O foco deste estudo correspondeu a hidrólise enzimática da polpa celulósica de sisal previamente mercerizada (20g de polpa.L-1, solução aquosa de NaOH 20%) via agitação mecânica (50°C,3h, M-AgMec-50°) e ultrassom (25°C,1h) a 20% (M-US-20%) e 40% (M-US-40%) de amplitude. As polpas mercerizadas apresentaram as seguinte propriedades: M-AgMec-50° 97,4% de α-celulose, cristalinidade (Ic) de 68% e massa molar média viscosimétrica (MMvis) de 94618,0g.mol-1, M-US-20% 95% de α-celulose, Ic de 68% e MMvis de 87581,6g.mol-1, M-US-40% 91,2% de α-celulose, Ic de 66% e MMvis de 81786,9g.mol-1. As reações de hidrólise (48h) foram realizadas utilizando enzimas celulase comercial (Accellerase 1500) e enzimas obtidas a partir do crescimento do fungo Aspergillus sp. Alíquotas constituídas por polpas não reagidas e licor foram retiradas do meio durante a reação. As polpas não reagidas foram caracterizadas em relação a Ic, MMvis, comprimento e espessura e microscopia eletrônica de varredura (MEV). Os licores foram avaliados pelo método Miller (DNS) e cromatografia líquida de alta eficiência(CLAE). Na hidrólise da polpa celulósica de sisal M-AgMec-50°, variou-se a quantidade de enzimas utilizadas (0,5 (HE-SAG-0,5); 0,7 (HE-SAG-0,7) e 0,9 (HE-SAG-0,9) mL de complexo enzimático. g-1 polpa celulósica). O maior rendimento de glicose (98%), obtido via CLAE, correspondeu a HE-SAG-0,9, sendo esta proporção de enzimas utilizada para as reações usando as polpas M-US-20% (HE-SU20-0,9), M-US-40%(HE-SU40-0,9). Dentre todas as polpas consideradas, o melhor rendimento de glicose foi para HE-SAG-0,9 pois, a presença de maior quantidade de hemiceluloses nas polpas celulósicas tratadas via ultrassom (HE-SU20-0,9 HE-SU40-0,9) prejudicou o acesso das enzimas às cadeias de celulose. As análises das polpas não reagidas mostraram que as enzimas celulases no geral agiram primeiramente na região não cristalina. Comportamentos variados foram observados com relação a Ic e MMvis, dependendo do intervalo de tempo transcorrido durante a reação. Considerando o pico de maior densidade de comprimento para as fibras de HE-SAG-0,5; HE-SAG-0,7 e HE-SAG-0,9, a variação durante a reação foi de [129-215] μm para [77-129] μm. As fibras de comprimentos superiores a [359-599] μm passaram a ser menores, aumentando a concentração de fibras com comprimentos menor que 359μm no meio. Para HE-SAG-0,5; HE-SAG-0,7; HE-SAG-0,9 o pico de maior densidade para a espessura variou de [28-39] para [11-23] μm, e para HE-SU20-0,9 e HE-SU40-0,9 este variou de [18-30] μm para [14-18] μm. O conjunto de resultados indicou que as enzimas agiram principalmente a partir das superfícies das fibras. As reações utilizando as enzimas celulases comercial e obtidas a partir do fungo Aspergillus foram realizadas utilizando outros substratos, além de M-AgMec-50° (HE-SAG-0,5; H-Aspergillus-SAG-1,5), ou seja, celulose microcristalina (HE-MICRO-0,5; H-Aspergillus-MICRO-1,5) e papel filtro (HE-PFT-0,5; H-Aspergillus-PFT-1,5). Dos três substratos utilizados, o papel filtro apresentou maior quantidade de hemiceluloses, e por isto, para as duas enzimas, observou-se para esta amostra o maior teor de açúcar redutor (DNS). A enzima fúngica, para todos os substratos, produziu um teor de açúcar muito menor que o obtido usando enzima comercial. As enzimas foram avaliadas via eletroforese de proteínas, sendo que para as enzimas fúngicas, foram observadas bandas de endoglucanases e exoglucanases, confirmando que durante o crescimento do fungo houve a formação das enzimas celulases. No entanto, as respectivas bandas das celulases comerciais mostraram que estas enzimas estão presentes em concentração consideravelmente maior, comparativamente as obtidas a partir do fungo Aspergillus sp. Ao comparar os resultados de Ic, MMvis, comprimento e espessura para todas as polpas não reagidas, usando as enzimas comercial e fúngica, observou-se que as enzimas fúngicas, nas condições consideradas no presente estudo atuaram de forma significativamente menos intensa que a comercial. Os estudos envolvendo as enzimas fúngicas requisitam aprofundamento. Dentre os resultados obtidos, destaca-se a alta conversão a glicose da polpa celulósica M-AgMec-50°, o que indicou que a hidrólise enzimática de polpa celulósica de sisal, com características similares à esta, apresenta grande potencial para produção de açúcares via catálise enzimática, visando obtenção de etanol. / This study corresponds to the enzymatic hydrolysis of previously mercerized pulp sisal (20g polpa.L-1 aqueous 20% NaOH) via mechanical agitation (50° C, 3h, M-AgMec-50°) and ultrasound (25° C, 1h) at 20% (M-US-20%) and 40% (-M-US 40%) of amplitude. The mercerized pulp had the following properties: M-AgMec-50° 97.4% of α-cellulose, 68% of crystallinity (Ic) and average viscometric molecular weight (MMvis) of 94618,0g.mol-1, M-US-20% 95% of α-cellulose, 68% of Ic and MMvis of 87581,6 g.mol-1, M-US-40% 91.2% α-cellulose, 66% of Ic and 81786,9g .mol-1 of MMvis. The hydrolysis reactions (48 h) were performed using commercial enzymes cellulase (Accellerase 1500) and enzymes obtained from the growth of the fungus Aspergillus sp. Aliquots constituted of unreacted pulp and liquor were taken from the medium during the reaction. The unreacted pulps were characterized with respect to Ic, MMvis, length and thickness and scanning electron microscopy (SEM). The liquors were analyzed by high performance liquid chromatography (HPLC) and by the Miller method (DNS). In the hydrolysis of the cellulose pulp sisal M-AgMec -50°, the amount of enzymes used was varied (0.5 (HE- SAG-0.5), 0.7 (HE-SAG-0.7) and 0.9 (HE-SAG-0.9) mL enzyme complex.g-1 pulp). The highest yield of glucose (98%), obtained via HPLC, corresponded to HE-SAG-0.9. This proportion of enzymes was used for the reactions using the pulps M-US-20% (HE-SU20-0,9) and M-US-40% (HE-SU40-0,9). Among all the considered pulps, the best performance for glucose was HE-SAG-0.9 as the presence of greater amounts of hemicellulose in pulps treated via ultrasonic (HE-HE-SU 20-0,9 SU40-0,9 ) made it difficult for the enzymes to access the cellulose chains. The analysis of unreacted pulps showed that, in general, cellulase enzymes act primarily on the non-crystalline region. Different behaviors were observed with respect to Ic and MMvis, depending on the time interval elapsed during the reaction. Considering the peak density of greater length for the fibers HE-SAG-0.5; HE-SAG-0.7 and HE-SAG-0.9, the variation during the reaction was [129-215] μm for [77-129] μm. The fibers of lengths greater than [359-599] μm became smaller, thus increasing the concentration of fibers with lengths smaller than 359μm in the medium. For HE-SAG-0.5; HE-SAG-0.7; HE-SAG-0.9 the peak of greater density of thickness varied from [28-39] to [11-23] μm and, for HE-SU20-0,9 and HE-SU40-0,9 that varied from [18-30] μm to [14-18] μm. The set of results indicated that the enzymes acted primarily from the fiber surfaces. Reactions using commercial cellulases and enzymes obtained from Aspergillus sp fungus were performed using other substrates in addition to M-AgMec-50°(HE-SAG-0,5; H-Aspergillus-SAG-1,5), which were microcrystalline cellulose (HE-MICRO-0,5; H-Aspergillus-MICRO-1,5) and filter paper (HE-PFT-0.5, H-Aspergillus-PFT-1,5). Out of the three substrates used, the filter paper showed a higher amount of hemicellulose, and therefore the highest concentration of reducing sugars (DNS) was observed in this sample for the two enzymes. For all the substrates, the fungal enzyme produced a much lower level of sugar than that obtained by using commercial enzyme. The enzymes were evaluated by electrophoresis of proteins. The bands of endoglucanases and exoglucanases were observed in the fungal enzymes, confirming that during the growth of the fungus there was the formation of cellulase enzymes. However, the respective bands of commercial cellulases showed that these enzymes are present in considerably higher concentration when compared to those obtained from the fungus Aspergillus sp. When comparing the results of Ic, MMvis, length and thickness for all the unreacted pulps using commercial and fungal enzymes under the conditions considered in this study, it was observed that fungal enzymes acted significantly less intensely than the commercial ones. Studies involving fungal enzymes need deepening. Among the obtained results, there is a high conversion of the glucose pulp AgMec-M50°, which indicated that the enzymatic hydrolysis of cellulosic pulps with features similar to the pulp used in the present study, has great potential for the production of sugars via enzymatic catalysis aiming at the production of ethanol.

Como conseqüência do aumento da produção de cana nos últimos anos, ocorreu o aumento da quantidade de resíduos agroindustriais gerados a partir deste processo, sendo os principais a palha e o bagaço da cana-de-açúcar. O potencial de produção desses resíduos representa em média 14% da massa da cana processada. A celulose é o principal constituinte desses materiais e pode dar origem a outros materiais por meio de reações de derivatização. Entre os derivados de celulose mais importantes, estão os éteres e os ésteres de celulose. A celulose também pode ser fragmentada, a fim de se utilizar seu monômero formador, a glicose. O presente trabalho teve como objetivo extrair a celulose da palha e do bagaço de cana para utilizá-la na produção de dois derivados, o acetato de celulose e a carboximetilcelulose, além de fragmentá-la a glicose, visando a estudar a hidrólise enzimática necessária para produção de etanol celulósico. Para isso, foram testadas duas vias de obtenção da celulose, uma via denominada ácida e outra, denominada alcalina. Ao término de cada etapa das vias, os materiais produzidos foram caracterizados quimicamente com a finalidade de se elucidar o que acontecia em cada etapa. Ao final dos dois processos, o material obtido foi submetido às reações de acetilação e de carboximetilação. Os derivados de celulose foram caracterizados quanto aos seus graus de substituição e por FTIR. Com o acetato de celulose, foram produzidas membranas através de dois métodos distintos, a evaporação de solvente e a inversão de fases. Essas membranas foram caracterizadas fisicamente por MEV, DMA e teste de permeabilidade. Elas também foram testadas quanto à remoção de íons cobre em solução em estado estacionário. Todos os materiais obtidos nas duas vias testadas foram hidrolisados enzimaticamente utilizando-se as enzimas Celluclast 1.5L e ?-glicosidase. Em todas as vias estudadas e para os dois materiais analisados, foram obtidos como produtos finais, materiais com alto teor de celulose (em torno de 90%) e baixo de teor de lignina (menor que 4%), sendo a via alcalina considerada a de melhor desempenho, pois ocorreu menor perda de celulose nessa via do que na via ácida. Foram produzidos acetatos de celulose com grau de substituição 3, ou seja, triacetatos, ideais para a produção de membranas. Contudo, a presença da lignina, mesmo em pequena quantidade, não permitiu que fossem produzidas membranas com alta resistência mecânica. Em geral as membranas foram capazes de remover cerca de 15,0% dos íons cobres em uma solução aquosa. Dos dois métodos estudados, o de inversão de fases foi o que produziu as melhores membranas. Quanto à carboximetilcelulose, foram produzidas CMCs de diferentes características e mais uma vez a lignina interferiu no processo, quanto mais lignina possuía o material antes da produção de CMC, menor foi o grau de substituição obtido. Nas reações de hidrólise enzimática, quanto mais puro era o material em relação ao teor de celulose, maior foi a concentração de glicose no hidrolisado, sendo alcançadas concentrações em torno de 85,00%. / As a consequence of sugarcane increased production in recent years, there was an increased of residues generation from this process, being the straw and bagasse the main ones. The production potential of these wastes represents around 14% of the processed sugarcane mass. Cellulose is the main constituent of these materials and may give rise to other materials by derivatization reactions. Among the most important derivatives of cellulose, are ethers and esters of cellulose. Cellulose can also be fragmented in order to use its monomer, the glucose. The present work aims at extracting the cellulose from sugarcane straw and bagasse to use it in the production of two derivatives, cellulose acetate and carboxymethylcellulose and to fragment it into glucose for studying the enzymatic hydrolysis, which is a required step for ethanol cellulosic production. For this, it was tested two pathways of cellulose obtaining, the acid route and the alkaline route. At the end of each stage of the process, the materials were characterized chemically in order to elucidate what occurred in each step. After finishing both processes, the material was subjected to reactions of acetylation and carboxymethylation. The cellulose derivates were characterized physically for its degree of substitution and for FTIR. The cellulose acetate was utilized to produce membranes through two different methods, the solvent evaporation and the phase inversion. The membranes were characterized for MEV, DMA and permeability test. They were also tested for cooper ions removal. All materials produced at both pathways were hydrolyzed enzymatically for the enzymes Celluclast 1.5L and ?-glucosidase. In all cases, the final material presented high level of cellulose (about 90,0%) and low level of lignin (low than 4,0%). The alkaline route can be considered the one which achieved the best results, since it was in this pathway that the lowest cellulose lost occurred. The cellulose acetates presented a degree of substitution 3, in other words, they are triacetates, ideal for membrane production. Nevertheless, the presence of lignin, even in low amount, did not allow producing membranes with high mechanic resistance. In general, the membranes were able to remove about 15,0% of cooper ions in a aqueous solution. Between the methods carried out, the phase inversion was the one which produced membranes with the best properties. In relation to carboxymethylcellulose, it was obtained CMCs with different characteristics and, once more, the lignin interfered in the process. The more lignin content before CMC production, the less degree of substitution obtained. In the reactions of enzymatic hydrolysis, the highest cellulose purity proportioned the highest glucose concentrations in the hidrolysates, and it was reached conversion values around 85,00%.

Oxidation plays an important role in the basic processes of life, such as the production of energy and phagocytosis employed by the immune system. However, when an imbalance between oxidants and antioxidants exists in vivo, oxidation can become uncontrolled and result in diseases such as arthritis, cancer, artherosclerosis, and Alzheimer’s Disease. Dietary antioxidants including polyphenolic compounds, proteins, and peptides have been identified as being physiologically functional foods capable of contributing to the restoration of this oxidant-antioxidant balance. The objective of this study was to explore the production of antioxidant soy peptides from a commercially available soy protein isolate (SPI) by enzymatic hydrolysis in a process similar to that occurring in the human digestive tract. In this study Archer-Daniels Midland SPI PRO-FAM 974 was used as a raw material for the production of antioxidant soy peptides. The digestion consisted of enzymatic digestion of the SPI (3.12 wt %) with pepsin (37ºC, pH 1.5) and/or pancreatin (40ºC, pH 7.8) either individually or sequentially. The enzyme concentration and digestion time for each enzyme was optimized using a 2^4 factorial experimental design to produce the greatest concentration of peptides quantified in PheGly equivalents by the OPA assay. A maximum peptide concentration of approximately 65 mM PheGly equivalents was achieved in the follow-up digests resulting from this factorial design model, using pepsin (0.15 g/L, 15 minutes) and pancreatin (4.5 g/L, 120 minutes) sequentially to digest the SPI. Fractionation of the peptides by sequential dead-end membrane ultrafiltration with molecular weight cut-offs (MWCO) of 3 kDa and 1 kDa was performed to produce peptide fractions with increased antioxidant capacity. The permeate flux as a function of time was fit to empirical models, revealing that the membrane fouling resulting in the permeate flux decline is largely reversible and most likely the result of cake filtration. Antioxidant capacity was quantified by the DPPH, FCR, and ORAC assays to determine the electron-donating and proton-donating capacities of the soy peptides. The electron-donating DPPH assay was not suitable to quantify the antioxidant capacity of the soy peptides due to poor peptide solubility in the assay media and sensitivity. The electron-donating FCR assay and the proton-donating ORAC assay were used to distinguish between the ultrafiltration and digestion conditions employed to produce the soy peptides and the antioxidant capacity was quantified in equivalence to the standard antioxidant Trolox. The soy peptide fraction with the greatest antioxidant capacity was produced by enzymatic digestion with pancreatin (4.5 g/L, 120 minutes) alone and had a molecular weight cut-off of between 3 kDa and 1 kDa. This fraction had an equivalent antioxidant capacity of approximately 190 mg Trolox/g sample in the ORAC assay and approximately 180 mg Trolox/g sample in the FCR assay. A preliminary linear model for the optimum digestion and ultrafiltration conditions for the production of antioxidant peptides with the greatest ORAC antioxidant capacity was also developed. The model includes a positive pancreatin digestion time term and a negative pepsin digestion time term. No ultrafiltration terms were found to be significant in this preliminary model, but a large constant term persisted. In conclusion, the enzymatic digestion of commercially available SPI with pancreatin and fractionated by ultrafiltration successfully produced a soy peptide fraction with increased antioxidant capacity.

The potential of high digestible grain sorghum (HDGS) with a modified starch protein endosperm matrix to replace corn in ethanol production was investigated using dry grind simultaneous saccharification and fermentation (SSF). Preliminary experiments showed that HDGS yielded higher amounts of glucose and ethanol than normal digestible grain sorghum (NDGS) and corn particularly in the first 48 hrs of fermentation. It was hypothesized that fast conversion of starch to glucose and ethanol during hydrolysis and fermentation are results of improved protein digestibility of HDGS. The invagination of protein structures in HDGS produced a flourier endosperm texture, softer kernels and lower starch content than the normal digestible protein (ND) lines. Highly digestible protein (HD) lines have better pasting properties (significantly lower pasting temperature, faster rate of gelatinization and higher peak viscosity) than ND lines based on the RVA profile. Increasing protein digestibility of the HDGS improved starch digestibility (increased rate of glucose conversion and total glucose yield during saccharification), which is supported by highly significant correlation of turbidity with rate of glucose conversion and efficiency of enzymatic conversion. The efficiency of ethanol conversion is significantly correlated with starch digestibility, pasting properties, and protein digestibility. Results also showed that HD sorghum lines had significantly faster rate of conversion and shorter reaction time needed to achieve completion than ND sorghum lines and corn. Increasing the dry solid concentration from 22% to 30% (w/v) increased the ethanol yield from 8% v/v to 13%v/v. This will allow considerable saving of water, reduced distillation cost and increased ethanol production for a given plant capacity and labor cost. Fineness of grind influences the amount of sugar formed due to variation in surface area of the flour. The hypothesis that finer particles has faster and higher glucose yield, defined as g of glucose converted per g of theoretical glucose, is supported by highly significant correlation of mass fraction of 3 to 60 mu m size range and mass median diameter (MMD) of 60 to 1000 mu m size range with glucose conversion efficiency and glucose conversion rate during saccharification and fermentation.

Energy utilization is a determining factor for the standards of living around the world, and the current primary source of energy is fossil fuels. A potential source of liquid fuels that could ease the strain caused by diminishing petroleum resources is bioethanol. Effective exploitation of biomass materials requires a pretreatment to disrupt the lignin and cellulose matrix. The pretreatment utilized for this research was oxygen delignification, which is a standard process stage in the production of bleached chemical pulp. The model substrate utilized as a feedstock for bioethanol was recovered fibre. An analysis of the substrates digestibility resulted in a hexose yield of approximately 23%, which justified the need for an effective pretreatment. An experimental design was performed to optimize the delignification conditions by performing experiments over a range of temperature, caustic loadings, and reaction times. Equations were developed that outline the dependence of various response parameters on the experimental variables. An empirical model that can predict sugar concentrations from enzymatic hydrolysis based on the Kappa number, enzyme loading, and initial fibre concentration was also developed. A study of hydrolysis feeding regimes for untreated recovered fibre (87 Kappa), pretreated recovered fibre (17 Kappa), and bleached pulp (6 Kappa) showed that the batch feeding regime offers reduced complexity and high sugar yields for lower Kappa substrates. In order to evaluate the possibility of lignin recovery, the pH of delignification liquor was reduced by the addition of CO₂ and H₂SO₄, resulting in up to 25% lignin yield. An experiment that looked at effect of post-delignification fibre washing on downstream hydrolysis found that a washing efficiency of approximately 90% is required in order to achieve a hexose sugar yield of 85%.

Oxidation plays an important role in the basic processes of life, such as the production of energy and phagocytosis employed by the immune system. However, when an imbalance between oxidants and antioxidants exists in vivo, oxidation can become uncontrolled and result in diseases such as arthritis, cancer, artherosclerosis, and Alzheimer’s Disease. Dietary antioxidants including polyphenolic compounds, proteins, and peptides have been identified as being physiologically functional foods capable of contributing to the restoration of this oxidant-antioxidant balance. The objective of this study was to explore the production of antioxidant soy peptides from a commercially available soy protein isolate (SPI) by enzymatic hydrolysis in a process similar to that occurring in the human digestive tract. In this study Archer-Daniels Midland SPI PRO-FAM 974 was used as a raw material for the production of antioxidant soy peptides. The digestion consisted of enzymatic digestion of the SPI (3.12 wt %) with pepsin (37ºC, pH 1.5) and/or pancreatin (40ºC, pH 7.8) either individually or sequentially. The enzyme concentration and digestion time for each enzyme was optimized using a 2^4 factorial experimental design to produce the greatest concentration of peptides quantified in PheGly equivalents by the OPA assay. A maximum peptide concentration of approximately 65 mM PheGly equivalents was achieved in the follow-up digests resulting from this factorial design model, using pepsin (0.15 g/L, 15 minutes) and pancreatin (4.5 g/L, 120 minutes) sequentially to digest the SPI. Fractionation of the peptides by sequential dead-end membrane ultrafiltration with molecular weight cut-offs (MWCO) of 3 kDa and 1 kDa was performed to produce peptide fractions with increased antioxidant capacity. The permeate flux as a function of time was fit to empirical models, revealing that the membrane fouling resulting in the permeate flux decline is largely reversible and most likely the result of cake filtration. Antioxidant capacity was quantified by the DPPH, FCR, and ORAC assays to determine the electron-donating and proton-donating capacities of the soy peptides. The electron-donating DPPH assay was not suitable to quantify the antioxidant capacity of the soy peptides due to poor peptide solubility in the assay media and sensitivity. The electron-donating FCR assay and the proton-donating ORAC assay were used to distinguish between the ultrafiltration and digestion conditions employed to produce the soy peptides and the antioxidant capacity was quantified in equivalence to the standard antioxidant Trolox. The soy peptide fraction with the greatest antioxidant capacity was produced by enzymatic digestion with pancreatin (4.5 g/L, 120 minutes) alone and had a molecular weight cut-off of between 3 kDa and 1 kDa. This fraction had an equivalent antioxidant capacity of approximately 190 mg Trolox/g sample in the ORAC assay and approximately 180 mg Trolox/g sample in the FCR assay. A preliminary linear model for the optimum digestion and ultrafiltration conditions for the production of antioxidant peptides with the greatest ORAC antioxidant capacity was also developed. The model includes a positive pancreatin digestion time term and a negative pepsin digestion time term. No ultrafiltration terms were found to be significant in this preliminary model, but a large constant term persisted. In conclusion, the enzymatic digestion of commercially available SPI with pancreatin and fractionated by ultrafiltration successfully produced a soy peptide fraction with increased antioxidant capacity.

Soybean production and consumption has increased in recent decades. However, trypsin inhibitor activity and “beany” flavour are two drawbacks limiting the utilization of soybean. In the present study, micronization, ethanol washing, and enzymatic hydrolysis (alone or in combination) were used to treat soybean. Micronization at 100 °C and 135 °C decreased the activity of both trypsin inhibitors (53% and 80% respectively), and lipoxygenase (51% and 99%, respectively). Ethanol increased the trypsin inhibitor activity while alcalase hydrolysis decreased its activity. Different treatment combinations affected trypsin inhibitor activity, with micronization having a major influence. “Beany” flavour related volatiles (hexanal, (E)- 2-hexenal, 1-hexanol, heptanal, (E)-2-octenal, (E)-2-nonenal, (E,E)-2,4-nonadienal, 2,4-decadienal, (E,E)-2,4-decadienal, 1-octen-3-ol, 2-pentylfuran and 3-octen-2-one) were significantly decreased with micronization. Ethanol effects varied with different volatiles. Soybean micronized at 135°C and washed with 65% ethanol was recommended for soybean processing due to its low trypsin inhibitor activity and low “beany” related volatile content.

Pseudo-lignin, which can be broadly defined as aromatic material that yields a positive acid-insoluble (Klason) lignin value, has been reported to generate from biomass polysaccharides during dilute acid pretreatment (DAP). To investigate the fundamental chemistry of pseudo-lignin, a series of state-to-art analytical techniques including GPC, FT-IR and ¹³C NMR were applied to characterize pseudo-lignin extracted from poplar α-cellulose and holocellulose after DAP. The results showed that pseudo-lignin is polymeric (Mn ~ 1000 g/mol; Mw ~ 5000 g/mol) and consists of carbonyl, carboxylic, aromatic, methoxy and aliphatic structures, which can be produced from both dilute acid-treated cellulose and hemicellulose. During DAP, the hydrolysis of polysaccharides, which leads to some release of monosaccharides, and their subsequent dehydration reactions to form furfural and 5-hydromethylfurfural (HMF) takes place. Further rearrangements of furfural and/or HMF can produce aromatic compounds, which undergo further polymerization and/or polycondensation reactions to form pseudo-lignin. More importantly, pseudo-lignin was revealed to bind with cellulase enzymes unproductively and significantly retard enzymatic conversion of cellulose. As compared to native lignin after DAP, the inhibition effect arise from pseudo-lignin is much stronger, which clearly indicates pseudo-lignin formation should be avoided during DAP. Process optimization study indicated that addition of dimethyl sulfoxide (DMSO) to the DAP reaction medium can effectively increase sugar recovery and reduce pseudo-lignin formation, even under high-severity pretreatment conditions. The pseudo-lignin suppression property of DMSO has been attributed to the preferential arrangement of DMSO in the vicinity of the C1 carbon of the HMF molecule, thereby protecting HMF from further reactions to form pseudo-lignin.

Energy utilization is a determining factor for the standards of living around the world, and the current primary source of energy is fossil fuels. A potential source of liquid fuels that could ease the strain caused by diminishing petroleum resources is bioethanol. Effective exploitation of biomass materials requires a pretreatment to disrupt the lignin and cellulose matrix. The pretreatment utilized for this research was oxygen delignification, which is a standard process stage in the production of bleached chemical pulp. The model substrate utilized as a feedstock for bioethanol was recovered fibre. An analysis of the substrates digestibility resulted in a hexose yield of approximately 23%, which justified the need for an effective pretreatment. An experimental design was performed to optimize the delignification conditions by performing experiments over a range of temperature, caustic loadings, and reaction times. Equations were developed that outline the dependence of various response parameters on the experimental variables. An empirical model that can predict sugar concentrations from enzymatic hydrolysis based on the Kappa number, enzyme loading, and initial fibre concentration was also developed. A study of hydrolysis feeding regimes for untreated recovered fibre (87 Kappa), pretreated recovered fibre (17 Kappa), and bleached pulp (6 Kappa) showed that the batch feeding regime offers reduced complexity and high sugar yields for lower Kappa substrates. In order to evaluate the possibility of lignin recovery, the pH of delignification liquor was reduced by the addition of CO₂ and H₂SO₄, resulting in up to 25% lignin yield. An experiment that looked at effect of post-delignification fibre washing on downstream hydrolysis found that a washing efficiency of approximately 90% is required in order to achieve a hexose sugar yield of 85%.

Submitted by Lucienne Costa (lucienneferreira@ufcg.edu.br) on 2018-03-23T20:07:03Z No. of bitstreams: 1 MARCIO JOSÉ VASCONCELOS DA SILVA – TESE (PPGEP) 2017.pdf: 2886790 bytes, checksum: 4e2912ac8b6df6d1df2aeb12d63b2646 (MD5) / Made available in DSpace on 2018-03-23T20:07:03Z (GMT). No. of bitstreams: 1 MARCIO JOSÉ VASCONCELOS DA SILVA – TESE (PPGEP) 2017.pdf: 2886790 bytes, checksum: 4e2912ac8b6df6d1df2aeb12d63b2646 (MD5) Previous issue date: 2017-12-05 / Na busca por fontes de energia renováveis e alternativas que reduzam a emissão de gases nocivos ao meio ambiente, diminuindo assim o uso de combustíveis fósseis em face da conscientização global, os biocombustíveis são uma fonte alternativa de energia, sendo principal destaque o etanol de 1ª e 2ª geração. Objetivou-se neste trabalho avaliar o potencial de diferentes cultivares de sorgo doce (Sorghum bicolor (L.) Moench.) para produção de etanol de 1ª geração a partir da fermentação do caldo dos colmos e etanol de 2ª geração a partir do substrato (bagaço). Para obtenção dos açúcares fermentescíveis a partir do bagaço, utilizou-se pré-tratamento ácido seguido de básico com auxílio de uma matriz de planejamento experimental 2³+3 pontos centrais para avaliar os efeitos das variáveis de entrada, tempo, temperatura e concentrações de ácido e base, verificando a solubilização da hemicelulose e lignina. Para avaliar a hidrólise enzimática verificou-se, por meio da aplicação de uma matriz de planejamento experimental 2²+3 pontos centrais, o efeito da carga enzimática e a razão massa seca de bagaço de sorgo e extrato enzimático. Foram usadas as enzimas comerciais Celluclast 1.5L da Novozyme e betaglicosidase da Prozyn na hidrólise enzimática para obtenção de açúcares fermentescíveis. A pesquisa foi desenvolvida no laboratório de engenharia bioquímica – LEB, na Universidade Federal de Campina Grande – UFCG, no estado da Paráiba e no Instituto Agronômico de Pernambuco – IPA, ambas localizadas na região do nordeste Brasileiro, a colheita das progens foi realizada na Estação Experimental do IPA no município de Vitória de Santo Antão, localizado na Zona da Mata de Pernambuco (lat: 35° 22' W, long: 08° 08' S, altitude: 146 m) no período de março/2013 a setembro/2017. Os resultados referentes aos dados agronômicos apresentaram diferenças significativas para um intervalo de confiança de 95% pelo teste Tukey. Dentre as sete cultivares pesquisadas as que obtiveram maiores teores de sólidos solúveis totais em campo foram entre BRS506, IPA2502, IPA EP17, IPA P222, IPA P134, IPA P228 e IPA SF15 com valores entre 12,3±0,08; 5,1±0,10; 16,8±0,40; 14,8±0,11; 7,1±0,10; 9,2±0,10 e 13,6±0,27 ºBrix, respectivamente. Os resultados referentes a fração sacarina (caldo do sorgo sacarino) foram analisados usando o teste de Tukey para um intervalo de confiança de 95%. Nos dados encontrados para concentração de etanol de 1ª geração, obtidos na fermentação dos caldos das cultivares que se destacaram foram IPA SF15, BRS506, IPA EP17, IPA P222 e IPA P134 com valores entre 55,72 ± 0,24; 45,46 ± 1,5; 44,6 ± 0,18; 33,78 ± 0,57 e 31,78 ± 0,28 g.L-1 respectivamente. As frações (bagaço) para avaliação na produção de etanol de 2ª geração, as cultivares IPA EP17 e BRS506, após pré-tratamento ácido seguido de básico, mostraram-se eficientes em concentrar a celulose, pela solubilização da hemicelulose e lignina, acarretando um aumento da celulose de 31,70 ± 0,49 para 60,42 ± 0,91% na variedade IPA-EP17 e para variedade BRS506 de 40,6 ± 1,1 para 64,52 ± 0,82% respectivamente. Os resultados encontrados no processo de hidrólise enzimática dos bagaços das variedades IPA EP17 para produção de glicose foi de 26,23 g L-1, nas condições de carga enzimática e razão (relação massa seca de bagaço) por volume de meio reacional (25 FPU/g e 2%) no tempo de 36 h de hidrólise e rotação constante de 150 RPM, e para BRS506 a produção de glicose foi de 25,17 g L-1, nas condições de carga enzimática e razão (relação massa seca de bagaço) por volume de meio reacional (25 FPU/g e 2%) no tempo de 36 h de hidrólise. / In the search for renewable energy sources and alternatives that reduce the emission of harmful gases to the environment, thus reducing the use of fossil fuels in the face of global awareness, biofuels present as an alternative, the main highlight being ethanol. The objective of this work was to evaluate the potential of different cultivars of sweet sorghum (Sorghum bicolor (L.) Moench.) For the production of ethanol of 1st generation from the fermentation of the broth the 2st generation ethanol from the substrate (bagasse). To obtain the fermentable sugars from the bagasse, acid pretreatment followed by base with the aid of experimental planning 2³ + 3 central points was applied to evaluate the effects of the variables of entry, time, temperature and acid and base concentrations, verifying the solubilization of hemicellulose and lignin. In order to evaluate the enzymatic hydrolysis, the effect of the enzymatic loading and the dry mass ratio of sorghum bagasse and enzyme extract wereverified using experimental planning design 2² + 3 central points. The commercial enzymes Celluclast 1.5L from Novozyme and beta-glucosidase from Prozyn wereused in the enzymatic hydrolysis to obtain fermentable sugars. The research was carried out at the biochemical-engineering laboratory - LEB, at the Federal University of Campina Grande - UFCG, in the state of Paráiba and at the Agronomic Institute of Pernambuco - IPA, both located in the northeast region of Brazil. The progenies were collected at the IPA Experimental Station in the city of Vitória de Santo Antão, located in the Zona da Mata of Pernambuco (lat: 35 ° 22 'W, long: 08 ° 08' S, altitude: 146 m) from March / 2013 to September / 2017. The results concerning agronomic data presented significant differences for a 95% confidence interval by the Tukey test. Among the seven cultivars studied, the highest soluble solids in the field were BRS506, IPA2502, IPA EP17, IPA P222, IPA P134, IPA P228 and IPA SF15 with values between 12,3 ± 0,08; 5,1 ± 0,10; 16,8 ± 0,40; 14,8 ± 0,11; 7,1 ± 0,10; 9,2 ± 0,10 and 13,6 ± 0,27 °Brix, respectively. Results for saccharin fraction (sorghum broth) were analyzed using the Tukey's test for a 95% confidence interval. In the data obtained for the concentration of ethanol of 1st generation, obtained in the fermentation of the broths of the cultivars that stood out were IPA SF15, BRS506, IPA EP17, IPA P222 and IPA P134 with values between 55,72 ± 0,24; 45,46 ± 1,5; 44,6 ± 0,18; 33,78 ± 0,57 and 31,78 ± 0,28 g.L-1 respectively. The fractions (bagasse) for evaluation in the production of second generation ethanol, IPA EP17 and BRS506, after acid pretreatment followed by basic, were efficient in concentrating the cellulose by the solubilization of hemicellulose and lignin, resulting in an increase of cellulose from 31,70 ± 0,49 to 60,42 ± 0,91% in the variety IPA-EP17 and for the BRS506 variety from 40,6 ± 1,1 to 64,52 ± 0,82% respectively. The results obtained in the enzymatic hydrolysis process for the IPA EP17 variety in the glucose production were 26,23 g L-1, for enzyme loading conditions and ratio (bagasse dry mass ratio) per reaction medium volume (25 FPU / and 2%) in the time of 36 hours of hydrolysis and constant rotation of 150 RPM, for BRS506 variety the glucose production was 25,17 g.L-1, for the conditions of enzymatic loading and ratio (bagasse dry mass ratio) by volume of reaction medium (25 FPU / g and 2%) in the time of 36 hours of hydrolysis.