Influence Of The Degree Of Hydrolysis And Type Of Enzyme On Antioxidant Activity Of Okara Protein Hydrolysates

The objective of this work was to evaluate the antioxidant activity of protein hydrolysates obtained by the enzymatic hydrolysis of okara using an endopeptidase (Alcalase) and exopeptidase (Flavourzyme). The reaction was monitored by the pH-stat procedure in which five aliquots were collected during the hydrolysis by each enzyme, corresponding to different degrees of hydrolysis (DH). The antioxidant activities of the aliquots were evaluated by the ABTS, DPPH and FRAP methods. For the hydrolysates obtained using Alcalase, the antioxidant activities increased from: 68.6 to 99.5% (ABTS), 14.5 to 17.7% (DPPH) and 222.6 to 684.9 [iM Trolox (FRAP), when the DH varied from 0 to 33.6%. With respect to Flavourzyme, the results were: 67.2 to 88.2% (ABTS), 9.5 to 18.5% (DPPH) and 168.0 to 360.3 [µM Trolox (FRAP), when the DH increased up to 5.8%. The results showed that the protein hydrolysates had antioxidant capacities, which were influenced by the degree of hydrolysis and the type of enzyme. © 2016 Sociedade Brasileira de Ciencia e Tecnologia de Alimentos, SBCTA. All rights reserved.36237538

Empleo de carbones activados procedentes de lignina como catalizadores no metálicos en la oxidación húmeda con peróxido de hidrogeno

Una lignina obtenida por un proceso a la sosa se empleó como precursor para preparar carbones activados. En primer lugar, se carbonizó la lignina en atmósfera inerte y, a continuación, se procedió a su activación térmica en atmósfera oxidante usando temperaturas entre 150 y 350 C. Se emplearon distintas técnicas de caracterización para evaluar sus propiedades texturales y química superficial, observando un aumento del desarrollo de la porosidad con la temperatura de activación usada, y un marcado carácter básico en todos ellos. Los carbones preparados se ensayaron como catalizadores no metálicos para la oxidación húmeda catalítica con peróxido de hidrógeno (CWPO) de 4-nitrofenol (4-NP; 5 g L-1), usando condiciones de operación relativamente suaves (presión atmosférica, T = 50 C, pH = 3, carga de catalizador = 2.5 g L-1, [H2O2]0 = 17.8 g L-1). Con los catalizadores preparados a las temperaturas de activación más altas (300 y 350 C) se logró eliminar cerca del 70 % de 4-NP, observándose una eficiente descomposición de H2O2. Por su parte, los materiales preparados a las temperaturas de activación más bajas (150 y 200 C) promovieron una descomposición del H2O2 más rápida pero ineficiente, eliminándose menos del 25 % de 4-NP en estos casos.info:eu-repo/semantics/publishedVersio

Formate Over-Oxidation Limits Industrialization of Glycerol Oxidation Paired with Carbon Dioxide Reduction to Formate

Electrocatalytic CO2 reduction processes are generally coupled with the oxidation of water. Process economics can greatly improve by replacing the water oxidation with a more valuable oxidation reaction, a process called paired electrolysis. Here we report the feasibility of pairing CO2 reduction with the oxidation of glycerol on Ni3S2/NF anodes to produce formate at both anode and cathode. Initially we optimized the oxidation of glycerol to maximize the Faraday efficiency to formate by using design of experiments. In flow cell electrolysis, excellent selectivity (up to 90 % Faraday efficiency) was achieved at high current density (150 mA/cm2 of geometric surface area). Then we successfully paired the reduction of CO2 with the oxidation of glycerol. A prerequisite for industrial application is to obtain reaction mixtures with a high concentration of formate to enable efficient downstream separation. We show that the anodic process is limited in formate concentration, as Faraday efficiency to formate greatly decreases when operating at 2.5 M formate (∼10 w%) in the reaction mixture due to over-oxidation of formate. We identify this as a major bottleneck for the industrial feasibility of this paired electrolysis process.</p

A progressive refinement approach for the visualisation of implicit surfaces

Visualising implicit surfaces with the ray casting method is a slow procedure. The design cycle of a new implicit surface is, therefore, fraught with long latency times as a user must wait for the surface to be rendered before being able to decide what changes should be introduced in the next iteration. In this paper, we present an attempt at reducing the design cycle of an implicit surface modeler by introducing a progressive refinement rendering approach to the visualisation of implicit surfaces. This progressive refinement renderer provides a quick previewing facility. It first displays a low quality estimate of what the final rendering is going to be and, as the computation progresses, increases the quality of this estimate at a steady rate. The progressive refinement algorithm is based on the adaptive subdivision of the viewing frustrum into smaller cells. An estimate for the variation of the implicit function inside each cell is obtained with an affine arithmetic range estimation technique. Overall, we show that our progressive refinement approach not only provides the user with visual feedback as the rendering advances but is also capable of completing the image faster than a conventional implicit surface rendering algorithm based on ray casting

Life-cycle greenhouse gas emissions of portuguese olive oil

The main goal of this paper was to assess the greenhouse gas (GHG) intensity of olive oil production in Portugal. A life-cycle model and inventory were implemented for the entire production process, including a comprehensive analysis of olive cultivation, olive oil extraction, packaging, and distribution. Data originates from five differently-sized Portuguese olive growers and from a total of six olive oil mills, representing the three extraction processes in use: three-phase extraction, two-phase extraction, and traditional pressing. The results show that the GHG intensity lies in the range 1.8-8.2 kg CO2eq/liter and that the main contributors were fertilizers (production and field emissions). Efficient use of fertilizers thus seems to be a key factor for mitigating the GHG intensity of olive oil production.This research was supported by project ECODEEP (Eco-efficiency and Eco-management in the Agro Industrial sector, FCOMP–05–0128–FEDER–018643) and the Portuguese Scienc

Metal-free catalysts derived from lignin for efficient wet peroxide oxidation

In this work, a wheat and hemp lignin (Sarkanda, Granit S.A.) has been used as raw material for the development of metal-free activated carbons. These materials were tested in the catalytic wet peroxide oxidation (CWPO) of 4-nitrophenol (4-NP; 5 g L-1) during 24 h experiments conducted at relatively mild operating conditions (p = 1 atm, t = 50 °C, pH = 3, catalyst load = 2.5 g L-1 and [H2O2]0 = 17.8 g L-1). First, the lignin was carbonized under N2 atmosphere followed by the activation of the obtained non-porous carbon (LG) under air atmosphere at different temperatures (150 to 350 ºC), leading to the generation of significant porosity

Electrochemical CO2 reduction on gas diffusion electrodes: enhanced selectivity of In–Bi bimetallic particles and catalyst layer optimization through a design of experiment approach

CO2 electroreduction to formate powered by renewable energy is an attractive strategy to recycle carbon.Electrode materials showing high selectivity for formate at high current densities are post-transition metals such as Sn, In, Pb, Hg, and Bi. Scaling up the CO2 electroreduction technology to industrial size will require, among other things, maximization of selectivity at high current densities. We show here that InBielectrocatalysts provide enhanced selectivity compared to pure In and Bi and that a proper formulation of the catalyst layer can have a profound impact on the performance of gas diffusion electrode electrolyzers. The best performing electrodes screened in this study show nearly 100% current efficiency at current densities up to 400 mA cm−2 for 2 h. Additionally, one electrode was shown to operate at a current density of 200 mA cm−2 for 48 h at a current efficiency of 85% and remained operating with a current efficiency above 50% for 124 h.Catalysis and Surface Chemistr

Existence of continuous eigenvalues for a class of parametric problems involving the (p,2)-laplacian operator

We discuss a parametric eigenvalue problem, where the differential operator is of (p,2)-Laplacian type. We show that, when p≠2, the spectrum of the operator is a half line, with the end point formulated in terms of the parameter and the principal eigenvalue of the Laplacian with zero Dirichlet boundary conditions. Two cases are considered corresponding to p>2 and p2, and to infinity in the case of p<2

Clinical and epidemiological characteristics of patients from Ribeirão Preto, SP, Brazil, with AIDS and oportunistic infections

Com o objetivo de conhecer e atualizar as características clínicas e epidemiológicas dos pacientes com aids e infecções oportunistas na região de Ribeirão Preto, foram revisados os prontuários médicos de 1019 pacientes com aids, do sub - grupo IVc (CDC), atendidos no HCFMRP, no período de janeiro de 1992 a agosto de 1996.Os seguintes itens foram analisados: data do primeiro atendimento, sexo, idade, cidade em que residia, via provável de aquisição do HIV, época do primeiro exame anti -HIV positivo, número de linfócitos CD4/mm3&nbsp;por ocasião do primeiro atendimento, data da primeira manifestação infecciosa após o início do seguimento, tipo e número de complicação(ões) infecciosa(s), data do óbito e tipo de infecção(ões) diagnosticada(s) nos pacientes que faleceram. Os resultados, quando comparados com os obtidos no período de 1987 a 1991, apontam para modificações importantes em algumas características dos pacientes no segundo período, como aumento da via de transmissão heterossexual do HIV, aumento da participação de mulheres na casuística, uma tendência de diagnóstico mais precoce da infecção pelo HIV e aumento da sobrevida dos pacientes. Por outro lado, os pacientes continuam sendo acometidos por ampla gama de processos infecciosos durante a evolução da aids, com destaque para a candidíase, as pneumonias bacterianas, a neurotoxoplasmose, a pneumonia por P.carinii, a sinusite, a diarréia e a neurocriptococose. Menção especial deve ser feita à tuberculose que acometeu cerca de 30% dos pacientes durante o período de seguimento. &nbsp; &nbsp;In order to up-to-date informations about the clinical and epidemiological characteristics of AIDS patients with opportunistic infections, from the Ribeirão Preto region, we revised 1019 medical records of individuals belonging to IVc AIDS sub-group attended in HCFMRP in the period from January 1992 to August 1996. The following parameters were analyzed: date of the first medical examination, sex, age, city of residence, probable form of acquisition of HIV, time of the first anti-HIV positive test, number of CD4+/mm3 lymphocytes at the beginning of the follow-up, date of the first infectious episodes after the beginning of the follow-up, type and number of infectious episodes, date of the death and the type of infectious processes diagnosed in the patients that died. The results point out for important modifications in some characteristics of the patients over the last five years. We noted, by comparing with the results obtained in the period of 1987 to 1991, an increase in the heterosexual transmission of HIV and an increase of the number of women with AIDS; a tendency of an early diagnosis of the HIV infection and an increase in patients’ survival. In the other hand patients continued presenting a wide range of infectious processes during the AIDS evolution with emphasis for candidiasis, for bacterial pneumonia, for neuro-toxoplasmosis, for pneumocystosis, for sinusitis, for diarrhoea, and for neuro-cryptococcosis. Special mention must be done for tuberculosis, which was diagnosed in 30% of the patients during the follow-up period