Compósito para a construção civil a partir de resíduos industriais

RESUMO Os estudos que visam à utilização dos resíduos industriais vêm se intensificando diante da pressão das organizações ambientais, escassez de recursos naturais, busca de certificações para ganho de mercado e minimização de impacto ambiental. O presente trabalho desenvolveu um novo compósito a base de resíduos industriais como cinzas de madeira, lodo de estação de tratamento de água (ETA) e resíduos de produção de cal com propriedades mecânicas que atendem às exigências da ASSOCIAÇÃO BRASILEIRA DE NORMAS TÉCNICAS - NBR 15270-1/2005, NBR 15270-2/2005 e NBR 5739/2007, objetivando a sua utilização na construção civil sem o acréscimo de cimento Portland. As resistências à compressão variaram de 2,35 a 16,48 MPa. O índice de absorção de água das amostras testadas também atendeu às normas aplicadas, demonstrando que ao longo do tempo de cura houve diminuição da porosidade com possível hidratação da cal. Os resultados do ensaio de resistência à compressão apresentaram variações durante o tempo de cura que podem ser justificadas pela presença de material orgânico no lodo de ETA e pelo tamanho das partículas de cinza de madeira que durante a homogeneização não foram destruídas completamente. Apesar das variações observadas nos resultados, as resistências dos compósitos se enquadram na classificação para blocos cilíndricos de concreto e blocos cerâmicos para alvenaria

Selection Of Stabilizing Additive For Lipase Immobilization On Controlled Pore Silica By Factorial Design

Candida rugosa lipase was covalently immobilized on silanized controlled pore silica (CPS) previously activated with glutaraldehyde in the presence of several additives to improve the performance of the immobilized form in long-term operation. Proteins (albumin and lecithin) and organic molecules (β-cyclodextrin and polyethylene glycol [PEG]-1500) were added during the immobilization procedure, and their effects are reported and compared to the behavior of the immobilized biocatalyst in the absence (lacking) of additive. The selection of the most efficient additive at different lipase loadings (150-450 U/g of dry support) was performed by experimental design. Two 22 full factorial designs with two repetitions at the center point were employed to evaluate the immobilization yield. A better stabilizing effect was found when small amounts of albumin or PEG-1500 were added simultaneously to the lipase onto the support. The catalytic activity had a maximum (193 U/mg) for lipase loading of 150 U/g of dry support using PEG-1500 as the stabilizing additive. This immobilized system was used to perform esterification reactions under repeated batch cycles (for the synthesis of butyl butyrate as a model). The half-life of the lipase immobilized on CPS in the presence of PEG-1500 was found to increase fivefold compared with the control (immobilized lipase on CPS without additive).91-93703718Faber, K., (1997) Biotransformation in Organic Chemistry: A Textbook, 3rd Ed., , Springer-Verlag, BerlinYahya, A.R.M., Anderson, W.A., Moo-Young, M., (1998) Enzyme Microb. Technol., 23, pp. 438-450Reslow, M., Adlercreutz, P., Mattiason, B., (1988) Eur. J. Biochem., 172, pp. 573-578Balcão, V.M., Paiva, A.L., Malcata, F.X., (1996) Enzyme Microb. Technol., 18, pp. 392-416Bosley, J.A., Peilow, A.D., (1997) J. Am. Oil Chem. Soc., 74, pp. 107-111Soares, C.M.F., De Castro, H.F., De Moraes, F.F., Zanin, G.M., (1999) Appl. Biochem. Biotechnol., 77-79, pp. 745-758Reetz, M.T., Zonta, A., Simpelkamp, J., (1996) Biotechnol. Bioeng., 49, pp. 527-534Wehtje, E., Adlercreutz, P., Mattiasson, B., (1993) Biotechnol. Bioeng., 41, pp. 171-178Rocha, J.M.S., Gil, M.H., Garcia, F.A.P., (1998) J. Biotechnol., 66, pp. 61-67Triantafyllou, A.O., Wehtje, E., Adlercreutz, P., Mattiasson, B., (1995) Biotechnol. Bioeng., 45, pp. 406-414Triantafyllou, A.O., Wehtje, E., Adlercreutz, P., Mattiasson, B., (1997) Biotechnol. Bioeng., 54, pp. 67-76Box, G.E.P., Hunter, W.G., Hunter, J.S., (1978) Statistics for Experimenters: An Introduction to Design, Data Analysis and Model Building, , Wiley & Sons, New YorkSzejtli, J., (1988) Cyclodextrin Technology, , Kluwer Academic, BostonBradford, M.M.A., (1976) Anal. Biochem., 72, pp. 248-254De Castro, H.F., Anderson, W.A., Legge, R.L., Moo-Young, M., (1992) Indian J. Chem., 31, pp. 891-89

Oleochemistry potential from Brazil northeastern exotic plants

International audienc

Production of low-calorie structured lipids from spent coffee grounds or olive pomace crude oils catalyzed by immobilized lipase in magnetic nanoparticles

In this study, crude oils extracted from spent coffee grounds (SCG) and olive pomace (OP) were used as raw-material to synthesize low-calorie triacylglycerols, either by acidolysis with capric acid, or by interesterification with ethyl caprate, in solvent-free media, catalyzed by sn-1,3 regioselective lipases. The Rhizopus oryzae lipase (ROL) was immobilized in magnetite nanoparticles (MNP\u2013ROL) and tested as novel biocatalyst. MNP-ROL performance was compared with that of the commercial immobilized Thermomyces lanuginosus lipase (Lipozyme TL IM). For both oils, Lipozyme TL IM preferred interesterification over acidolysis. MNP-ROL catalyzed reactions were faster and acidolysis was preferred with yields of c.a. 50% new triacylglycerols after 3 h acidolysis of OP or SCG oils. MNP-ROL was very stable following the Sadana deactivation model with half-lives of 163 h and 220 h when reused in batch acidolysis and interesterification of OP oil, respectively

Integrated Bioprocess for Structured Lipids, Emulsifiers and Biodiesel Production using Crude Acidic Olive Pomace Oils

Olive pomace oil (OPO), a by-product of olive oil industry, is directly consumed after refining. The novelty of this study consists of the direct use of crude high acidic OPO (3.4–20% acidity) to produce added-value compounds, using sn-1,3-regioselective lipases: (i) low-calorie dietetic structured lipids (SL) containing caprylic (C8:0) or capric (C10:0) acids by acidolysis or interesterification with their ethyl esters, (ii) fatty acid methyl esters (FAME) for biodiesel, and (iii) sn-2 monoacylglycerols (emulsifiers), as by-product of FAME production by methanolysis. Immobilized Rhizomucor miehei lipase showed similar activity in acidolysis and interesterification for SL production (yields: 47.8–53.4%, 7 h, 50℃) and was not affected by OPO acidity. Batch operational stability decreased with OPO acidity, but it was at least three-fold in interesterification that in acidolysis. Complete conversion of OPO into FAME and sn-2 monoacylglycerols was observed after 3 h-transesterification (glycerol stepwise addition) and lipase deactivation was negligeable after 11 cyclesinfo:eu-repo/semantics/publishedVersio

Revestimento ativo de amido na conservação pós-colheita de pera Williams minimamente processada Starch-based edible coating on extending shelf life of fresh-cut pear

A pera é uma das frutas de clima temperado mais consumidas no Brasil, no entanto sua conservação é limitada devido ao seu escurecimento quando sofre danos ou tratamentos físicos. Os revestimentos comestíveis interagem favoravelmente com o alimento, aumentando sua vida de prateleira. Este trabalho objetivou avaliar a ação de revestimento de amido adicionado de lactato de cálcio e L-cisteína na inibição do escurecimento enzimático, na redução do crescimento de psicrotrófilos e enterobactérias e na manutenção da textura. As peras fatiadas foram cobertas com revestimentos comestíveis à base de amido incorporados com cisteína e lactato de cálcio, exceto o controle - sem revestimento (C). Os tratamentos foram: apenas revestimento (T1); 2,0% lactato de cálcio e 1,0% L-cisteína (T2) e 2,0% lactato de cálcio e 1,5% L-cisteína (T3). As amostragens foram feitas nos tempos zero, dois, quatro e seis dias. As amostras foram mantidas sob refrigeração (7&deg;C&plusmn;2&deg;C). As peras submetidas aos tratamentos T2 e T3 apresentaram-se significativamente mais firmes (P<0,05) que as dos tratamentos C e T1. A ação da cisteína sobre a inibição do escurecimento enzimático foi observada nos tratamentos T2 e T3, que não apresentaram diferença significativa (P&#8805;0,05) entre si para os valores de &#8710;E, no entanto esses valores foram significativamente menores em relação ao controle. No tempo 6, a redução decimal na contagem de psicrotrófilos chegou a 3,03 e 2,43 para T3 e T2, em comparação com o controle. A contagem de enterobactérias apresentou comportamento semelhante, sendo o valor da redução de 3,16 e 3,05 para T2 e T3 em relação ao controle. Verificou-se que a vida de prateleira de pera minimamente processada pode ser mantida por mais tempo com o uso desse revestimento.<br>Pear is one of the most consumed temperate fruits in Brazil; however their conservation is limited due to browning when it suffers injuries or physical treatments. The edibles coating interact with the food positively extending its shelf life. This research aimed to evaluate the action of starch edible coating incorporated with calcium lactate and L-cysteine on enzymatic browning inhibition, on psychrotrophs and enterobacteriaceae growing reduction and on firmness maintenance. The sliced pears were coated with starch edible coating incorporated with L-cysteine and calcium lactate, except control, without coating (C). The treatment were: only coating (T1); 2,0% calcium lactate and 1,0% L-cysteine (T2); 2,0% calcium lactate and 1,5% L-cysteine (T3). The samples were taken at 0, 2, 4 and 6 days. Pears were keeped under refrigeration (7&deg;C&plusmn;2&deg;C). Pears submitted to treatments T2 and T3 show significantly more firms (P<0,05) compared to treatments C and T1. Cysteine action over enzymatic browning inhibition was observed in treatments T2 and T3 which do not differed significantly each other (P&#8805;0,05) to &#8710;E values however these were significantly lower than control (C). At time 6, decimal reduction on psychrotrophs counting reached 3,03 and 2,43 to T3 e T2 compared to control. Enterobacteriaceae counting showed similar behavior where the reduction values were 3,16 and 3,05 to T2 e T3 compared to control. It was verified that using the studied edible coating on fresh cut pear can extend its shelf life