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1.
Braz. j. biol ; 84: e257314, 2024. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1355908

RESUMO

Abstract Melon production in the Brazilian semi-arid region is subject to the use of marginal waters with high salinity. However, the use of regulators and bioactivators in seed treatment can mitigate the harmful effects of salts in irrigation water. In this context, the objective was to evaluate the effect of pre-germination treatments with plant regulators and bioactivator in melon seeds for the production of seedlings irrigated with biosaline water from fish farming effluent. For this, two trials with the Goldex and Grand Prix hybrids were carried out separately. A completely randomized design was used in a 4 × 3 factorial scheme (pre-germination treatments × water dilutions). In addition to the control, the seeds were treated with salicylic and gibberellic acids and thiamethoxam. The waters used for irrigation were local-supply water, fish farming effluent (biosaline water) and these diluted to 50%. Physiological and biochemical analyses were performed for fourteen days. Biosaline water (5.0 dS m-1) did not affect the emergence of Goldex melon seedlings, but compromised the establishment of the Grand Prix cultivar. Seed pre-treatments with salicylic and gibberellic acids attenuate the effects of water salinity and promote growth modulations, resulting in more vigorous melon seedlings.


Resumo A produção de meloeiro no semiárido brasileiro está sujeita a utilização de águas marginais com salinidade elevada. Entretanto, a utilização de reguladores e bioativadores no tratamento de sementes podem mitigar os efeitos nocivos dos sais na água de irrigação. Nesse sentido, objetivou-se avaliar o efeito de tratamentos pré-germinativos com fitorreguladores e bioativador em sementes de melão para a produção de mudas irrigadas com água biossalina de efluente de piscicultura. Para isso, dois ensaios com os híbridos Goldex e Grand Prix foram realizados separadamente. Utilizou-se delineamento inteiramente casualizado em esquema fatorial 4 × 3 (tratamentos pré-germinativos × diluições de água). Além do controle, as sementes foram tratadas com os ácidos salicílico e giberélico, e tiametoxam. As águas utilizadas para irrigação foram a de abastecimento local, efluente de piscicultura (água biossalina) e estas diluídas a 50%. Durante quatorze dias foram realizadas as análises fisiológicas e bioquímicas. A água biossalina (5,0 dS m-1) não afetou a emergência de plântulas de meloeiro Goldex, mas prejudicou o estabelecimento da cultivar Grand Prix. Os pré-tratamentos de sementes com os ácidos salicílico e giberélico atenuam os efeitos da salinidade da água e promovem modulações no crescimento, proporcionando mudas de meloeiro mais vigorosas.


Assuntos
Germinação , Cucurbitaceae , Sementes , Água , Plântula
2.
Methods Mol Biol ; 2566: 175-186, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36152251

RESUMO

Lipids are a heterogeneous group of substances characterized by their solubility in organic solvents and insolubility in water. Lipids can be found as normal components of different tissues and organs, and they can be affected by several pathological conditions. The histochemical identification of lipids plays an important role in the histopathological diagnosis and research, but successful staining depends on adequate fixation and processing of the tissue. Here we describe methods to fix, cryoprotect, and process tissue samples for the histochemical identification of lipids in frozen or paraffin-embedded tissues.


Assuntos
Lipídeos , Água , Formaldeído , Inclusão em Parafina/métodos , Solventes , Fixação de Tecidos/métodos
3.
Food Chem ; 400: 134032, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36055145

RESUMO

The formation mechanism of heat-induced egg yolk granules (EYGs)/sodium alginate (SA) emulsion gel was studied under pH 6.2 and 7.5. Particle size, water holding capacity, LF NMR, and protein solubility revealed that pH 7.5 increased the surface charge of EYGs and enhanced non-covalent interaction with SA, and hydrogen bonding dominated of the gel formation process. Microscopy and rheological analysis indicated that samples with 0.75% SA had the smallest particle size and highest G', with chain-like oil droplets. Excess SA (1%) led to depletion flocculation due to SA structural rearrangements around oil droplets caused by the increase in negatively charged, causing uneven network structure. The in vitro release property and storage stability of ß-carotene loaded in the EYGs/SA emulsion gel showed that SA increased storage stability and decreased bioaccessibility of ß-carotene with delayed digestion rate. These results provide a theoretical basis for the nutrient delivery system in gel foods.


Assuntos
Alginatos/química , Gema de Ovo/química , beta Caroteno/química , Emulsões/química , Géis/química , Ligação de Hidrogênio , Concentração de Íons de Hidrogênio , Imageamento por Ressonância Magnética/métodos , Tamanho da Partícula , Proteínas/química , Reologia , Solubilidade , Água/química
4.
Food Chem ; 400: 134049, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36067689

RESUMO

Novel insecticide cyetpyrafen is frequently used in various crops, however, knowledge of its fate in crops and environments is largely unexplored. In this study, an effective method was firstly established for simultaneous determination of cyetpyrafen and its metabolites (M-309 and M-391) in 13 matrices (e.g., plants and soils) to explore their fate. Mean recoveries of the three compounds ranged from 73.1 % to 118.7 % with the relative standard deviations (RSDs) less than 17.9 %. Further, after 28 days of exposure in a field soil-strawberry system, cyetpyrafen and M-309 exhibited great accumulations in strawberry leaves by foliar spray while both compounds were predominately accumulated in roots by root irrigation, where cyetpyrafen was poorly translocated within plant. An equal amount of M-309 was measured in both strawberry plants and soils indicates the extensive transformation of cyetpyrafen in soil-strawberry system. Therefore, metabolism of cyetpyrafen in foods need to be considered for its better risk assessment.


Assuntos
Produtos Agrícolas/química , Fragaria , Praguicidas/análise , Solo/química , Água/análise , Produtos Agrícolas/metabolismo , Inseticidas/análise , Inseticidas/metabolismo , Praguicidas/metabolismo , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Água/metabolismo
5.
Spectrochim Acta A Mol Biomol Spectrosc ; 284: 121779, 2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36041262

RESUMO

Online monitoring of antibiotics in the environment attracts more and more attention. Surface-enhanced Raman scattering (SERS) is a promising technique for the detection of trace amounts of antibiotics in the environment, which is fast, non-invasive and sensitive. To investigate the enrichment of trace amounts of antibiotics in water, polyethylene microplastics (PE MPs) were prepared as sorbents to simply concentrate enrofloxacin, ciprofloxacin hydrochloride monohydrate and triclosan in water, followed by the SERS measurement of antibiotics extract washed from MPs on an AgNPs@Si SERS substrate. Limit of detection of Rhodamine 6G is 2.1 × 10-12 M achieved from the AgNPs@Si SERS, indicating a high enhancement. The detection results show that SERS peaks of the antibiotics could be observed from the spectra of the extracts eluted from MPs, indicating MPs could adsorb and desorb antibiotics from water. Besides, for enrofloxacin and triclosan, the intensity of SERS measured from the MPs extracts are higher than that of directly from the spiked water, demonstrating the proposed method could lower the detectable concentration of hydrophobic antibiotics in water. Moreover, the proposed MPs sorbents combined with SERS method was applied to detect the antibiotics in real river water, with minimal detection of 10-10 M, 10-8 M, and 10-8 M achieved for enrofloxacin, ciprofloxacin hydrochloride monohydrate and triclosan, respectively. The proposed method provides a promising simple, rapid and low reagent consuming means for monitoring antibiotics in water.


Assuntos
Antibacterianos , Triclosan , Antibacterianos/análise , Ciprofloxacina , Enrofloxacina , Microplásticos , Plásticos , Polietilenos , Prata/química , Análise Espectral Raman/métodos , Tecnologia , Água
6.
Spectrochim Acta A Mol Biomol Spectrosc ; 284: 121767, 2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36041263

RESUMO

Fe3+ is the most abundant essential transition metal ion in the human body, plays a vital role in biological and environmental systems. Ethyl cellulose is one of the derivatives of cellulose. Herein, a novel ethylcellulose fluorescent probe EC-HPCB for detecting Fe3+ was prepared by grafting a flavonol derivative as both fluorophore and selective recognition group. The probe exhibited a highly specific "turn-off" fluorescence response to Fe3+, and the fluorescence color changed from yellow to colorless in the presence of Fe3+. The detection limit of EC-HPCB for Fe3+ was 2.65 × 10-7 mol/L, and the response time was as quick as 2 min. The detection mechanism was confirmed by 1H NMR and DFT calculations. Based on the good solubility and processability in organic solvent, EC-HPCB was made into coating and film with favorable fluorescent performances. Furthermore, EC-HPCB probe was successfully applied to monitor Fe3+ in real water samples, and the EC-HPCB-loaded filter paper provided a solid-state platform for detecting Fe3+ by naked eye and fluorescence method.


Assuntos
Celulose , Corantes Fluorescentes , Celulose/análogos & derivados , Flavonóis , Corantes Fluorescentes/química , Humanos , Limite de Detecção , Bifenilos Policlorados , Solventes , Água/química
7.
Spectrochim Acta A Mol Biomol Spectrosc ; 284: 121777, 2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36058171

RESUMO

A novel multicolor fluorescent nano-probe based on the hybridization of Tb3+ ion with gold nanoclusters (Au NCs) was synthesized to monitor and on-site visual assay of 2,6-pyridinedicarboxylic acid (DPA), a biomarker of bacterial spores. DPA can replace the water molecule in the center of Tb3+ and strongly coordinate with Tb3+ based on the analyte-triggered antenna effect. Simultaneously, the red fluorescence of Au NCs is not influenced after addition of DPA and can be used as steady inside fluorescence reference channel to measure background noise. On this basis, the multicolor fluorescence nano-probe based on Tb3+-doped Au NCs for fast analysis of DPA was fabricated. The linear range of this method is 0 to 12.5 µM and the limit of detection is 3.4 nM, which is well below the quantity of DPA concentration of 60 µM released by the spore transmission dose of anthrax infection. The proposed multicolor fluorescence nano-probe was successfully detecting DPA in actual sample with good sensitivity and specificity. In addition, the visual paper-based nano-probe is designed to detect DPA by using the color scanning application of smart phone. This developed platform possesses abroad application prospects with advantages of effective, convenient carrying, simple operation, good selectivity and repeatability.


Assuntos
Ouro , Térbio , Biomarcadores/análise , Corantes Fluorescentes/análise , Ácidos Picolínicos/análise , Água
8.
Spectrochim Acta A Mol Biomol Spectrosc ; 284: 121808, 2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36063734

RESUMO

The isotropic and anisotropic component Raman spectra and H NMR of N-methylpyrrolidone (NMP)/carbon tetrachloride and NMP/methanol binary mixture at different volume fractions have been collected. The polarization Raman frequencies and frequency differences of CO stretching vibration for NMP/methanol mixture show unique concentration-dependence and abrupt jump feature. It is found that the H-bond between solute and solvent does not destroy the noncoincidence (NCE) phenomenon, but has a significant synergistic effect on the NCE. Two distinctive clusters constrained by H-bond and intermolecular interactions were easily determined by means of linear extension method from abrupt jump curve. The experimental phenomena can be well explained by aggregation-induced splitting theory with the proposed dimer structure and H-bond cluster model. Applying the same methodology the conformation of NMP in water has been determined successfully. The establishment of this method will play an important role in the determination of biomolecule aggregation behavior and supramolecular self-assembly structure.


Assuntos
Metanol , Análise Espectral Raman , Tetracloreto de Carbono , Pirrolidinonas , Solventes/química , Vibração , Água/química
9.
Spectrochim Acta A Mol Biomol Spectrosc ; 284: 121781, 2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36063737

RESUMO

Polymyxin B (PMB) was an antibiotic with highly effective antibacterial effect but narrow safety interval, and its residues in food had attracted widespread attention. It was important to develop an accurate method for the rapid detection of PMB in animal foods. In this work, we had established a ratiometric sensing system based on the formation of supramolecular assemblies of pyrenyl probes, which were driven by the synergy of noncovalent forces such as multiple-electrostatic and π-π stacking interactions. Compared with the traditional fluorescence detection based on the single wavelength change, the present approach showing two-wavelength fluorescence response could reduce the interference of other factors making the experimental results more accurate. The sensor exhibited high sensitivity and selectivity with a low detection limit (28.3 nM). This method could be used to realize visual detection and had a visual detection limit of 1 µM. As we had learned yet, this was the first ratiometric sensor for PMB detection in aqueous solution. We believed all our preliminary would not only provide a complementary strategy for the detection of PMB, but also develop some new ideas for the construction of sensors for rapid antibiotic detection.


Assuntos
Polimixina B , Água , Animais , Antibacterianos , Corantes Fluorescentes/química , Limite de Detecção , Espectrometria de Fluorescência/métodos
10.
Spectrochim Acta A Mol Biomol Spectrosc ; 284: 121825, 2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36081192

RESUMO

Raman spectroscopy and stimulated Raman scattering (SRS) were used to investigate the hydrogen bonding (HB) network in 1,2-propanediol (1,2-PD)-water binary solutions. Abnormal changes in hydrogen bonds (HBs) were detected when V1,2-PD (volume fraction of the1,2-PD) was 0.4. In the case of Raman spectroscopy, the HB strength of water is weakened and then strengthened with the increase of 1,2-PD volume fraction. In the case of SRS, two new peaks at 3283 cm-1 and 3319 cm-1 were appeared, which demonstrated the appearance of ice-like structures near the methyl group and the weakening of HBs. Based on these phenomena, the HB structure of this binary system underwent a transition from H2O-H2O to H2O-1,2-PD when the V1,2-PD was 0.4 as V1,2-PD increased. This work serves as a reference value for the study of HB networks in alcohol-water binary solutions.


Assuntos
Propilenoglicol , Análise Espectral Raman , Ligação de Hidrogênio , Gelo , Análise Espectral Raman/métodos , Água/química
11.
Spectrochim Acta A Mol Biomol Spectrosc ; 284: 121818, 2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36087405

RESUMO

Determination of cesium ion in soybean oil is of high importance since the increasing risk from releasing of main component of nuclear waste cesium 137. The complex composition and high viscosity of soybean oil make it necessary to convert it into water phase by nitration before detection, so developing a simple, accurate and sensitive method for on-site sensing of Cs+ in soybean oil is still a big challenge. In this work, we report a traffic light-type ratiometric fluorescence strategy for the visual sensing of Cs+ in soybean oil based on dimensional regulation of two dimensional (PEA)2PbI4 perovskite nanosheets (NSs). The PEA+ in (PEA)2PbI4 NSs exchanged with Cs+ and lead to dimension of partial (PEA)2PbI4 NSs progressively increase from 2D to 3D CsPbI3 NCs. Resultantly, the fluorescence of (PEA)2PbI4 NSs decreases with a concomitant fluorescence enhancement of CsPbI3 NCs upon increasing the concentrations of Cs+, and the emission accordingly change from green, yellow to red with a high fluorescence colorimetric resolution up to 5.0 µM, make it successful to achieve on-site sensing of Cs+ in soybean oil just with naked eye in 5 min without any nitration, demonstrating a bright application future for determination of Cs+ in the soybean oil.


Assuntos
Resíduos Radioativos , Óleo de Soja , Compostos de Cálcio , Césio , Óxidos , Titânio , Água
12.
Spectrochim Acta A Mol Biomol Spectrosc ; 284: 121756, 2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36088740

RESUMO

The growing appearance of antibiotic-resistant strains of microorganisms originated from the widespread use and ubiquitous presence of such drugs is a major concern in the world. The development of methodologies able to detect such substances at low concentration in real water samples is mandatory to overcome this problem. Europium(III) is known to form complexes with tetracycline (TC) with photoluminescent characteristics useful for TC determination. In the present work, we synthesized for the first time carbon nanoparticles (CN) showing delayed photoluminescence using a Europium(III) doping synthesis. The new material (PCNEu) was characterized both morphologically and spectroscopically, showing an analytical photoluminescent signal in presence of TC, arising from the 5D0→7F2 transition of europium, one hundred times higher than that of the europium salt alone in presence of the antibiotic. This enhancement is a consequence of the amplifying effect exerted by nanoparticle structure itself, leading to an efficient synergistic "antenna effect" in the system PCNEu - TC. The analytical signal is affected both by pH and the nature of the buffer used, and it allows the detection of tetracycline in waters with a limit of detection of 2.18 nM and recoveries between 90 and 110%. The analytical performance of the developed methodology enables having lower limits of detection than other luminescent and chemiluminescent reported methodologies.


Assuntos
Compostos Heterocíclicos , Nanopartículas , Antibacterianos/química , Carbono/química , Európio/química , Indicadores e Reagentes , Nanopartículas/química , Tetraciclina/química , Água
13.
Spectrochim Acta A Mol Biomol Spectrosc ; 284: 121820, 2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36116204

RESUMO

We report on an innovative method to measure the Zn(II) concentration in commercial pet food samples, both wet and dry food. It is based on a colorimetric sensory polymer prepared from commercial monomers and 0.5 % of a synthetic monomer having a quinoline sensory core (N-(8-(2-azidoacetamido)quinolin-5-yl)methacrylamide). We obtained the sensory polymer as crosslinked films by thermally initiated bulk radical polymerization of the monomers of 100 µm thickness, which we punched into Ø6 mm sensory discs. The immersion of the discs in water solutions containing Zn(II) turned the fluorescence on, allowing for the titration of this cation using the G parameter of a digital picture taken to the discs. The limits of detection and quantification were 29 and 87 µg/L, respectively. Furthermore, we measured the concentration of Zn(II) even in the presence of other cations, detecting no significant interferences. Thus, in a further step, we obtained the concentration of Zn(II) from 15 commercial pet food samples, ranging from 19 to 198 mg/kg, following a simple extraction procedure and contacting the extractant with our sensory discs. These results were contrasted with that obtained by ICP-MS as a reference method.


Assuntos
Quinolinas , Polímeros Responsivos a Estímulos , Polímeros , Água , Zinco
14.
Spectrochim Acta A Mol Biomol Spectrosc ; 284: 121484, 2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-35729029

RESUMO

The aim of this work is to construct a new A2B2-type of unsymmetrical and ratiometric phthalocyanine (Pc) based-probe O-A2B2ZnPc to provide an effective solution to critical inadequacy to be experienced for the detection of hazardous Be2+. O-A2B2ZnPc enabling strong absorption and emission in Near-Infrared region (λabs-λem wavelengths of 694-712 nm) showed excellent selectivity and sensitivity toward Be2+ among competitive metal ions by both spectrophotometric and fluorometric methods. The probe with oligomeric Pc form in THF was degraded with the addition of aqueous Be2+ and arranged to J-aggregation form, resulting in a remarkably diminishing in Q-band at 694 nm as well as a new band formation at 746 nm, and a considerably decreasing in fluorescence emission. The probe has superior features for the determination of Be2+ such as high quantum efficiency and photochemical stability, rapid response (1 s), high selectivity and very low Limit of Detection (0.26 ppb and 1.5 ppb) for UV-Vis and fluorescence, respectively which are quite good values according to the permissible amount of Be2+ (4 ppb) in water as specified by World Health Organization. O-A2B2ZnPc can be shown among the best performing probes with its unique properties according to previous studies in the literature. In addition, the geometrical and spectral features of the O-A2B2ZnPc were analyzed in detail by DFT calculations.


Assuntos
Corantes Fluorescentes , Isoindóis , Corantes Fluorescentes/química , Indóis , Compostos Organometálicos , Espectrometria de Fluorescência/métodos , Água/química
15.
Food Chem ; 400: 134016, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36084588

RESUMO

This work aims to investigate antifungal, mycotoxin inhibitory efficacy of the hop essential oil (HEO) nanoemulsion and their mode of action (MOA) against Fusarium graminearum isolate, a fungal pathogen causing Fusarium Head Blight (FHB) in cereal crops. The HEO, primarily consisting of terpenes and terpenoids, was encapsulated in nanoemulsion droplets. Physically stable HEO-in-water nanoemulsion was fabricated using 0.5 wt% of tween 80 and 5 wt% oil phase comprising 30 % of Ostwald ripening inhibitor and 70 % of HEO. In terms of antifungal effect, HEO nanoemulsion could not only effectively inhibit mycelial growth and spore germination of F. graminearum isolates, but also remarkably suppress the production of deoxynivalenol (DON) and its derivatives in rice culture by applying 750 µg of HEO/g rice. Our studies on the MOA showed that HEO nanoemulsion could alter the contents of total lipid and chitin in outer cell membrane as well as damaging cytoplasmic membrane.


Assuntos
Fusarium , Micotoxinas , Óleos Voláteis , Antifúngicos/metabolismo , Antifúngicos/farmacologia , Quitina/metabolismo , Fusarium/metabolismo , Micotoxinas/metabolismo , Óleos Voláteis/metabolismo , Óleos Voláteis/farmacologia , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Polissorbatos/farmacologia , Terpenos/metabolismo , Água/metabolismo
16.
Food Chem ; 400: 134076, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36084596

RESUMO

Nonionic oil-in-water (O/W) nanoemulsion provides potential to stabilize hydrophobic bio-functional components in aqueous medium. Understanding safety of nanoemulsion droplets via investigating in vitro cell uptake and cellular substructural changes is important to achieve their practical applications. Herein, we developed a nonionic O/W nanoemulsion to stabilize representative bio-functional hydrophobic component of 9'-cis-bixin at pH 3-7 and ultraviolet (UV)-induced degradation at 365, 302, and 254 nm. In vitro cell uptake demonstrated that Caco-2 cells adequately enriched 9'-cis-bixin through fast uptake of nanoemulsion droplets within 15 min. However, excessive nanoemulsion droplets greatly decreased cell survival rate, which was due to the potential destruction of cellular substructures of mitochondria, nuclear membrane, and cell membrane. Lower nanoemulsion concentration provided no significant effects on Caco-2 cell survival. This work provided objective understanding on bio-functional component stability by nanoemulsion with in vitro safety evaluation.


Assuntos
Água , Células CACO-2 , Carotenoides , Emulsões/química , Humanos , Interações Hidrofóbicas e Hidrofílicas , Água/química
17.
Food Chem ; 400: 134085, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36084598

RESUMO

Simple, rapid, low cost, selective, and sensitive analytical method was developed using fatty acid-based ternary deep eutectic solvents (TDESs) for extraction and determination of tetracycline in honey, milk and water samples by vortex assisted (VA) microextraction and UV-vis spectrophotometer. Four different TDES were prepared by combination of nonanoic acid, dodecanoic acid, decanoic, hexanoic acid, octanoic acid. Analytical parameters such as pH, TDES types and its molar ratio, dispersive solvent types and solvent volume and salt effect were optimized. VA-TDES method was good recovery of tetracycline in the samples from 94 to 99%. The LOD and LOQ values were found 1.0 and 3.3 µg L-1, respectively. The linear range of calibration graph was 3.3 -450 µg L-1. Intra-day and inter-day precision was found 2.8-4.1% and 3.6-5.2%. Enhancement factor was found 109. The factorial design was drawn to evaluate the significant level of factors and effects of variables on the recovery of tetracycline. Standard addition method was used for the validation and accuracy of the method. Present VA-TDES method was successfully applied to real samples.


Assuntos
Mel , Microextração em Fase Líquida , Animais , Solventes Eutéticos Profundos , Ácidos Graxos/análise , Mel/análise , Limite de Detecção , Microextração em Fase Líquida/métodos , Leite/química , Solventes/química , Tetraciclina/análise , Água/química
18.
Food Chem ; 400: 133873, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36087477

RESUMO

To overcome the low production efficiency of Pickering emulsion stabilizers prepared from starch, alcohol precipitation and surface modification were applied in this study. Spherical starch nanoparticles (StNPs) (247.90 ± 1.96 nm) were prepared through nanoprecipitation. The StNPs were surface-esterified to produce starch nanoparticle acetate (StNPAc), and the physicochemical changes of the products were investigated. The contact angle (>89.56° ± 0.56°) of StNPAc (degree of substitution, 0.53) was maintained for over 30 min. The results showed that the hydrophobicity of the StNPs was improved by shielding the surface hydroxyl groups via acetylation. StNPAc was also used to produce emulsions for further evaluation of their feasibility as Pickering emulsifiers. Oil-in-water (3:7, v/v) emulsions containing 1.5 wt% StNPAc were stabilized for over 35 days without creaming. Thus, StNPAc exhibited better emulsifying capacity and storage stability than StNPs. Therefore, hydrophobic starch nanoparticles obtained by acetylation are promising stabilizers for surfactant-free Pickering emulsions.


Assuntos
Nanopartículas , Amido , Acetatos , Emulsões/química , Excipientes , Nanopartículas/química , Tamanho da Partícula , Amido/química , Água/química
19.
Food Chem ; 400: 133986, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36108446

RESUMO

Cross-processing herring co-products with antioxidant-rich helpers including lingonberry-press-cake, shrimp-shells and seaweed was reported to mitigate lipid oxidation but reduce protein yield. Here, four strategies were used to counteract such yield-reduction; optimizing solubilization/precipitation pH, increasing raw-material-to-water-ratio, replacing single-stage-toothed- by radial-discharge- high-shear-mechanical-homogenization (RD-HSMH) and ultrasonication (US). The effects of RD-HSMH and US on lipid oxidation, protein structural and functional properties were studied. Combining four strategies improved total protein yield by 5-12 %, depending on helper type. More than the confirmed antioxidant effects, cross-processing also improved protein water solubility and emulsification activity but reduced gelation properties. RD-HSMH generally improved protein emulsifying and gelation properties but reduced protein water solubility. US reduced protein water solubility and gelation properties. Altogether, it was recommended for all helpers to increase solubilization pH to 12 and raw-material-to-water-ratio to 1:6 followed by RD-HSMH at 8000 rpm for 90 s, aiming for maximum protein yield and emulsifying and gelation properties.


Assuntos
Antioxidantes , Alta do Paciente , Animais , Antioxidantes/metabolismo , Peixes/metabolismo , Manipulação de Alimentos , Humanos , Concentração de Íons de Hidrogênio , Lipídeos , Água/metabolismo
20.
Food Chem ; 398: 133855, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-35944307

RESUMO

A new carbazole-based spherical microporous polymer (Car-BDA-POP) was fabricated by employing 4,4'-biphenyldicarboxaldehyde (BDA) and carbazole as monomers via a one-step and non-metal catalyst synthetic approach. It was then explored as an adsorbent for solid-phase extraction (SPE) of some chlorophenols (CPs). Under the optimized extraction conditions, the established Car-BDA-POP-based SPE coupled with high-performance liquid chromatography ultraviolet detection showed good linearity in the concentration range of 0.1-200 ng mL-1 for water samples and 5.0-800 ng g-1 for honey samples with the determination coefficients (r2) ≥ 0.9995 for the analytes. The limits of detection (S/N = 3) for the analytes were in the range of 0.03-0.06 ng mL-1 for water samples and 1.50-2.50 ng g-1 for honey samples. The method recoveries varied from 80.0 % to 116 % in spiked real samples, with the relative standard deviations less than 9.6 %. In addition, the possible adsorption mechanism, adsorption kinetics, and adsorption isotherms were also investigated.


Assuntos
Clorofenóis , Mel , Carbazóis/análise , Clorofenóis/análise , Cromatografia Líquida de Alta Pressão/métodos , Mel/análise , Polímeros/química , Extração em Fase Sólida/métodos , Água
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