Metal reduction in wine using PVI-PVP copolymer and its effects on chemical and sensory characters

We studied the influence of an adsorbent PVI-PVP resin (a copolymer of vinylimidazole and vinylpyrrolidone), on the removal of heavy metals in wines, mainly copper (Cu), iron (Fe), lead (Pb), cadmium (Cd) and aluminium (Al). The study also investigated the influence of PVI-PVP on the physical-chemical and sensory characteristics of white and red wines, comparing its effect when applied in the must and in the wine. The removal of metals was more effective when PVI-PVP was applied to the wine than to the must. The removal of Fe and Pb was more effective in white wines than in red wines, while the removal of Cu and Al was higher in red wines. In general, the higher the PVI-PVP dose, the greater the quantity of metallic elements (copper, iron, lead and aluminium) that are removed. PVI-PVP had a minor effect on phenolic composition. The wines showed some decrease in total acidity and an increase in pH with PVI-PVP. The application of PVI-PVP at the dose rates employed here did not affect the wine’s sensory characteristics significantly

Organosolv delignification of steam exploded wheat straw

Atualmente tem-se aumentado o interesse no estudo de processos alternativos depolpação que conciliam um alto desempenho e causando pouco impacto ambiental. Da mesmamaneira, o uso de resíduos agrícolas é cada vez mais citado como matéria-prima promissorapara produção de produtos químicos. A palha de trigo é um resíduo agrícola muito abundantee foi usado em muitos países para a produção de polpas de celulose. Este trabalho descreveo efeito do pré-tratamento através de uma explosão a vapor seguido de uma polpação comacetona/água na palha de trigo. As amostras de palha de trigo foram tratadas através de explosão a vapor com temperaturas variando entre 190 e 210 oC durante 4 min e em seguidasubmetidas ao tratamento com acetona/água (1:1/v:v) a diferentes temperaturas (140, 160e 200oC) durante um tempo de 60 min de polpação. O pré-tratamento por explosão a vaporlevou a um aumento da quantidade de lignina extraída pela polpação organossolve. Esteefeito foi mais pronunciado para as polpações realizadas a menores temperaturas. O uso detemperaturas mais elevadas no tratamento por explosão a vapor foi mais signi…cativo, poisresultou em menores valores de rendimento de polpa e maiores taxas de deslignificação

Influence of halloysite nanotubes on physical and mechanical properties of cellulose fibres reinforced vinyl ester composites

Natural fibres are generally added to polymer matrix composites to produce materials with the desirable mechanical properties of higher specific strength and higher specific modulus while at the same time to maintain a low density and low cost. The physical and mechanical properties of polymer composites can be enhanced through the addition of nanofillers such as halloysite nanotubes. This article describes the fabrication of vinyl ester eco-composites and eco-nanocomposites and characterizes these samples in terms of water absorption, mechanical and thermal properties. Weight gain test and Fourier transform infrared analysis indicated that 5% halloysite nanotube addition gave favourable reduction in the water absorption and increased the fibre–matrix adhesion leading to improved strength properties in the eco-nanocomposites. However, halloysite nanotube addition resulted in reduced toughness but improved thermal stability

State of the art of the meiofauna of Brazilian Sandy Beaches

Abstract In Brazil, meiofauna studies began in the middle of last century, but they adopted a purely taxonomical approach, describing species from various zoological groups. After this first step, this benthic group was largely neglected until the end of the 20th century when ecological studies began. We here provide a brief review of present knowledge of the meiofauna found on Brazilian sandy beaches to provide information for ReBentos (Coastal Benthic Habitats Monitoring Network). Our methodology consisted of a bibliographic survey undertaken using different datasets (Web of ScienceTM, SCOPUS, Google Scholar and Lattes Plataform). For the survey, we considered only those studies published till early 2015. Our analysis showed that the number of meiofauna studies has increased over the last two decades, though they are mainly still concentrated on the Southeast of Brazil. These studies aim to explain the distribution pattern of the meiofauna of the intertidal region of sandy beaches. Based on the results, we presented a discussion of three main topics, i.e., (a) current knowledge of Brazilian sandy beach meiofauna, (b) sampling strategies for monitoring of the meiofauna, and (c) use of the meiofauna as a tool to assess climate change. We trust that this brief review will be useful as a starting point for the delineation of further climate change investigations into sandy beach meiofauna