Interferência da lignina na quantificação de radicais livres no processo de compostagem

Fialho, Lucimar L.; Silva, Wilson Tadeu Lopes da; Milori, Débora Marcondes Bastos Pereira; Simões, Marcelo Luiz; Martin‐Neto, Ladislau; Saab, Sérgio da Costa

doi:10.1590/s0100-40422010000200024

Cited by 10 publications

(7 citation statements)

References 24 publications

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“…Although their origin is not fully understood, it has been suggested that these compounds are semiquinone or lignin-like free radicals, remnants of plant metabolism or produced by the oxidation of polyphenols or plant fatty acids ( 40 ). Studies suggest that the lignin is degraded by extracellular enzymes in smaller portions, which makes it susceptible to absorption by microbial cells, where it is then converted into phenols and quinones that are released with oxidative enzymes into the environment to be polymerized by the mechanisms of free radical formation ( 41 - 43 ). Alternatively, the process of pulping açaí and juçara in a depulper (or mixer) with water introduces excess air and may encourage the oxidation of fruit lipids.…”

Section: Resultsmentioning

confidence: 99%

Influence of Spray-Drying and Room Temperature Storage on the Anti- and Prooxidant Properties of Fermented Juçara Pulp

Guergoletto

Bonifácio

Barbosa

et al. 2020

Food technol. biotechnol. (Online)

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Many fruits and vegetables contain compounds with antioxidant properties, but the processing and storage conditions of the food industry may damage these beneficial compounds and produce free radicals that are associated with oxidative stress. This study aims to evaluate in vitro the antioxidant capacity and prooxidant effects of juçara pulp fermented with Lactobacillus reuteri or Lactobacillus plantarum before and after spray-drying with maltodextrin, gum arabic or gelatin and storage at 25 °C for 90 days. The antioxidant capacity was assessed by measuring the ability to scavenge reactive oxygen species (ROS) in the neutrophil respiratory burst and free radical 2,2-diphenyl-1-picryl-hydrazyl (DPPH), and by determining the total phenolic content. The prooxidant effects were analyzed as free radical formation measured by electronic paramagnetic resonance (EPR). Fermentation by both bacteria increased the antioxidant activity, while the spray-drying process decreased the content of phenolic compounds (65-85 %) and the DPPH scavenging ability, depending on the carrier usage. All of the samples inhibited ROS in the neutrophil burst, and the juçara pulp fermented by L. reuteri and dried with gum arabic exhibited the best performance. Spray-drying did not influence the intensity or type of free radicals detected by EPR. However, storage at room temperature decreased the antioxidant capacity and increased free radical formation.

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Section: Resultsmentioning

confidence: 99%

Influence of Spray-Drying and Room Temperature Storage on the Anti- and Prooxidant Properties of Fermented Juçara Pulp

Guergoletto

Bonifácio

Barbosa

et al. 2020

Food technol. biotechnol. (Online)

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“…2018 of C-C bonds of aromatic rings, indicating the presence of lignins and N=C conjugated systems (Dobbss et al, 2009). Lignin is a compound of difficult decomposition, but it contributes to the formation of humic substances from its degradation and oxidation derivatives (Zhou et al, 2014;Fialho et al, 2010).…”

Section: Results and E Discussionmentioning

confidence: 99%

Spectroscopic and elementary characterization of humic substances in organic substrates

et al. 2018

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The humic substances, major constituents of the organic matter of the substrates, play an important role in plant development, including: the availability of nutrients, the generation of negative charges (CEC) and the buffering effect. Based on this, this study aimed to use the molecular absorption spectroscopy in the ultraviolet-visible region (UV-VIS), the vibrational spectroscopy Fourier transform infrared (FTIR) and the elementary analysis CHN/O techniques to characterize the humic acid (HA) and fulvic acid (FA) fractions of the humic substances of five organic substrates, named as T1, T2, T3, T4, and T5, which were produced at the Federal University of Tocantins – Campus Gurupi. The molecular absorption spectra in UV-VIS and FTIR on the T1, T2, T3, T4 and T5 substrates showed humification, the formation of negative charges, which is related to the cation exchange capacity (CEC) and the complexation of metal ions that are considered nutrients. The biggest humification was shown for the T4 substrate, in function of its higher cabon-acid humic/carbon-acid fulvic ratio and the lower C/N ratio, allied to a negative charge generation, the low E4/E6 ratio found in the humic acid fraction. The complexation of metal nutrient ions indicates the greatest potencial of its use for seedlings production and the conservation of the chemical and physical properties of the organic substrate.

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“…Temperature analyzes were performed daily, the analysis of pH, and moisture were carried out according to Fialho et al (2010). The elemental chemical analysis to determine the C/N ratio used a TruSpec CN Analyzer (LECO® brand, St. Joseph, Mi, USA).…”

Section: Temperature Moisture Ph and C/n Ratiomentioning

confidence: 99%

Treatment of Smuggled Cigarette Tobacco and Food Solid Waste in a 2000 L Facultative Reactor

Cunha¹,

Zittel²,

Silva³

et al. 2018

Detritus

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Organic waste is among the solid waste produced worldwide. When such residue is improperly accumulated and disposed of, it generates environmental impacts, polluting soils, rivers and the air. The objective of the present study was to investigate the use of a 2000 liter capacity reactor for composting domestic organic waste, wood chips and smuggled cigarette tobacco. Physicochemical analyzes (pH, temperature, humidity and C/N ratio), biological (germination test and pathogens) and spectroscopic (UV-Vis and FTIR) analyzes were performed to monitor the process. In addition, the influence of two different C/N ratios was investigated. C/N ratio analyses and phytotoxicity tests showed that the compound reached maturity over a period of 120 days. Spectroscopic analyzes of UV-Vis and FTIR showed efficiency, indicating the degradation of compounds of simpler structure and the formation of humified compounds. The microbiological and heavy metal analyses of the final compounds revealed that the results are in accordance with the legislation. The different C/N ratios showed very close results, not affecting the composting process. Thus, the proposed treatment of domestic organic waste and smuggled cigarette tobacco in facultative reactors of 2000 liters was seen to be efficient and produced mature compound in the different C/N ratios studied.

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Interferência da lignina na quantificação de radicais livres no processo de compostagem

Cited by 10 publications

References 24 publications

Influence of Spray-Drying and Room Temperature Storage on the Anti- and Prooxidant Properties of Fermented Juçara Pulp

Influence of Spray-Drying and Room Temperature Storage on the Anti- and Prooxidant Properties of Fermented Juçara Pulp

Spectroscopic and elementary characterization of humic substances in organic substrates

Treatment of Smuggled Cigarette Tobacco and Food Solid Waste in a 2000 L Facultative Reactor

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