Luiza Helena da Silva Martins

Effects of the pretreatment method on high solids enzymatic hydrolysis and ethanol fermentation of the cellulosic fraction of sugarcane bagasse.

This work evaluated ethanol production from sugarcane bagasse at high solids loadings in the pretreatment (20-40% w/v) and hydrolysis (10-20% w/v) stages. The best conditions for diluted sulfuric acid, AHP and Ox-B pretreatments were determined and mass balances including pretreatment, hydrolysis and fermentation were calculated. From a technical point of view, the best pretreatment was AHP, which enabled the production of glucose concentrations near 8% with high productivity (3.27 g/Lh), as well as ethanol production from 100.9 to 135.4 kg ethanol/ton raw bagasse. However, reagent consumption for acid pretreatment was much lower. Furthermore, for processes that use pentoses and hexoses separately, this pretreatment produces the most desirable pentoses liquor, with higher xylose concentration in the monomeric form.

Purification of Lactic Acid Produced by Fermentation: Focus on Non-traditional Distillation Processes

Lactic acid is commonly used in a wide range of fields such as cosmetics, pharmaceutical products, chemistry and food. During the last years, its use for new applications such as production of biodegradable and biocompatible polymers, green solvents and oxygenated chemicals have received considerable attention. However, the relatively high production cost of lactic acid hinders many large-scale applications. In order to cheapen lactic acid production processes, it is necessary to develop more efficient methods of separation and purification. This work reviews some promising non-traditional distillation processes that are currently employed for lactic acid recovery, focusing on reactive distillation and molecular distillation. Advances in such distillation-based processes, their drawbacks and concluding remarks are also presented.

CARACTERIZAÇÃO FÍSICA, FÍSICO-QUÍMICA E POTENCIAL TECNOLÓGICO DE FRUTOS DE CAMAPÚ (Physalis angulata L.)

O objetivo deste estudo foi investigar o potencial tecnologico de frutos de camapu. Para isso foram determinadas as caracteristicas fisicas, fisico-quimicas e os teores de vitamina C, carotenoides totais, compostos fenolicos totais e a capacidade de sequestrar radicais livres atraves do metodo DPPH (2,2-difenil-1-picril hidrazil). Alguns dos resultados observados foram: solidos soluveis de 12°Brix; pH de 4,11; Aw de 0,97; teor de proteinas de 0,95% ; 6,45% de acucares totais e 4,12% of acucares redutores; 25 mg.100g -1 de vitamina C; 3,99 μg.g -1 de carotenoides totais; 61,70 mg GAE. 100g -1 para compostos fenolicos totais e a capacidade antioxidante de IC 50 : 93,01 e 92,8 μ g .mL -1 para extracao aquosa e metanolica respectivamente . Os resultados obtidos mostraram teores consideraveis de fenolicos totais e atividade antioxidante mediana para os frutos de camapu, comparaveis a outras frutas ja amplamente comercializadas no brasil. O objetivo deste estudo foi investigar o potencial tecnologico de frutos de camapu. Para isso foram determinadas as caracteristicas fisicas, fisico-quimicas e os teores de vitamina C, carotenoides totais, compostos fenolicos totais e a capacidade de sequestrar radicais livres atraves do metodo DPPH (2,2-difenil-1-picril hidrazil). Alguns dos resultados observados foram: solidos soluveis de 12°Brix; pH de 4,11; Aw de 0,97; teor de proteinas de 0,95% ; 6,45% de acucares totais e 4,12% de acucares redutores; 25 mg.100g-1 de vitamina C; 3,99 μg g-1 de carotenoides totais; 61,70 mg GAE. 100g-1 para compostos fenolicos totais e a capacidade antioxidante de IC50: 93,01 e 92,8 μg.mL-1 para extracao aquosa e metanolica respectivamente. Os resultados obtidos mostraram teores consideraveis de fenolicos totais e atividade antioxidante mediana para os frutos de camapu, comparaveis a outras frutas ja amplamente comercializadas no Brasil.

Nanotechnology Applications on Lignocellulosic Biomass Pretreatment

Global population growth raises questions concerning the environment and energy production. Fossil fuels are well known and utilized energy source. These are not renewable and contribute to the greenhouse gas effect. The search for alternative energy sources and solution for environmental problems has a growing concern in recent years. The lignocellulosic biomass has emerged as a solution to our energy and environmental concerns since it is rich within feedstock and can be converted to biofuels and/or biomaterials. This approach is interesting because these biomasses can become renewable sources of energy and pollute less than fossil fuels when transformed into biofuels, which is a green fuel. However, some steps are necessary to transform these lignocellulosic biomasses into biofuels or biomaterials. Nanotechnology is a multidisciplinary area of study with several applications that can be used to improve the lignocellulose bioconversion process, used both in production of liquid fuels through conversion by fermentation, gasification, or catalysis and development of new nanoscale catalyzers/materials. Nanoscale or sub-nanoscale instrumentation facilitates understanding of the lignocellulosic biomass cell wall ultrastructure and enzymatic mechanisms. This aspect contributes in the development of sophisticated instrumentation techniques for lignocellulosic fiber analysis such as scanning electronic microscopy (SEM), transmission electronic microscopy (TEM), and atomic force microscopy (AFM).