Ageing profiling of craft beers: a sensorial and chemical overview

One of the main differences between craft and commercial beers is the presence of active yeast in the bottle, which can have high impact on beer stability during shelflife. For this reason, sensory and chemical beer profiling during storage is of upmost importance when focusing quality control. This study investigated the changes that occur during the storage/ageing of four different craft beers and two commercial beers, which were used for comparison. Sensory analysis of capped and corked beers was performed overtime accompanied by sampling for minor volatiles analysis. Craft beers showed an aromatic profile more intense than the commercial beers and kept the profile similar after six months, as well as the commercial beers. Fruity, floral and caramel were among the main descriptors found for the beers studied, and maintained their intensity during the analysis time. Minor compounds analysis was coherent with the aromatic profiles obtained, as well as those portrayed in the literature, however most of the main ageing markers reported were not found in the beers studied. Among the minor volatiles studied esters concentration varied differently depending on beer type and alcohols, fatty acids, carbonyl compounds and pyrazines concentrations increased for all beers. However, variations on minor volatiles composition had low impact on sensorial perception. The results allowed to conclude that the craft beers maintained the sensory quality as a commercial beer, over a six month period, with the benefit of having more intense flavors and aromas when compared to the commercial beers studied.info:eu-repo/semantics/publishedVersio

Development and characterization of an environmentallyfriendly process sequence (autohydrolysis and organosolv) for wheat straw delignification

The present work describes the delignification of wheat straw through an environmentally friendly process resulting from sequential application of autohydrolysis and organosolv processes. Wheat straw autohydrolysis was performed at 180°C during 30 min with a liquid–solid ratio of 10 (v/w); under these conditions, a solubilization of 44% of the original xylan, with 78% of sugars as xylooligosaccharides of the sum of sugars solubilized in the autohydrolysis liquors generated by the hemicellulose fraction hydrolysis. The corresponding solid fraction enrichment with 63.7% of glucan and 7.55% of residual xylan was treated with a 40% ethanol and 0.1% NaOH aqueous solution at a liquid–solid ratio of 10 (v/w), with the best results obtained at 180°C during 20 min. The highest lignin recovery, measured by acid precipitation of the extracted lignin, was 3.25 g/100 ml. The lignin obtained by precipitation was characterized by FTIR, and the crystallinity indexes from the native cellulose, the cellulose recovered after autohydrolysis, and the cellulose obtained after applying the organosolv process were obtained by X-ray diffraction, returning values of 21.32%, 55.17%, and 53.59%, respectively. Visualization of the fibers was done for all the processing steps using scanning electron microscopy.The authors thank Professor Juan Carlos Parajo from University of Vigo, for the assistance in the materials preparation under autohydrolysis process as well as the ALBAN program for the PhD fellowship support

Agent based modelling helps in understanding the rules by which fibroblasts support keratinocyte colony formation

Background: Autologous keratincoytes are routinely expanded using irradiated mouse fibroblasts and bovine serum for clinical use. With growing concerns about the safety of these xenobiotic materials, it is desirable to culture keratinocytes in media without animal derived products. An improved understanding of epithelial/mesenchymal interactions could assist in this. Methodology/Principal Findings: A keratincyte/fibroblast o-culture model was developed by extending an agent-based keratinocyte colony formation model to include the response of keratinocytes to both fibroblasts and serum. The model was validated by comparison of the in virtuo and in vitro multicellular behaviour of keratinocytes and fibroblasts in single and co-culture in Greens medium. To test the robustness of the model, several properties of the fibroblasts were changed to investigate their influence on the multicellular morphogenesis of keratinocyes and fibroblasts. The model was then used to generate hypotheses to explore the interactions of both proliferative and growth arrested fibroblasts with keratinocytes. The key predictions arising from the model which were confirmed by in vitro experiments were that 1) the ratio of fibroblasts to keratinocytes would critically influence keratinocyte colony expansion, 2) this ratio needed to be optimum at the beginning of the co-culture, 3) proliferative fibroblasts would be more effective than irradiated cells in expanding keratinocytes and 4) in the presence of an adequate number of fibroblasts, keratinocyte expansion would be independent of serum. Conclusions: A closely associated computational and biological approach is a powerful tool for understanding complex biological systems such as the interactions between keratinocytes and fibroblasts. The key outcome of this study is the finding that the early addition of a critical ratio of proliferative fibroblasts can give rapid keratinocyte expansion without the use of irradiated mouse fibroblasts and bovine serum

Conhecendo espécies de planta da Amazônia: Tamanqueira (Zanthoxylum rhoifolium Lam. - Rutaceae).

Taxonomia; Nomes populares; Como reconhecer a espécie; Ocorrência na Amazônia brasileira; Usos; Madeira; Descrições anatômicas; Informações fenológicas

Conhecendo espécies de plantas da Amazônia: morototó (Schefflera morototoni (Aubl.) Maguire, Steyerm. & Frodin - Araliaceae).

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