Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 72
Filtrar
Mais filtros











Intervalo de ano de publicação
1.
Sci Total Environ ; 950: 175317, 2024 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-39111448

RESUMO

The latent potential of active ingredients derived from agro-industrial waste remains largely untapped and offers a wealth of unexplored resources. While these types of materials have applications in various fields, their ability to benefit human health needs to be further explored and investigated. This systematic review was conducted to systematically evaluate non-clinical studies that have investigated the biological effects of fractions, extracts and bioactive compounds from agro-industrial wastes and their potential therapeutic applications. Articles were selected via PubMed, Embase and Medline using the descriptors (by-products[title/abstract]) AND (agro-industrial[title/abstract]). The systematic review was registered in the International Prospective Register of Systematic Reviews (Prospero) under the number CRD42024491021. After a detailed analysis based on inclusion and exclusion criteria, a total of 38 articles were used for data extraction and discussion of the results. Information was found from in vitro and in vivo experiments investigating a variety of residues from the agro-industry. The studies investigated peels, pomace/bagasse, pulp, seeds, aerial parts, cereals/grains and other types of waste. The most studied activities include mainly antioxidant and anti-inflammatory effects, but other activities such as antimicrobial, cytotoxic, antiproliferative, antinociceptive, hypoglycemic, antihyperglycemic and anticoagulant effects have also been described. Finally, the studies included in this review demonstrate the potential of agro-industrial waste and can drive future research with a focus on clinical application.


Assuntos
Agricultura , Resíduos Industriais , Animais , Humanos , Agricultura/métodos , Antioxidantes
2.
Bioprocess Biosyst Eng ; 47(10): 1633-1645, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38970656

RESUMO

This work aimed to define strategies to increase the bioproduction of 6 pentyl-α-pyrone (bioaroma). As first strategy, fermentations were carried out in the solid state, with agro-industrial residues: Mauritia flexuosa Liliopsida. and Manihot esculenta Crantz in isolation, conducting them with different nutrient solutions having Trichoderma harzianum as a fermenting fungus. Physicochemical characterizations, centesimal composition, lignocellulosic and mineral content and antimicrobial activity were required. Fermentations were conducted under different humidification conditions (water, nutrient solution without additives and nutrient solutions with glucose or sucrose) for 9 days. Bioaroma was quantified by gas chromatography, assisted by solid-phase microextraction. The results showed the low production of this compound in fermentations conducted with sweet cassava (around 6 ppm (w/w)). The low bioproduction with sweet cassava residues can probably be related to its starch-rich composition, homogeneous substrate, and low concentration of nutrients. Already using buriti, the absence of aroma production was detected. Probably the presence of silicon and high lignin content in buriti minimized the fungal activity, making it difficult to obtain the aroma of interest. Given the characteristics presented by the waste, a new strategy was chosen: mixing waste in a 1:1 ratio. This fermentation resulted in the production of 156.24 ppm (w/w) of aroma using the nutrient solution added with glucose. This combination, therefore, promoted more favorable environment for the process, possibly due to the presence of fermentable sugars from sweet cassava and fatty acids from the buriti peel, thus proving the possibility of an increase of around 2500% in the bioproduction of coconut aroma.


Assuntos
Manihot , Pironas , Manihot/química , Manihot/metabolismo , Pironas/metabolismo , Pironas/química , Cocos/química , Odorantes/análise , Hypocreales/metabolismo , Fermentação
3.
Bioprocess Biosyst Eng ; 47(7): 1081-1094, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38739268

RESUMO

Wheat bran is one of the most abundant by-products from grain milling, which can be used as substrate for solid-state fermentation (SSF) to obtain enzymes able to convert this agro-industrial waste into glucose syrup, which in turn can be applied for the production of different food products. The present study aimed to determine centesimal composition of wheat bran, obtain enzymatic extract that converts wheat bran into wheat glucose syrup (WGS), produce rice flakes cereal bars (RFCB), and evaluate their nutritional composition and the presence of functional compounds, as well as their antioxidant potential. Determination of centesimal composition of wheat bran demonstrated its nutritional potential. Enzymatic extract was obtained and it converted wheat bran into WGS, which were applied to rice flakes producing RFCB. These cereal bars proved to be a source of dietary fiber (1.8 g) and soluble protein (7.2 g) while RCFB produced with corn glucose syrup did not present these nutritional components. In addition, RFCB produced with WGS showed polyphenolic compounds, among them flavonoids, which exhibited antioxidant activity by DPPH and ABTS radical scavenging (47.46% and 711.89 µM Trolox Equivalent/g, respectively), and iron ion reduction (71.70 µM Trolox equivalent/g). Final product showed a decrease in caloric value and sodium content. Therefore, the present study showed that the bioprocess of SSF yields a nutritional, ecological, and functional food product, which might be of great interest for food industry, adding nutritional and functional value to a well-stablished product.


Assuntos
Antioxidantes , Fibras na Dieta , Grão Comestível , Fermentação , Glucose , Glucose/metabolismo , Antioxidantes/metabolismo , Grão Comestível/química , Oryza/química , Triticum/metabolismo , Triticum/química
4.
ACS Appl Mater Interfaces ; 16(15): 19391-19410, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38591172

RESUMO

Nowadays, bone systems have a series of consequences that compromise the quality of life mainly due to wear and decreased bioactivity, generally in elderly people and children. In this context, the combination of montmorillonite (MMT-NPs) in a vitreous system such as nanobioglass facilitates the adsorption of biomolecules on the surface and within the interlamellar spaces, enabling the entry of ions by a cation exchange process focusing on increasing the rate of bone formation. This work aims to synthesize and characterize an eco-friendly hybrid reinforcement containing MMT-NPs with nanobioglass doped with magnesium nanoparticles (MgNPs-BV). In this way, MMT-NPs@MgNPs-BV was synthesized by the impregnation method, where an experimental design was used to verify the synthesis conditions. The ideal condition by experimental design was carried out in terms of the characterization and biological activity, where we demonstrated MMT-NPs of 30% w w-1, MgNPs-BV of 6% w w-1, and a calcination temperature of 1273.15 K with a cell viability around 66.87%, an average crystallite diameter of 12.5 nm, and a contact angle of 17.7°. The characterizations confirmed the impregnation method with an average particle size of 51.4 ± 13.1 nm. The mechanical tests showed a hardness of 2.6 GPa with an apparent porosity of 22.2%, similar to human bone. MMT-NPs@MgNPs-BV showed a cell proliferation of around 96% in osteoblastic cells (OFCOL II), with the formation of the apatite phase containing a relation of Ca/P of around 1.63, a biodegradability of 82%, and rapid release of ions with a Ca/P ratio of 1.42. Therefore, the eco-friendly hybrid reinforcement with MMT-NPs and MgNPs-BV shows potential for application with a matrix for biocompatible nanocomposites for bone regeneration.


Assuntos
Bentonita , Nanopartículas , Criança , Humanos , Idoso , Qualidade de Vida , Regeneração Óssea , Íons
5.
J Environ Sci Health B ; 59(4): 131-141, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38314812

RESUMO

Small slaughterhouses generate biowaste, which for economic reasons, is generally destined for composting. Inoculating appropriate microorganisms can improve biodegradation efficiency and mitigate odor generation during the composting process and can give rise to composts with neutral or pleasant odors. Therefore, the aim of this study was to compare the odor intensity reduction of compost generated with and without a formulated inoculum (Saccharomyces cerevisiae, Bacillus subtilis, and Rhodopseudomonas palustris). A set of experimental data was collected and analyzed according to the German "Verein Deutscher Ingenieure" odor protocol. The results showed that adding microorganisms was effective in reducing unpleasant odors in all three composts generated from swine, cattle, and poultry slaughterhouse by-products during both summer and winter seasons. Additionally, soil odor was predominant in composts that were inoculated in the two tested seasons (i.e., summer and winter). On the other hand, composts without inoculation had odors similar to peat for swine compost, ammonia for cattle compost, and manure for poultry compost, regardless of the season tested. Overall, composting process with appropriate inoculum can help in the correct disposal of slaughterhouse wastes by transforming organic matter into composts, which can have economic and environmental value as a soil conditioner and/or fertilizer.


Assuntos
Compostagem , Animais , Bovinos , Suínos , Matadouros , Odorantes/prevenção & controle , Solo , Biodegradação Ambiental , Esterco
6.
Food Chem ; 443: 138515, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38277934

RESUMO

In light of the growing demand for alternative protein sources, laboratory-grown meat has been proposed as a potential solution to the challenges posed by conventional meat production. Cultured meat does not require animal slaughter and uses sustainable production methods, contributing to animal welfare, human health, and environmental sustainability. However, some challenges still need to be addressed in cultured meat production, such as the use of fetal bovine serum for medium supplementation. This ingredient has limited availability, increases production costs, and raises ethical concerns. This review explores the potential of non-animal protein hydrolysates derived from agro-industrial wastes as substitutes for critical components of fetal bovine serum in cultured meat production. Despite the lack of standardization of hydrolysate composition, the potential benefits of this alternative protein source may outweigh its disadvantages. Future research holds promise for increasing the accessibility of cultured meat.


Assuntos
Resíduos Industriais , Hidrolisados de Proteína , Animais , Carne in vitro , Carne/análise , Soroalbumina Bovina
7.
Environ Res ; 247: 118220, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38242422

RESUMO

The work investigates the potential of peanut shells, an abundant agro-industrial waste, to serve as an adsorbent precursor for the effective and simple treatment of effluents loaded with cadmium and nickel ions. Among the adsorbents prepared, carbonized peanut shell (CCarb), due to its higher adsorption capacity, proved to be the most effective compared to carbonized and activated peanut shell (CATQ). The carbonization process led to structural changes, which resulted in an increase in surface area (around 6 times more in CATQ) and pore volume (around 3 times more in CATQ). Even so, the amount of H+ acid sites due to acid activation produced unfavorable effects for adsorption. Hydroxyl, carboxyl and carbonyl groups were identified on the adsorbent surface which presented favorable charges for metal adsorption. This improvement propels the carbonized variant to the forefront, demonstrating the highest adsorption capacity and reaching equilibrium in less than 90 and 60 min for cadmium and nickel ions, respectively. In both monocomponent and bicomponent systems concentrations greater than 40 ppm signify an increase in adsorption capacity for Ni2+. The experimental data best fit the Freundlich model, showing maximum adsorption capacities of 17.04 mg g-1 for cadmium and 31.28 mg g-1 for nickel. Despite the antagonistic effect observed in the bicomponent system, this study concludes by underlining the promise of activated carbon from peanut shells to harmonize technical and environmental concerns.


Assuntos
Níquel , Poluentes Químicos da Água , Cádmio , Arachis , Adsorção , Bismuto , Íons , Cinética , Poluentes Químicos da Água/análise , Concentração de Íons de Hidrogênio
8.
Prep Biochem Biotechnol ; 54(1): 1-11, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37071540

RESUMO

This study describes the production, characterization and application of an endoglucanase from Penicillium roqueforti using lignocellulosic agro-industrial wastes as the substrate during solid-state fermentation. The endoglucanase was generated after culturing with different agro-industrial wastes for 96 h without any pretreatment. The highest activity was obtained at 50 °C and pH 4.0. Additionally, the enzyme showed stability in the temperature and pH ranges of 40-80 °C and 4.0-5.0, respectively. The addition of Ca2+, Zn2+, Mg2+, and Cu2+ increased enzymatic activity. Halotolerance as a characteristic of the enzyme was confirmed when its activity increased by 35% on addition of 2 M NaCl. The endoglucanase saccharified sugarcane bagasse, coconut shell, wheat bran, cocoa fruit shell, and cocoa seed husk. The Box-Behnken design was employed to optimize fermentable sugar production by evaluating the following parameters: time, substrate, and enzyme concentration. Under ideal conditions, 253.19 mg/g of fermentable sugars were obtained following the saccharification of wheat bran, which is 41.5 times higher than that obtained without optimizing. This study presents a thermostable, halotolerant endoglucanase that is resistant to metal ions and organic solvents with the potential to be applied in producing fermentable sugars for manufacturing biofuels from agro-industrial wastes.


Assuntos
Celulase , Saccharum , Celulase/química , Celulose , Fibras na Dieta , Fermentação , Resíduos Industriais , Projetos de Pesquisa , Saccharum/metabolismo , Açúcares , Cálcio/química , Cobre/química , Zinco/química , Magnésio/química
9.
Environ Res ; 244: 117879, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38086503

RESUMO

Biosurfactants are eco-friendly compounds with unique properties and promising potential as sustainable alternatives to chemical surfactants. The current review explores the multifaceted nature of biosurfactant production and applications, highlighting key fermentative parameters and microorganisms able to convert carbon-containing sources into biosurfactants. A spotlight is given on biosurfactants' obstacles in the global market, focusing on production costs and the challenges of large-scale synthesis. Innovative approaches to valorizing agro-industrial waste were discussed, documenting the utilization of lignocellulosic waste, food waste, oily waste, and agro-industrial wastewater in the segment. This strategy strongly contributes to large-scale, cost-effective, and environmentally friendly biosurfactant production, while the recent advances in waste valorization pave the way for a sustainable society.


Assuntos
Resíduos Industriais , Eliminação de Resíduos , Alimentos , Fermentação , Tensoativos/química
10.
Materials (Basel) ; 16(19)2023 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-37834532

RESUMO

This article presents an experimental study to analyze the mechanical properties of a soil stabilized with ordinary Portland cement (OPC) under a sustainable approach consisting of a significant substitution of OPC for sugarcane bagasse ash (SCBA) to reduce the quantity of cement used in the stabilization, reaching the necessary mechanical requirements for its use as a subgrade layer. Soil specimens were elaborated with 3%, 5%, and 7% OPC as a stabilizing agent by weight of the soil. These mixtures were then partially substituted with 25%, 50%, and 75% SCBA, with these percentages being by weight of the stabilizer (OPC). Compaction, compressive strength, and California bearing ratio (CBR) tests were performed to evaluate the mechanical properties of the specimens. The results indicate that a 25% substitution of OPC by SCBA shows a similar performance to the mixture with only Portland cement, so a reduction in OPC use can be made. Further, with a substitution of 100% OPC by SCBA, the CBR of natural soil without stabilizers is improved.

11.
Braz J Microbiol ; 54(4): 2719-2731, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37783938

RESUMO

In this work, a new isolate yeast, namely Rhodotorula toruloides KP324973, was examined for ß-carotene production from corn steep liquor (CSL) as a sole carbon source because CSL as the by-product of corn wet-milling process mainly enriched from the water-soluble carbohydrates. The studies were preliminary performed at the shaken flasks, and then developed at batch and fed-batch modes in a bubble column reactor (BCR). Application of the BCR improved the carotenogenesis of the cells in comparison with shaken flasks and the specific ß-carotene production rate (Rp) and the yield of ß-carotene production from the total reducing sugars (YP/TRS) reached 2.23 mg gcell-1 h-1 and 36.82 mg gTRS-1, respectively. Further studies were carried out to optimize the operational factors of the BCR for a fed-batch production by the response surface methodology. An optimal condition at a feed flow rate of 2.5 mL h-1, temperature 11.7°C, and initial pH of 6.1 obtained the highest Rp = 12.31 mg gcell-1 h-1 and YP/TRS = 97.18 mg gTRS-1.


Assuntos
Rhodotorula , beta Caroteno , Zea mays , Reatores Biológicos , Fermentação
12.
World J Microbiol Biotechnol ; 39(12): 323, 2023 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-37773232

RESUMO

The present study describes practical implication of bioaugmentation and biostimulation processes for bioremediation of an industrial soil chronically contaminated by hydrocarbons. For this purpose, biomass production of six autochthonous hydrocarbon-degrading bacteria were evaluated as inoculum of bioaugmentation strategy, by testing carbon and nitrogen sources included co-products and agro-industrial waste as sustainable and low-cost components of the growth medium. Otherwise, biostimulation was approached by the addition of optimized concentration of nitrogen and phosphorus. Microcosm assays showed that total hydrocarbons (TH) were significantly removed from chronically contaminated soil undergoing bioremediation treatment. Systems Mix (bioaugmentation); N,P (biostimulation) and Mix + N,P (bioaugmentation and biostimulation) reached higher TH removal, being 89.85%, 91.00%, 93.04%, respectively, comparing to 77.83% of system C (natural attenuation) at 90 days. The increased heterotrophic aerobic bacteria and hydrocarbon degrading bacteria counts were according to TH biodegrading process during the experiments. Our results showed that biostimulation with nutrients represent a valuable alternative tool to treat a chronically hydrocarbon-contaminated industrial soil, while bioaugmentation with a consortium of hydrocarbon degrading bacteria would be justified when the soil has a low amount of endogenous degrading microorganisms. Furthermore, the production of inoculum for application in bioaugmentation using low-cost substrates, such as industrial waste, would lead to the development of an environmentally friendly and attractive process in terms of cost-benefit.


Assuntos
Petróleo , Poluentes do Solo , Biodegradação Ambiental , Resíduos Industriais , Petróleo/análise , Solo/química , Poluentes do Solo/análise , Hidrocarbonetos , Bactérias , Nitrogênio , Microbiologia do Solo
13.
Molecules ; 28(14)2023 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-37513363

RESUMO

Theobroma cacao agro-industrial waste (WTC) has been characterized and tested as an effective biosorbent to remove Cd(II) from aqueous media. At the optimum pH of 5.0, a maximum adsorption capacity of qe,max = 58.5 mg g-1 was determined. The structural and morphological characterization have been conducted by FTIR, SEM/EDX, and TGA measurements. The SEM/EDX results confirmed that the metals are adsorbed on the surface. C-O-C, OH, CH, NH, and C=O functional groups were identified by FTIR. TGA results were consistent with the presence of hemicellulose. Biosorption kinetics were rapid during the first 30 min and then reached equilibrium. The corresponding experimental data were well fitted to pseudo-first and -second order models, the latter being the best. The biosorption isotherm data were also well fitted to Temkin, Langmuir, and Freundlich models, showing that several sorption mechanisms may be involved in the Cd(II) biosorption process, which was characterized as exothermic (ΔH0 < 0), feasible, and spontaneous (ΔG0 < 0). In binary (Cd-Pb and Cd-Cu) and ternary (Cd-Pb-Cu) systems, Cu(II) and particularly Pb(II) co-cations exert strong antagonistic effects. Using HNO3, effective good regeneration of WTC was obtained to efficiently remove Cd(II) up to three times.

14.
Food Res Int ; 169: 112876, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37254323

RESUMO

Environmental and food security challenges due to a growing world population may be overcome by using alternative protein sources for the human diet. By-products from edible oil processing industries are potential sources due to their high protein content. Pumpkin seed meals were evaluated regarding proximate composition, in vitro protein digestibility (IVPD), amino acid profile and score, and antinutritional factors. Conventional thermal processing, microwave, and ultrasound treatments impact on samples' nutritional quality were assessed using a central composite experimental design. Raw pumpkin seed meal presented up to 45% protein content and 86% IVPD. Processing increased IVPD up to 96%, with optimized conditions of 87.8 °C, pH8.0, and 37 min, for all processes. Lysine was the only limiting amino acid for raw and processed samples. Phytic acid decreased by 31%, while trypsin inhibitory activity was reduced by 84%. Pumpkin seed by-product is a promising high-quality plant protein source for food formulations.


Assuntos
Cucurbita , Humanos , Cucurbita/química , Manipulação de Alimentos , Aminoácidos/análise , Proteínas de Plantas/análise , Refeições , Sementes/química
15.
Polymers (Basel) ; 15(3)2023 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-36771829

RESUMO

In the context of the preservation of natural resources, researchers show a growing interest in developing eco-friendly materials based on recycled polymers and natural fiber biocomposites to minimize plastic and agroindustrial waste pollution. The development of new materials must be integrated within the circular economy concepts to guarantee sustainable production. In parallel, fused deposition modeling, an additive manufacturing technology, provides the opportunity to use these new materials in an efficient and sustainable manner. This review presents the context of plastics and agro-industrial fiber pollution, followed by the opportunity to give them added value by applying circular economy concepts and implementing these residues to develop new materials for the manufacture of fused deposition modeling 3D printing technique feedstock. Colombian perspective is highlighted since 3D printing technology is growing there, and Colombian biodiversity represents a high reservoir of materials. Also, recycling in Colombia promotes compliance with the 2030 Agenda and the Sustainable Development Goals.

16.
J Microencapsul ; 40(3): 171-185, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36803148

RESUMO

This study aimed to produce and characterise microparticles produced from barley residue proteins (BRP) enriched with ß-carotene. The microparticles were obtained by freeze-drying five emulsion formulations with 0.5% w/w whey protein concentrate and different concentrations of maltodextrin and BRP (0, 1.5, 3.0, 4.5 and 6.0% w/w), with the dispersed phase consisting of corn oil enriched with ß-carotene. The mixtures were mechanically mixed and sonicated, the formed emulsions were freeze-drying. The microparticles obtained were tested for encapsulation efficiency, humidity, hygroscopicity, apparent density, scanning electron microscopy (SEM), accelerated stability and bioaccessibility. Microparticles produced with the emulsion containing 6% w/w BRP had lower moisture content (3.47 ± 0.05%), higher encapsulation efficiency (69.11 ± 3.36%), bioaccessibility value of 84.1% and greater ß-carotene protection against thermal degradation. SEM analysis showed that microparticles had sizes ranging from 74.4 to 244.8 µm. These results show that BRP are viable for the microencapsulation of bioactive compounds by freeze-drying.


Assuntos
Hordeum , beta Caroteno , beta Caroteno/química , Emulsões/química , Cerveja , Composição de Medicamentos/métodos , Proteínas do Soro do Leite
17.
Compr Rev Food Sci Food Saf ; 22(2): 1148-1183, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36710406

RESUMO

The ideal food packaging materials are recyclable, biodegradable, and compostable. Starch from plant sources, such as tubers, legumes, cereals, and agro-industrial plant residues, is considered one of the most suitable biopolymers for producing biodegradable films due to its natural abundance and low cost. The chemical modification of starch makes it possible to produce films with better technological properties by changing the functional groups into starch. Using biopolymers extracted from agro-industrial waste can add value to a raw material that would otherwise be discarded. The recent COVID-19 pandemic has driven a rise in demand for single-use plastics, intensifying pressure on this already out-of-control issue. This review provides an overview of biopolymers, with a particular focus on starch, to develop sustainable materials for food packaging. This study summarizes the methods and provides a potential approach to starch modification for improving the mechanical and barrier properties of starch-based films. This review also updates some trends pointed out by the food packaging sector in the last years, considering the impacts of the COVID-19 pandemic. Perspectives to achieve more sustainable food packaging toward a more circular economy are drawn.


Assuntos
COVID-19 , Embalagem de Alimentos , Humanos , Embalagem de Alimentos/métodos , Amido/química , Pandemias , Extratos Vegetais/química
18.
Environ Sci Pollut Res Int ; 30(8): 21494-21511, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36272000

RESUMO

Rice is among the main foods produced in the world and is part of the daily diet of most families. The main waste from rice processing is rice husk (RH), which has been used as biomass for energy generation through combustion. In this process, rice husk ash (RHA) is generated as a residue, and its silica (SiO2) content varies from 85 to 98%. The present work describes the study of the extraction of silica from RHA by the ultrasound-assisted sol-gel method. An experimental design based on the response surface methodology (RSM) with the symmetrical, second-order rotational central composite design (RCCD) was applied to determine the best extraction conditions considering extraction time and molar ratio (n) as variables = nNaOH/nSilica). These optimal conditions were then applied to three ash samples, two obtained by the combustion process in a boiler furnace, with a mobile grate system (RHAC1 and RHAC2), and one obtained by the pyrolysis process (RHAP) carried out in a fixed bed reactor. Results showed that a molar ratio of 4.4, and an extraction time of 107 min were the best extraction conditions, leading to a yield of 73.3% for RHAP, 43.9% for RHAC1, and 31.1% for RHAC2. It was found that the extraction yield and textural properties of the silica obtained depend on the characteristics of the ash used. The silica extracted from RHAC1 presented a surface area of 465 m2.g-1, mesopores of 4.69 nm, purity greater than 95%, and an ultra-fine granulometric distribution, reaching nanoparticle dimensions, characteristics comparable to commercially available silicas.


Assuntos
Oryza , Dióxido de Silício , Humanos , Dióxido de Silício/química , Oryza/química
19.
Int J Biol Macromol ; 225: 658-672, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36395939

RESUMO

Cassava starch is one of the most available and cost-effective biopolymers. This work aimed to apply a bibliometric methodology to identify the most impactful scientific data on cassava starch and its residues for food packaging in the last ten years. As a result, an increasing interest in this subject has been observed, mainly in the past five years. Among the 85 selected scientific publications, Brazil and China have been leading the research on starch-based films, accounting for 39 % of the total. The International Journal of Biological Macromolecules was the main scientific source of information. Besides cassava starch, 41.18 % of these studies added other biopolymers, 5.88 % added synthetic polymers, and 4.71 % added a combination of both. Studies analyzed suggested that different modifications in starch can improve films' mechanical and barrier properties. In addition, 52.94 % of articles evaluated the film's bioactivity. Still, only 37.65 % assessed the performance of those films as food packaging, suggesting that more studies should be conducted on assessing the potential of these alternative packages. Future research should consider scale-up methods for film production, including cost analysis, assessment life cycle, and the impact on the safety and quality of a broader range of foods.


Assuntos
Embalagem de Alimentos , Manihot , Embalagem de Alimentos/métodos , Manihot/química , Amido/química , Polímeros/química , Brasil
20.
Artigo em Inglês | MEDLINE | ID: mdl-36554550

RESUMO

This research focused on the use of residual fiber from oil palm (Elaeis guineensis) for Ni (II) adsorption in a packed bed column. An analysis was conducted on the effect and statistical incidence of changes in temperature, adsorbent particle size, and bed height on the adsorption process. The results showed that particle size and bed height significantly affect the adsorption of Ni (II) ions, reaching adsorption efficiencies between 87.24 and 99.86%. A maximum adsorption capacity of 13.48 mg/g was obtained in the bed with a break time of 180 min. The Ni (II) adsorption in the dynamic system was evaluated by the analysis of the breakage curve with different theoretical models: Yoon-Nelson, dose-response, and Adams-Bohart; the dose-response model was the most appropriate to describe the behavior of the packed bed with an R2 of 84.56%. The breakthrough curve obtained from Aspen Adsorption® appropriately describes the experimental data with an R2 of 0.999. These results indicate that the evaluated bioadsorbent can be recommended for the elimination of Ni (II) in aqueous solutions in a dynamic system, and the simulation of the process can be a tool for the scalability of the process.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Níquel , Adsorção , Tamanho da Partícula , Água , Temperatura , Purificação da Água/métodos , Poluentes Químicos da Água/análise
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA