Emprego de Spray Dryer na indústria de alimentos: uma breve revisão

A secagem é um processo importante e amplamente empregado para a conservação de diversos tipos de alimentos. Quando realizado com o auxílio de elevadas temperaturas e tempos de secagem, pode ocasionar danos nos constituintes dos alimentos, como a degradação de componentes bioativos. O spray dryer é uma das técnicas de secagem que se destacam na indústria alimentícia, por ser um processo rápido, contínuo, econômico e por não expor o produto a elevadas temperaturas, diminuindo desta forma a sua degradação e perdas nutricionais. As propriedades do produto formado no processo dependem de uma série de variáveis que devem ser controladas, como a propriedades do líquido de alimentação, o design do equipamento e os parâmetros do processo. Neste sentido, este presente trabalho objetivou-se na revisão bibliográfica de aspectos importantes presentes no uso do processo de secagem por spray dryer na indústria alimentícia

Emprego de Spray Dryer na indústria de alimentos: uma breve revisão

A secagem é um processo importante e amplamente empregado para a conservação de diversos tipos de alimentos. Quando realizado com o auxílio de elevadas temperaturas e tempos de secagem, pode ocasionar danos nos constituintes dos alimentos, como a degradação de componentes bioativos. O spray dryer é uma das técnicas de secagem que se destacam na indústria alimentícia, por ser um processo rápido, contínuo, econômico e por não expor o produto a elevadas temperaturas, diminuindo desta forma a sua degradação e perdas nutricionais. As propriedades do produto formado no processo dependem de uma série de variáveis que devem ser controladas, como a propriedades do líquido de alimentação, o design do equipamento e os parâmetros do processo. Neste sentido, este presente trabalho objetivou-se na revisão bibliográfica de aspectos importantes presentes no uso do processo de secagem por spray dryer na indústria alimentícia

Ensemble inequivalence in random graphs

We present a complete analytical solution of a system of Potts spins on a random k-regular graph in both the canonical and microcanonical ensembles, using the Large Deviation Cavity Method (LDCM). The solution is shown to be composed of three different branches, resulting in an non-concave entropy function.The analytical solution is confirmed with numerical Metropolis and Creutz simulations and our results clearly demonstrate the presence of a region with negative specific heat and, consequently, ensemble inequivalence between the canonical and microcanonical ensembles.Comment: 9 pages, 3 figure

Atmospheric observation-based global SF6 emissions - comparison of top-down and bottom-up estimates

Emissions of sulphur hexafluoride (SF6), one of the strongest greenhouse gases on a per molecule basis, are targeted to be collectively reduced under the Kyoto Protocol. Because of its long atmospheric lifetime (≈3000 years), the accumulation of SF6 in the atmosphere is a direct measure of its global emissions. Examination of our extended data set of globally distributed high-precision SF6 observations shows an increase in SF6 abundance from near zero in the 1970s to a global mean of 6.7 ppt by the end of 2008. In-depth evaluation of our long-term data records shows that the global source of SF6 decreased after 1995, most likely due to SF6 emission reductions in industrialised countries, but increased again after 1998. By subtracting those emissions reported by Annex I countries to the United Nations Framework Convention of Climatic Change (UNFCCC) from our observation-inferred SF6 source leaves a surprisingly large gap of more than 70–80% of non-reported SF6 emissions in the last decade

Contrasting physical and chemical conditions of two rock glacier springs

9openInternationalBothRock glaciers are increasingly influencing the hydrology and water chemistry of Alpine catchments. During three consecutive summers (2017–2019), we monitored by recording probes and fortnightly/monthly field campaigns the physical and chemical conditions of two rock glacier springs (ZRG, SRG) in the Zay and Solda/Sulden catchments (Eastern Italian Alps). The springs have contrasting hydrological conditions with ZRG emerging with evident ponding (pond-like), and SRG being a typical high-elevation seep (stream-like). Water temperature was constantly low (mean 1.2°C, standard deviation 0.1°C) at both springs. Concentrations of major ions (dominated by SO42−, HCO3−, Ca2+ and Mg2+) and trace elements (As, Sr, Ba, U, Rb) increased, and water became more enriched in heavy stable isotopes (δ18O, δ2H) towards autumn. This solute and isotopic enrichment had an asymptotic trend at SRG, and a unimodal pattern at ZRG, where peaks occurred 60–80 days after the snowmelt end. Wavelet analysis of electrical conductivity (EC) and water temperature records revealed daily cycles only at SRG, and significant weekly/biweekly fluctuations at both springs attributable to oscillations of meteorological conditions. Several rainfall events triggered a transient (0.5–2 h) EC drop (of 5–240 μS cm−1) and water temperature rise (of 0.2–1.4°C) at SRG (dilution and warming), whereas only intense rainfall events occasionally increased EC (by 15–85 μS cm−1) at ZRG (solute enrichment and thermal buffering), with a long-lasting effect (6–48 h). Building on previous research, we suggest that rock glacier springs with differing flow conditions, that is, stream-like and pond-like, have contrasting fluctuations of water parameters at different timescales. Thus, for pond-like springs, peaks of EC/solute concentrations might indicate a seasonal window of major permafrost thaw. Our quantitative description of the hydrochemical seasonality in rock glacier outflows and the physical and chemical response to precipitation events provides relevant information for water management in mountain areas under climate change.openBrighenti, Stefano; Engel, Michael; Tolotti, Monica; Bruno, Maria Cristina; Wharton, Geraldene; Comiti, Francesco; Tirler, Werner; Cerasino, Leonardo; Bertoldi, WalterBrighenti, S.; Engel, M.; Tolotti, M.; Bruno, M.C.; Wharton, G.; Comiti, F.; Tirler, W.; Cerasino, L.; Bertoldi, W

Osteointegration of porous absorbable bone substitutes: A systematic review of the literature

Biomaterials’ structural characteristics and the addition of osteoinductors influence the osteointegration capacity of bone substitutes. This study aims to identify the characteristics of porous and resorbable bone substitutes that influence new bone formation. An Internet search for studies reporting new bone formation rates in bone defects filled with porous and resorbable substitutes was performed in duplicate using the PubMed, Web of Science, Scielo, and University of São Paulo Digital Library databases. Metaphyseal or calvarial bone defects 4 to 10 mm in diameter from various animal models were selected. New bone formation rates were collected from the histomorphometry or micro-CT data. The following variables were analyzed: animal model, bone region, defect diameter, follow-up time after implantation, basic substitute material, osteoinductor addition, pore size and porosity. Of 3,266 initially identified articles, 15 articles describing 32 experimental groups met the inclusion criteria. There were no differences between the groups in the experimental model characteristics, except for the follow-up time, which showed a very weak to moderate correlation with the rate of new bone formation. In terms of the biomaterial and structural characteristics, only porosity showed a significant influence on the rate of new bone formation. Higher porosity is related to higher new bone formation rates. The influence of other characteristics could not be identified, possibly due to the large variety of experimental models and methodologies used to estimate new bone formation rates. We suggest the inclusion of standard control groups in future experimental studies to compare biomaterials

Priorities for Africa's food and nutrition security post-covid-19. A contribution from the Task Force Rural Africa (TFRA) to the AU-EU Summit, October 2020

A deep sense of concern about the impact of the COVID-19 pandemic on the lives and livelihoods of Africa’s people has inspired the writing of this contribution. As members of the Task Force Rural Africa (TFRA), we produced a report in March 2019 on what we thought was needed to transform Africa’s agriculture and rural economy. Less than one year later, COVID-19 struck Africa and the rest of the world with devastating effect. Another important change since March 2019 has been the shift on climate policy, represented by the EU Commission proposal in December 2019 of the European Green Deal (EGD). This ambitious vision, aimed at making Europe the first climate-neutral continent by 2050, will have implications for Africa – Europe relations. The combination of COVID-19’s impact on Africa and the EU’s climate policy change has led us to re-examine the analysis and the recommendations in our original report. We have drawn one central conclusion from our work: that food and nutrition security has become of such fundamental political, economic and social importance that it must be at the centre of all future policy and planning. We have built our report on this conclusion and produced a set of short and long-term recommendations we believe are relevant to the new world shaped by the COVID-19 pandemic. We hope our contribution may help in the preparation of the AU-EU Summit in October 2020. The Summit will seek to agree the long-term basis for partnership between Africa and the EU. It will meet at a crucially important time, shortly before the US Presidential election, when the world will be looking to see how Africa and Europe, separately and in partnership, can contribute to an effective multilateral response to global challenges and the current COVID-19 crisis. We wish the leaders well in their efforts

Evaluation of microbiological contamination of amniotic membrane and amniotic fluid

PURPOSE: To verify and compare the possible microbiological contamination of amniotic fluid, and amniotic membranes at time zero and at different times after delivery. METHODS: Nine amniotic fluid samples were collected by intrauterine aspiration and nine amniotic membranes were collected after cesarean deliveries of patients with negative serology (HIV, syphilis, hepatitis B and C). Samples were collected at different times after delivery (zero, thirty, sixty minutes). The samples were inoculated in culture media for bacteria and fungi. RESULTS: Bacteria were retrieved from four amniotic fluid samples, as well as from all nine amniotic membranes. Coagulase-negative Staphylococcus was the most prevalent bacteria. At time zero, coagulase-negative Staphylococcus was revealed in all nine amniotic membranes, Staphylococcus aureus in two, Neisseria sp., Enterobacter and Streptococcus viridans in one. Thirty minutes after delivery, coagulase negative Staphylococcus grew in all nine amniotic membranes and Streptococcus viridans in one. Sixty minutes after delivery, coagulase-negative Staphylococcus was shown in eight, Staphylococcus aureus in two and Streptococcus viridans in one sample. Coagulase-negative Staphylococcus was found in three amniotic fluids and corresponding membranes. CONCLUSION: Amniotic membrane contamination was a problem in all samples, and the processing protocol used at the Federal University of São Paulo was efficient to decontaminate the AM. Care must be taken before the use of AM. Further studies are necessary to establish the accurate variation of AM contamination at different times after delivery.OBJETIVOS: Verificar a possibilidade de contaminação do líquido amniótico e da membrana amniótica no tempo zero e em diferentes tempos após o parto. MÉTODO: Nove amostras de líquido amniótico foram colhidas através de punção uterina. Nove membranas amnióticas foram obtidas de placentas após cesáreas eletivas em gestantes com sorologias negativas (hepatite B, C, sífilis, HIV). Obtiveram-se amostras de membranas amnióticas em três diferentes momentos após o parto (zero, trinta e sessenta minutos). As amostras de membrana foram inoculadas em meios para cultivo bacteriano e fúngico. RESULTADOS: Verificou-se cultivo positivo para bactérias em quatro amostras do líquido amniótico e em todas membranas amnióticas. Staphylococcus coagulase negativo cresceu nas nove membranas estudadas. No tempo zero houve crescimento de Staphylococcus coagulase negativo em todas as membranas, de Staphylococcus aureus em duas, de Enterobacter, Neisseria sp. e Streptococcus viridans em uma cada. No tempo trinta, o Staphylococcus coagulase negativo também cresceu em todas as membranas e o Streptococus viridans em uma. No tempo sessenta, o Staphylococcus coagulase negativo cresceu em oito das nove membranas, o Staphylococcus aureus em duas e o Streptococus viridans em uma. Staphylococcus coagulase negativo foi encontrado em três amostras de líquido e membranas amnióticas correspondentes. CONCLUSÃO: Contaminação bacteriana foi evidenciada em todas as membranas amnióticas. Cuidados assépticos devem ser realizados durante todo o manuseio da membrana antes de sua utilização. Estudos quantitativos com maior número de amostras são necessários para comparação mais acurada da variação da contaminação da membrana amniótica em diferentes tempos após a sua retirada.Universidade Federal de São Paulo (UNIFESP) Departamento de OftalmologiaUniversidade Federal de São Paulo (UNIFESP) Departamento de Oftalmologia Setor de Doenças Externas Oculares e CórneaUNIFESP, Depto. de OftalmologiaUNIFESP, Depto. de Oftalmologia Setor de Doenças Externas Oculares e CórneaSciEL