Assay for lipid peroxides in animal tissues by thiobarbituric acid reaction

Following scrutiny of present biofuels, algae are seriously considered as feedstocks for next-generation biofuels production. Their high productivity and the associated high lipid yields make them attractive options. In this review, we analyse a number aspects of large-scale lipid and overall algal biomass production from a biochemical and energetic standpoint. We illustrate that the maximum conversion efficiency of total solar energy into primary photosynthetic organic products falls in the region of 10%. Biomass biochemical composition further conditions this yield: 30 and 50% of the primary product mass is lost on producing cell protein and lipid. Obtained yields are one third to one tenth of the theoretical ones. Wasted energy from captured photons is a major loss term and a major challenge in maximising mass algal production. Using irradiance data and kinetic parameters derived from reported field studies, we produce a simple model of algal biomass production and its variation with latitude and lipid content. An economic analysis of algal biomass production considers a number of scenarios and the effect of changing individual parameters. Our main conclusions are that: (i) the biochemical composition of the biomass influences the economics, in particular, increased lipid content reduces other valuable compounds in the biomass; (ii) the “biofuel only” option is unlikely to be economically viable; and (iii) among the hardest problems in assessing the economics are the cost of the CO2 supply and uncertain nature of downstream processing. We conclude by considering the pressing research and development needs.

Microalgae as biodiesel & biomass feedstocks: Review & analysis of the biochemistry, energetics & economics

Microalgae are a group of unicellular or simple multicellular photosynthetic microorganisms that can fix CO2 efficiently from different sources, including the atmosphere, industrial exhaust gases, and soluble carbonate salts. Combination of CO2 fixation, biofuel production, and wastewater treatment may provide a very promising alternative to current CO2 mitigation strategies.

CO2 bio-mitigation using microalgae

Myoglobin and lipid oxidation interactions: mechanistic bases and control

Lipids in health and disease.

https://www.versta.org/wp-content/uploads/2012/10/Brazil_Fruits.pdf

Bioactive compounds and antioxidant capacities of 18 non-traditional tropical fruits from Brazil

El Brazil es considerado un de los principales paises productores de zumos de frutos, ocupando en concreto la tercera posicion respecto a esto. La diversidad de frutos en el mercado es cada vez mayor, introduciendose diariamente nuevos frutos tropicales cuyas propiedades y actividades no estan aun totalmente determinadas. El gobierno brasileno apoya el comercio exterior de frutos, invirtiendo fondos en exposiciones que promueven y situan a los nuevos productos en los paises de la Union Europea, tal como la "Brazilian Fruit Festival" que promociona frutos in natura, pulpas congeladas y zumos procesados. Se publican cada vez en mayor numero nuevas investigaciones que asocian el consumo de frutas con efectos beneficiosos para la salud humana. Este trabajo tiene por objeto la determinacion del indice de fenoles totales (FT), antocianos totales (AT) y la capacidad antioxidante de las pulpas de frutos comerciales congelados, aplicando los metodos espectrofotometrico quimicos mas en boga para la determinacion de la actividad antioxidante (ABTS, DPPH y DMPD). Se ha determinado la capacidad antioxidante de las pulpas de los frutos tropicales de mayor consumo en el mercado del sur de Brazil (mora, uva, acai, guayaba, fresa, acerola, pina, mango, graviola, cupuacu y maracuya) aplicando el metodo ABTS con medidas a dos tiempos (1 y 7 minutos), DPPH (30 y 60 minutos) y DMPD (10 minutos). Los valores TEAC (capacidad antioxidante equivalente al Trolox) obtenidos de las pulpas oscilan entre minimos y maximos de 2,0 y 67,2 µmol/g aplicando el ensayo ABTS, 1,02 y 67,0 µmol/g aplicando DPPH y 4,2 y 46,6 µmol/g aplicando DMPD. La capacidad antioxidante obtenida por los metodos ABTS y DPPH se encuentra correlacionada con el contenido de compuestos fenolicos y antocianos.

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Aplicación de diversos métodos químicos para determinar actividad antioxidante en pulpa de frutos

Spirulina maxima, which is used as a food additive, is a microalga rich in protein and other essential nutrients. Spirulina contains phenolic acids, tocopherols and beta-carotene which are known to exhibit antioxidant properties. The aim of the present study was to evaluate the antioxidant capacity of a Spirulina extract. The antioxidant activity of a methanolic extract of Spirulina was determined in vitro and in vivo. The in vitro antioxidant capacity was tested on a brain homogenate incubated with and without the extract at 37 degrees C. The IC50 (concentration which causes a 50% reduction of oxidation) of the extract in this system was 0.18 mg/ml. The in vivo antioxidant capacity was evaluated in plasma and liver of animals receiving a daily dose of 5 mg for 2 and 7 weeks. Plasma antioxidant capacity was measured in brain homogenate incubated for 1 h at 37 degrees C. The production of oxidized compounds in liver after 2 h of incubation at 37 degrees C was measured in terms of thiobarbituric acid reactant substances (TBARS) in control and experimental groups. Upon treatment, the antioxidant capacity of plasma was 71% for the experimental group and 54% for the control group. Data from liver spontaneous peroxidation studies were not significantly different between groups. The amounts of phenolic acids, alpha-tocopherol and beta-carotene were determined in Spirulina extracts. The results obtained indicate that Spirulina provides some antioxidant protection for both in vitro and in vivo systems.

/pdf/antioxidant-activity-of-the-microalga-spirulina-maxima-18jg038fbq.pdf

Antioxidant activity of the microalga Spirulina maxima

The knowledge of the chemical composition of foods is basic for evaluate the nutrients availability and its consumption for the population. In this work, the pulp and the almond of pequi fruit (Caryocar brasiliense, Camb.) were characterized by the centesimal composition and the presence of nutrients. The results showed high amount of lipids and in the fatty acids profile, the oleic fatty acid was the main component. The presence between high unsaturated fatty acids and antioxidant compounds (phenolic acids and carotenoids) was correlated with the fruit protection. In the pulp was observed too high amount of alimentary fiber. These results are suggesting the pequi utilization in a healthful diet preparation.

/pdf/composicao-quimica-e-compostos-bioativos-presentes-na-polpa-227s1xfhjk.pdf

Composição química e compostos bioativos presentes na polpa e na amêndoa do pequi (Caryocar brasiliense, Camb.)

Justification Lipid oxidation is one of the major changes that can occur during processing, distribution, storage and final preparation of foods. The oxidation could be prevented by adding synthetic or natural antioxidants in spite of safety of synthetic ones has been questioned. This situation promotes increasing demand for food additives of natural origin. Objective The objective of this study was to evaluate the antioxidant activity of cinnamon extracts. Methods Cinnamon samples were obtained at local market, milled (32 mesh sieve) and submitted to sequential extraction using as solvents: ether, methanol and water. The antioxidant activity in the extracts was measured by the b-carotene/linoleic acid system, at 50 degrees C and absorbances reading at 470 nm every 15 min intervals for 120 min. Two controls were used in this determination: one with synthetic antioxidant (BHT, 100 ppm) and other without antioxidant. The water extract was fraccionated using silica Gel 60 and 60G and through chromatographic processes: thin layer, (T.L.C.) and column, using BAW as mobile phase and ethylacetate, petroleum ether, methanol and water as eluent, respectively. Results The etheric (0.69 mg), methanolic (0.88 mg) and aqueous (0.44 mg) cinnamon extracts, inhibited the oxidative process in 68%; 95.5% and 87.5% respectively. The BHT control inhibited 80% oxidation. The spray reagents (1) beta-carotene/linoleic acid and (2) Fe Cl3/K3 Fe (CN)4 1% sol, showed spots in T.L.C. with antioxidant activity (1) and blue color (2), indicating the presence of phenolic compounds with Rf values of 0.50. Five fractions were obtained by column partition with antioxidant activity and the presence of phenolic compounds. Significance These results suggest that the cinnamon extracts can be used as food antioxidant together with the improvement of food palatability. Further studies are in processing of analysing the sinergic association of extracts with synthetic antioxidant and to identify compounds with antioxidant activity in cinnamon extracts.

Jorge Mancini-Filho

Papers

Bioactive compounds and antioxidant capacities of 18 non-traditional tropical fruits from Brazil

Aplicación de diversos métodos químicos para determinar actividad antioxidante en pulpa de frutos

Antioxidant activity of the microalga Spirulina maxima

Composição química e compostos bioativos presentes na polpa e na amêndoa do pequi (Caryocar brasiliense, Camb.)

Antioxidant activity of cinnamon (Cinnamomum Zeylanicum, Breyne) extracts.