Hydrodynamic cavitation-assisted acid pretreatment and fed-batch simultaneous saccharification and co-fermentation for ethanol production from sugarcane bagasse using immobilized cells of Scheffersomyces parashehatae.

A new alternative for hydrodynamic cavitation-assisted pretreatment of sugarcane bagasse was proposed, along with a simultaneous saccharification and co-fermentation (SSCF) process performed in interconnected columns. Influential variables in the pretreatment were evaluated using a statistical design, indicating that an ozone flow rate of 10 mg min-1 and a pH of 5.10 resulted in 86 % and 72 % glucan and xylan hydrolysis yields, respectively, in the subsequent enzymatic hydrolysis process. Under these optimized conditions, iron sulfate (15 mg L-1) was added to assess Fenton pretreatment, resulting in glucan and xylan hydrolysis yields of 92 % and 71 %, respectively, in a material pretreated for 10 min. In SSCF, ethanol volumetric productivities of 0.33 g L-1 h-1 and of 0.54 g L-1 h-1 were obtained in batch and fed-batch operation modes, achieving 26 g L-1 of ethanol in 48 h in the latter mode.

A review on recent developments in hydrodynamic cavitation and advanced oxidative processes for pretreatment of lignocellulosic materials.

Environmental problems due to utilization of fossil-derived materials for energy and chemical generation has prompted the use of renewable alternative sources, such as lignocellulose biomass (LB). Indeed, the production of biomolecules and biofuels from LB is among the most important current research topics aiming to development a sustainable bioeconomy. Yet, the industrial use of LB is limited by the recalcitrance of biomass, which impairs the hydrolysis of the carbohydrate fractions. Hydrodynamic cavitation (HC) and Advanced Oxidative Processes (AOPs) has been proposed as innovative pretreatment strategies aiming to reduce process time and chemical inputs. Therefore, the underlying mechanisms, procedural strategies, influence on biomass structure, and research gaps were critically discussed in this review. The performed discussion can contribute to future developments, giving a wide overview of the main involved aspects.

Composição centesimal e mineral de plantas medicinais comercializadas no mercado do Porto de Cuiabá, Mato Grosso, Brasil / Centesimal and mineral composition of medicinal plants commercialized in the Cuiabá Port Market, Mato Grosso, Brazil

RESUMO O presente trabalho teve como objetivo determinar a composição centesimal (cinzas, umidade, proteínas, lipídeos e carboidratos totais) e mineral (Na, K, Ca, Cu, Fe, Mg, Mn e Zn) das plantas medicinais Barbatimão (Stryphnodendron adstringens (Mart.) Coville), Carqueja (Baccharis trimera (Less) D.C.), Mangava-Brava (Lafoensia pacari A. St.-Hil.), e Quebra Pedra (Phyllanthus niruri L.) comercializadas no mercado do Porto de Cuiabá, MT. As amostras foram identificadas botanicamente por meio da exsicata feita no Instituto de Botânica da Universidade Federal de Mato Grosso, Campus Cuiabá. A composição centesimal foi determinada de acordo com as recomendações da Association of Official Analytical Chemists e a concentração dos minerais foi quantificada por Espectrometria de Absorção Atômica em Chama. Os resultados obtidos foram: umidade (7,72% a 12,10%); cinzas (1,64% a 8,44%); proteínas (2,36% a 9,35%); lipídeos (0,41% a 2,05%); carboidratos totais (72,09% a 82,37%) e, foram encontradas diferenças significativas entre as amostras (p < 0,05). As concentrações dos minerais nas amostras variaram de 0,01 a 21,57 mg/g nas plantas secas e 0,01 a 32,17 mg/200mL das infusões. Os resultados médios obtidos indicam que, exceto para o K, Ca e Mn todas as amostras não apresentaram diferenças significativas (p ≥ 0,05) nas concentrações de minerais. A capacidade de extração dos minerais da matéria seca para a infusão obedeceu à seguinte ordem: Na>K>Zn>Cu>Mg>Mn>Ca>Fe. Os valores obtidos em 200 mL das infusões quando comparados aos índices diários recomendados para minerais sugerem que os chás avaliados podem ser fonte de minerais, principalmente de K e Mn.

ABSTRACT The purpose of this study was to determine the proximal (ash, moisture, protein, lipids, and total carbohydrates) and mineral (Na, K, Ca, Cu, Fe, Mg, Mn, and Zn) composition of the medicinal plants barbatimão (Stryphnodendron adstringens (Mart.) Coville), carqueja (Baccharis trimera (Less) D.C.), mangava-brava (Lafoensia pacari A. St.-Hil.), pau-tenente (Quassia amara L.), and quebra pedra (Phyllanthus niruri L.), commercialized in the Cuiabá Port Market in Mato Grosso. The samples were botanically identified by the voucher specimen grown in the Botanical Institute of the Federal University of Mato Grosso, at the Cuiabá campus. Proximal composition was determined according to the recommendations of the Association of Official Analytical Chemists and the concentration of minerals was quantified by flame atomic absorption spectrometry. The results obtained were: moisture content (7.72% to 12.10%); ashes (1.64% to 8.44%); protein (2.36% to 9.35%); lipids (0.41% to 2.05%), and total carbohydrates (72.09% to 82.37%), and significant differences were found between the samples (p≥0.05). The mineral concentrations varied from 0.01 to 21.57 mg/g in the plants and 0.01 to 32.17 mg/200mL in the infusions. No significant differences (p≥0.05) were found between the samples for mineral composition, except for K, Ca, and Mg. The mineral extraction capacity of the dry matter for infusions was as follows: Na>K>Zn>Cu>Mg>Mn>Ca>Fe. The daily index values of the metal species quantified in 200 mL infusions suggest that teas can be a source of minerals, especially K and Mn.