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

Continuous beer fermentation with yeast immobilized on alternative cheap carriers and sensorial evaluation of the final product

Continuous beer fermentation offers a wide range of advantages, mostly of economic nature over the traditional batch process. However, due to increased complexity of operation comparing to batch process, flavor problems, risk of contamination, yeast viability, carrier price and inconvenience of immobilization, the continuous beer fermentation has found few practical applications so far. The carrier cost represents a significant part of the investment costs and therefore the need for a cheap support material easy to regenerate is still relevant. This work deals with a complete continuous fermentation system for beer fermentation and maturation consisting of an airlift and a packed-bed reactor containing brewing yeast immobilized on spent grains and corncobs, respectively. The objective of this study was to verify the long-term performance of the system and the suitability of these new cellulose-based carrier materials made from brewing and agricultural by-products. Further the influence of feed rate and aeration rate on bioreactors fermentation performance, immobilized biomass load, ethanol production and flavor profile of both green and maturated beer was followed. The influence of process parameters on sensorial quality of beer has been studied by physicochemical methods as well as by sensorial analysis (acceptance and description tests) carried out by both consumers and experienced tasters. This work clearly demonstrated the technological feasibility of the continuous brewing based on yeast immobilization on cheap alternative carriers (spent grains, corncobs) for continuous production of a beer with a balanced flavor profile.Fundação para a Ciência e a Tecnologia (FCT) - SFRH / BPD / 3541 / 2000.Fundação de Amparo a Pesquisa do Estado de São Paulo (FAPESP) - Proc. 00/12767-4.Unicer SA.

Influence of different pre-treatment methods on the immobilization of brewer’s yeast on corn cob particles

Fundação para a Ciência e Tecnologia (FCT

Realistic fluids as source for dynamically accreting black holes in a cosmological background

We show that a single imperfect fluid can be used as a source to obtain the generalized McVittie metric as an exact solution to Einstein's equations. The mass parameter in this metric varies with time thanks to a mechanism based on the presence of a temperature gradient. This fully dynamical solution is interpreted as an accreting black hole in an expanding universe if the metric asymptotes to Schwarzschild-de Sitter at temporal infinity. We present a simple but instructive example for the mass function and briefly discuss the structure of the apparent horizons and the past singularity.Comment: 5 pages, 2 figures. Updated references and minor changes to match the version accepted for publishing in PR

High gravity batch and continuous processes for beer production: evaluation of fermentation performance and beer quality

This study deals with two innovative brewing processes, high gravity batch and complete continuous beer fermentation systems. The results show a significant influence of the variables such as concentration and temperature on the yield factor of the substrate into ethanol and consequently on the productivity of the high gravity batch process. The technological feasibility of continuous production of beer based on yeast immobilization on cheap alternative carriers was also demonstrated. The influence of process parameters on fermentation performance and quality of the obtained beers was studied by sensorial analysis. No significant difference in the degree of acceptance between the obtained products and some traditional market brands was found.FAPESP; CAPES; CNPq (Brazil); Malteria do Vale, Wallerstein Industrial e Commercial, Corn Products Brasil; Johnson-Diversey; FCT/Portugal; MŠMT Czech Republic; Unicer S.A

p-Sulfonic acid calixarenes as efficient and reusable organocatalysts for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones/-thiones

AbstractA new and efficient methodology is proposed for obtaining 3,4-dihydropyrimidin-2(1H)-ones/-thiones through Biginelli reactions. It is based on the use of less than the stoichiometric amount of p-sulfonic acid calixarenes as organocatalysts. A number of aromatic aldehydes as well as urea or thiourea can be employed for successfully synthesizing the corresponding Biginelli adducts. The described methodology is devoid of metal-containing catalysts, which in turn is very attractive for safely producing 3,4-dihydropyrimidin-2-(1H)-ones/-thiones of pharmacological interest. In addition, the catalyst efficiency is not compromised after its successive use in reactions. This is the first report about the application of calixarenes as catalysts in the multicomponent Biginelli reaction

Aqueous two-phase micellar systems in an oscillatory flow micro-reactor: Study of perspectives and experimental performance

Aqueous two-phase micellar systems (ATPMS) are micellar surfactant solutions with physical properties that make them very efficient for the extraction/concentration of biological products. In this work the main proposal that has been discussed is the possible applicability and importance of a novel oscillatory flow micro-reactor (micro-OFR) envisaged for parallel screening and/or development of industrial bioprocesses in ATPMS. Based on the technology of oscillatory flow mixing (OFM), this batch or continuous micro-reactor has been presented as a new small-scale alternative for biological or physical-chemical applications. RESULTS: ATPMS experiments were carried out in different OFM conditions (times, temperatures, oscillation frequencies and amplitudes) for the extraction of glucose-6-phosphate dehydrogenase (G6PD) in Triton X-114/buffer with Cibacron Blue as affinity ligand. CONCLUSION: The results suggest the potential use of OFR, considering this process a promising and new alternative for the purification or pre-concentration of bioproducts. Despite the applied homogenization and extraction conditions have presented no improvements in the partitioning selectivity of the target enzyme, when at rest temperature they have influenced the partitioning behavior in Triton X-114 ATPMS.The authors acknowledge the financial support from FCT (Fundacao para a Ciencia e Tecnologia/Portugal, SFRH/BPD/26108/2005), as well as from FAPESP (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo/Brasil), CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico/Brasil), and CAPES (Coordenacao para Aperfeicoamento do Ensino Superior/Brasil)

Design and Implementation of Flower Export Consortium in Ceará State, Brazil

 The Brazilian presence in international commerce, despite the regional leadership in Latin America and the global importance of Brazil as an emerging economy, is quite limited, reaching only 1% of the world’s total trade. Nevertheless, the agribusiness sector is responsible for half of the country’s export and Brazil is the world leader in sugar, coffee, orange juice, tobacco, soybean and beef export. Export growth is considered to be a key factor for the economic development of the country and many governmental programs are being carried out. The Ministry of Agriculture, Livestock and Food Supply (MAPA), through its Cooperative Department (DENACOOP), has joined these efforts. The DENACOOP export consortia program is focused on building strategic alliance in agribusiness production chain. After successful experiences in implementing in grain and honey sector, an applied research project was set up focusing on a flower production chain in Northeast of Brazil, which has the potential to improve socio-economic indicators of a low income region. To carry out the project the Federal University of Viçosa research team has developed a design and implemen-tation procedure, which was based on structuring and translating the requirements of organizations and producers into contract’s clause. The consortium main clauses established that all the purchase and sale of agricultural inputs, the internal and external seedling market, roses, ornamental and vase flowers will be done together. The commercialization and the post-harvest activities will be done through the creation of a distribution center. Recently flower producers have signed the export consortium contract. The consortium is expected to improve the competitiveness of the flower production chain in the state of Ceará and increase the current minor importance of Brazil in the international flower trade

Sensorial evaluation of continuously fermented beer and the role of process parameters in adjusting its flavour profile

Although traditional batch overwhelmingly prevails over continuous fermentation, a breakthrough in quality and savings could be achieved by a simple, flexible and cheap fermentation system. This work deals with a complete continuous beer fermentation consisting of an airlift and a packed-bed reactor containing yeast immobilized on spent grains and corncobs, respectively. The goal was to study the influence of process parameters on bioreactor performance and flavour profile of beer. Consumers considered the continuously fermented beer to be of a regular quality. The possibility of flavour adjustments by changing the process parameters was proved by a panel of experienced tasters.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BPD/3541/2000.MŠMT - MSM 6046137305, Czech Republic.Fundação de Amparo a Pesquisa do Estado de São Paulo (FAPESP).UNICER S.A