Determinação da 2,5-hexanodiona em amostras de urina submetidas à hidrólise ácida: importância da coluna cromatográfica e do pH do meio

Acidic hydrolysis of samples is frequent in urinary 2,5-hexanodione determination. This hydrolysis should be performed under proper conditions, in order to avoid interference, such as the presence of 2,5-dimethylfurane and 2-acetylfurane. The results of the present work, as well as data from the literature, show that the use of non-polar or slightly polar chromatographic columns of 30 m length is an essential condition for 2,5-HD determination in an acid hydrolysed urine sample. In the same way the pH should be kept between 0.3 and 0.5. The mean concentrations of 2,5-HD in samples submitted to hydrolysis (0.50 ± 0.28 mg/g of creatinine) was about 3 times higher than those found in the samples without acid hydrolysis (0.19 ± 0.3 mg/g of creatinine).

Purificação e caracterização de uma gentioexaose obtida de botriosferana por hidrólise ácida parcial

A hexa-oligosaccharide was obtained by partial acid hydrolysis from botryosphaeran, an exopolysaccharide (EPS) β(1→3; 1→6)-D-glucan type, produced by the ascomyceteous fungus Botryosphaeria rhodina. The oligosaccharide was purified by gel filtration and charcoal-Celite column chromatography and the analysis was followed by HPAEC/PAD. The structure was determined by NMR spectroscopy and mass spectrometry, which showed that the oligosaccharide consists of six β-D-glucopiranosyl units O-6 substituted (gentiohexaose).

Determinação de bifenilos policlorados em soro de cordão umbilical através de extração por hidrólise ácida seguida de cromatografia a gás acoplada a um microdetector de captura de elétrons

The present work describes the determination of polychlorinated biphenyls in 123 umbilical cord serum samples by liquid-liquid extraction method with acid hydrolyze step and analysis by GC-mECD. The analytical method was evaluated with following figures of merit for all PCBs: linearity (>0.997); precision (<12.55%); recoveries (73-119%); limit of detection (0.1 ng mL-1); limit of quantification (0.25-0.5 ng mL-1). The results showed high contamination in the analyzed samples. PCB more frequent was 138 (66.7%), followed by 180 (55.3%) and 52 (51.3%).

Purificação e caracterização de uma gentioexaose obtida de botriosferana por hidrólise ácida parcial

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sacarificação da polpa cítrica por hidrólise ácida e cultivo pelo processo de batelada simples com reciclo de Trichoderma reesei ou Aspergillus niger com produção de celulases e poligalacturonases

Pós-graduação em Microbiologia - IBILCE

Estudos da pré-hidrólise ácida do bagaço de cana-de-açúcar e fermentação alcóolica do mosto de xilose por Pachysolen tannophilus

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo das características estruturais de amidos: efeito do 'annealing', da hidrólise ácida e da hidrólise enzimática

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Obtenção dos parâmetros e estudo cinético da hidrólise ácida dos resíduos florestais de eucalipto

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação da Hidrólise Ácida e Alcalina do Caroço de Abacate para a Produção de Etanol

New patterns from replaceable sources have been searched by scientific community to ethanol produce. The seed of avocado has thereabout 20% of starch. The starch hydrolysis results fermentable sugars by Saccharomyces cerevisiae, and the ethanol is the major product of fermentation. The starch can be hydrolysed by acids, basis and enzymes. Previous studies showed that enzymatic hydrolysis can produce 26,01 liter of ethanol per ton of seed. At the present work, we analyzed the chemistry hydrolysis efficiency before the enzymatic hydrolysis and the use of dormant seed consequence. The Brix rate variation at each stage was evaluated and the ethanol concentration was determined with gas chromatograph technique. The chemistry hydrolysis with subsequent enzymatic hydrolysis was effective, producing until 61,8 L.ton-1. The use of dormant seeds wasn’t significative to raise the Brix rate. The seed of avocado demonstrated to be an alternative replaceable source to ethanol produce

Pré-hidrólise ácida de bagaço de cana-de-açúcar e sua caracterização físico-química

The biomass resulting from processing sugarcane bagasse has been considered a source of cellulose with the potential production of bio-fuels. This lignocellulose can be processed into ethanol since is hydrolyzed by chemical processes (acids) or biotechnology (enzymes) which generate sugars suit for fermentation. This study had the objective to utilize physical and chemical pre-treatment processes for prehydrolysis of sugarcane bagasse. The experimental treatment was adjusted at a factor of 4 X 2, by the combination of pre-hydrolysis timing (15, 30, 45 and 60 minutes) and sulfuric acid concentrations (7.0% and 9.0%) which was incubated at a temperature of 121° C in an autoclave. The treatment data was subjected to analysis of the variance and averages which were compared using the Tukey test with a probability of 5%. The results obtained showed that through pretreatment acid applied on the lignocellulose material, there was a significant break from the substrate fibers like cellulose, hemicellulose and lignin.

Alternativas de uso da borra de café através de hidrólise ácida, enzimática, ou como substrato para a produção das enzimas: lacase e celulase

In the industrial production of soluble coffee, huge amounts of extracted coffee residues are generated; onaverage, for eachtonne of green coffee extracted, 480 kg of coffee ground waste is produced. This is a solid residue currently used to generate energy at the steam boilers from the soluble coffee industry. Some is also used or as fertilizer on agriculture fields. Seeking a better end use, the work reported here aimed to study the viability of hydrolyzing the coffee ground residue for the production of carbohydrates. Hydrolysis was undertaken with hydrochloric acid at different temperatures and pressures, using a water bath or autoclave.An enzymatic hydrolysis with Viscozyme Lwas developed using Whatman filter paper No1 and the optimal conditions were determined using a rotational central composite experimental design (DCCR).The best conditions to hydrolyze filter paper cellulose were 50 FBG (Fungal β-glucanase) of Viscozyme L at pH 4.0 for 1.0 h and 45 ºC. The ground coffee was hydrolyzed under the same conditions as described above for filter paper, however this enzymatic hydrolysis was not efficient. A combination of enzymatic hydrolysis as a pre-treatment for the ground coffee followed by acid hydrolysis using HCl conducted in an autoclave (120 C for 2.0 h) resulted in higher production of glucose as analyzed by HPLC. Another end use of the ground coffee evaluated was as source of substrate in the culture medium to grow Botryosphaeria rhodina MAMB-05 to produce the enzymes laccase and cellulase. Highest enzyme titres obtained were with 8% (w/v) coffee grounds to which was added a minimum salts medium(Vogel), under agitation conditions (180 rpm) at 28ºC. The phenolic compounds present in the coffee grounds appear to have induced laccase by Botryosphaeria rhodina.

Efeito da hidrólise ácida dos taninos de Eucalyptus grandis w. hill ex Maiden nas propriedades dos adesivos tânicos

Este trabalho teve como objetivo avaliar o efeito da hidrólise ácida sobre as propriedades e resistência ao cisalhamento dos adesivos de taninos, extraídos a partir da casca de Eucalyptus grandis W. Hill ex Maiden. Os adesivos foram sintetizados com taninos hidrolisados, empregando-se quatro valores de pH, três tempos de reação e 10% de formaldeído em relação à massa seca de taninos. Foram produzidas 96 juntas coladas, constituídas de duas lâminas de madeira de Eucalyptus grandis. As resistências ao cisalhamento e falha na madeira foram determinadas de acordo com a norma ASTM D 2339-93. Concluiu-se que a hidrólise ácida dos taninos reduziu a viscosidade dos adesivos e aumentou a resistência ao cisalhamento na linha de cola. De modo geral, as juntas coladas apresentaram baixo percentual de falha na madeira.

Hidrólise ácida de bagaço de cana-de-açúcar para produção de etanol por fermentação pelo consórcio Zymomonas mobilis CCT4494 e Pachysolen tannophilus CCT1891

Pós-graduação em Engenharia e Ciência de Alimentos - IBILCE

Desenvolvimento de bionanocompósitos: nano e microcristais de celulose com poli (álcool vinílico) e poli (ácido lático)

This work has the main objective to obtain nano and microcrystals of cellulose, extracted from the pineapple leaf fibres (PALF), as reinforcement for the manufacture of biocomposite films with polymeric matrices of Poly(vinyl alcohol) (PVA) and Poly(lactic acid) (PLA). The polymer matrices and the nano and microcrystals of cellulose were characterised by means of TGA, FTIR and DSC. The analysis was performed on the pineapple leaves to identify the macro and micronutrients. The fibers of the leaves of the pineapple were extracted in a desfibradeira mechanical. The PALF extracted were washed to remove washable impurities and subsequently treated with sodium hydroxide (NaOH) and sodium hypochlorite (NaClO) in the removal of impurities, such as fat, grease, pectates, pectin and lignin. The processed PALF fibers were hydrolysed in sulfuric acid (H2SO4) at a concentration of 13.5 %, to obtain nano and microcrystals of cellulose. In the manufacture of biocomposite films, concentrations of cellulose, 0 %, 1 %, 3 %, 6 %, 9% and 12% were used as reinforcement to the matrices of PVA and PLA. The PVA was dissolved in distilled water at 80 ± 5 oC and the PLA was dissolved in dichloromethane at room temperature. The manufacture of biocompósitos in the form of films was carried out by "casting". Tests were carried out to study the water absorption by the films and mechanical test of resistance to traction according to ASTM D638-10 with a velocity of 50 mm/min.. Chi-square statistical test was used to check for the existence of significant differences in the level of 0.05: the lengths of the PALF, lengths of the nano and microcrystals of cellulose and the procedures used for the filtration using filter syringe of 0.2 μm or filtration and centrifugation. The hydrophilicity of biocompósitos was analysed by measuring the contact angle and the thickness of biocompósitos were compared as well as the results of tests of traction. Statistical T test - Student was also applied with the significance level (0.05). In biodegradation, Sturm test of standard D5209 was used. Nano and microcrystals of cellulose with lengths ranging from 7.33 nm to 186.17 nm were found. The PVA films showed average thicknesses of 0.153 μm and PLA 0.210 μm. There is a strong linear correlation directly proportional between the traction of the films of PVA and the concentration of cellulose in the films (composite) (0,7336), while the thickness of the film was correlated in 0.1404. Nano and microcrystals of cellulose and thickness together, correlated to 0.8740. While the correlation between the cellulose content and tensile strength was weak and inversely proportional (- 0,0057) and thickness in -0.2602, totaling -0,2659 in PLA films. This can be attributed to the nano and microcrystals of cellulose not fully adsorbed to the PLA matrix. In the comparison of the results of the traction of the two polymer matrices, the nano and microcrystals have helped in reducing the traction of the films (composite) of PLA. There was still the degradation of the film of PVA, within a period of 20 days, which was not seen in the PLA film, on the other hand, the observations made in the literature, the average time to start the degradation is above 60 days. What can be said that the films are biodegradable composites, with hydrophilicity and the nano and microcrystals of cellulose, contribute positively in the improvement of the results of polymer matrices used.

Desempenho e composição corporal de novilhas alimentadas com dois níveis de concentrado e bagaço de cana submetidos a diferentes processos de hidrólise

O objetivo deste trabalho foi testar duas formas de hidrólise do bagaço de cana (com [17kgf/cm²]e sem [4kgf/cm²] rápida descompressão pós-hidrólise) e dois níveis de concentrado (25 e 45% MS) no desempenho e na composição corporal de novilhas em crescimento sob regime confinado durante 112 dias. Vinte e quatro novilhas Nelore e 12 Canchim foram distribuídas em delineamento de blocos casualizados em arranjo fatorial 2x2. Os resultados demonstraram que a omissão da explosão pós-hidrólise e o uso de níveis mais elevados de concentrado aumentaram o ganho de peso e o consumo de alimentos. Os resultados para ganho de peso e consumo de matéria seca, respectivamente, para tratamento sem vs com descompressão e 45 vs 25% de concentrado, foram 0,76 vs 0,67 e 0,76 vs 0,66 kg/d e 6,7 vs 5,8 e 6,8 vs 5,7 kg/dia. Entretanto, não houve diferença entre os tratamentos para conversão alimentar. Não foram observadas diferenças entre os tratamentos quanto à composição corporal determinada por meio do espaço de deutério ao final do período de confinamento, embora a taxa estimada de deposição de lipídios tenha sido maior para o tratamento sem explosão (216 vs 175 g/d) e o tratamento com 45% de concentrado (225 vs 166 g/d). Não foram observadas vantagens na descompressão rápida pós-hidrólise em alta pressão na eficiência de conversão de alimentos. Os resultados demonstram que animais alimentados com bagaço hidrolisado em níveis altos de ingestão (2,9% PV) e proporções baixas de concentrado apresentaram eficiência de utilização da dieta semelhante a dietas com níveis mais altos de concentrado.