified using checkerboard DNA-DNA hybridization and the concentrations of 8 GCF cytokines measured using Luminex. Cluster analysis was used to define sites with similar subgingival microbiotas in each clinical group. Significance of differences in clinical, microbiological and immunological parameters among clusters was determined using the Kruskal-Wallis test. Results GAP subjects had statistically significantly higher GCF levels of interleukin-1β (IL-1β) (p\u3c0.001), granulocyte-macrophage colony-stimulating factor (GM-CSF) (p\u3c0.01), and IL-1β/IL-10 ratio (p\u3c0.001) and higher proportions of Red and Orange complex species than periodontally healthy subjects. There were no statistically significant differences in the mean proportion of cytokines among clusters in the periodontally healthy subjects, while the ratio IL-1β/IL-10 (p\u3c0.05) differed significantly among clusters in the aggressive periodontitis group. Conclusions Different subgingival biofilm profiles are associated with distinct patterns of GCF cytokine expression. Aggressive periodontitis subjects were characterized by a higher IL-1β/IL-10 ratio than periodontally healthy subjects, suggesting an imbalance between pro- and anti-inflammatory cytokines in aggressive periodontitis

    Commercial products from bio-active extractives in cypress milling residues.

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    Extractive components obtained from milling residues of white cypress were studied for chemical identity and bioactivity with a view to developing a commercial use for these components, thus increasing the value of the residues and improving the economics of cypress sawn wood production. Extracts obtained by solvent or steam extraction techniques from cypress sawdust were each fractionated by a range of techniques into groups of similar compounds. Crude extracts and fractions were screened against a range of agricultural pests and diseases, including two fungi, subterranean termites, fruit spotting bugs, two-spotted mites, thrips, heliothis, banana scab moths, silverleaf whiteflies, cattle tick adults and larvae, and ruminant gastrointestinal nematodes. Additional screening was undertaken where encouraging results were achieved, for two-spotted mites, thrips, silverleaf whiteflies, cattle tick adults and ruminant gastrointestinal nematodes. After considering degrees of efficacy against, and economic importance of, the agricultural pests, and likely production costs of extracts and fractions, the crude extract (oil) produced by steam distillation was chosen for further study against silverleaf whitefly. A useful degree of control was achievable when this oil was applied to tomato or eggplant at 0.1%, with much less harmful effects on a beneficial insect. Activity of the oil against silverleaf whitefly was undiminished 3.5 years after it was generated. There was little benefit from supplementing the extract with co-formulated paraffinic oil. From the steam distilled oil, fifty-five compounds were characterised, thirty-five compounds representing 92.478 % of the oil, with guaiol (20.8%) and citronellic acid (15.9%) most abundant. These two compounds, and a group of oxygenated compounds containing bulnesol and a range of eudesmols, were found to account for most of the activity against silverleaf whitefly. This application was recommended for first progression to commercialisation

    Signaling transduction analysis in gingival epithelial cells after infection with Aggregatibacter actinomycetemcomitans

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    Periodontal diseases result from the interaction of bacterial pathogens with the hosts gingival tissue. Gingival epithelial cells are constantly challenged by microbial cells and respond by altering their transcription profiles, inducing the production of inflammatory mediators. Different transcription profiles are induced by oral bacteria and little is known about how the gingival epithelium responds after interaction with the periodontopathogenic organism Aggregatibacter actinomycetemcomitans. In the present study, we examined the transcription of genes involved in signaling transduction pathways in gingival epithelial cells exposed to viable A.actinomycetemcomitans. Immortalized gingival epithelial cells (OBA-9) were infected with A.actinomycetemcomitans JP2 for 24 h and the transcription profile of genes encoding human signal transduction pathways was determined. Functional analysis of inflammatory mediators positively transcribed was performed by ELISA in culture supernatant and in gingival tissues. Fifteen of 84 genes on the array were over-expressed (P < 0.01) after 24 h of infection with viable A.actinomycetemcomitans. Over-expressed genes included those implicated in tissue remodeling and bone resorption, such as CSF2, genes encoding components of the LDL pathway, nuclear factor-?B-dependent genes and other cytokines. The ELISA data confirmed that granulocytemacrophage colony-stimulating factor/colony-stimulating factor 2, tumor necrosis factor-a and intercellular adhesion molecule-1 were highly expressed by infected gingival cells when compared with control non-infected cells, and presented higher concentrations in tissues from patients with aggressive and chronic periodontitis than in tissues from healthy controls. The induction in epithelial cells of factors such as the pro-inflammatory cytokine CSF2, which is involved in osteoclastogenesis, may help to explain the outcomes of A.actinomycetemcomitans infection.FAPESP [03/08598-0, 05/58903-0]Public Health Service from NIDCR [RO1DE14605
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