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1.
Food Chem ; 366: 130533, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34274704

RESUMO

We performed a multiscale study to understand the impact of pure exogenous compounds at low concentration on the crystallization of triacylglycerols (TAGs) in anhydrous milk fat (AMF). We selected butyric acid, an inhibitor of crystallization, and palmitic acid, a promotor, to investigate the influence of the chain length. Tripalmitin was also used as a promotor to assess the impact of fatty acid esterification. Melted blends containing the additives (1 wt%) were quenched at 25 °C. X-ray scattering data showed that AMF TAGs crystallized directly in the ß'-2L form. The presence of additives did not modify the nanostructure of TAG crystals. However, they significantly altered the microstructure of AMF, as revealed by polarized light microscopy and rheology. This study emphasizes the interest of a multiscale approach to gain knowledge about the behavior of complex fat blends and of the use of modulators at low concentration to monitor their textural properties.


Assuntos
Ácidos Graxos não Esterificados , Nanoestruturas , Animais , Cristalização , Ésteres , Leite
2.
Food Chem ; 366: 130554, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34284188

RESUMO

Standard fermentation (SF) mainly affected the metabolism of glycerophospholipid and sphingolipid, and increased the total lipid content of goat milk. Content of total lipid was decreased by magnetic fermentation compared with SF, mainly due to triacylglycerol and diacylglycerol. Comprehensive characteristic of lipids dynamic changes during standard and magnetic fermentation was performed using high-throughput quantitative lipidomics. Totally, 488 lipid molecular species covering 12 subclasses were detected, and triacylglycerol was the highest levels, followed by diacylglycerol and phosphoethanolamine in the whole fermentation stage. Specifically, except for ceramide and simple Glc series, the content of all polar lipids in SF was dropped and neutral lipids subjoined. Compared with SF, the decrease of triacylglycerol (1752.47 to 784.78 µg/mL), diacylglycerol (60.36 to 24.89 µg/mL) and simple Glc series (4.36 to 2.40 µg/mL) were observed, while ceramide (6.54 to 25.87 µg/mL) increased, suggesting magnetic fermentation as effective approach to potentially improve the nutritional of goat milk.


Assuntos
Lipídeos , Leite , Animais , Fermentação , Cabras , Lipídeos/análise , Fenômenos Magnéticos , Leite/química , Valor Nutritivo
3.
Talanta ; 236: 122833, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34635223

RESUMO

A dynamic pH junction was used in capillary electrophoresis (CE-DAD) to on-line preconcentrate, separate, and determine trace amounts of sulfonamide antibiotics (SAs) in milk and yoghurt samples in this study. A sample matrix with 0.15% acetic acid and 10% methanol (MeOH) at a pH of 4.0, and a background electrolyte (BGE) that contained 35 mM sodium citrate with 10% MeOH at a pH of 8.5, and an acidic barrage of 0.4% acetic acid with 10% MeOH at a pH of 2.5 were utilised to achieve a stacking effect for SAs through a dynamic pH junction. Under optimised conditions, the proposed preconcentration method showed good linearity (30-500 ng/mL, r2 ≥ 0.9940), low limits of detection (LODs) of 4.1-6.3 ng/mL, and acceptable analytes recovery (81.2-106.9%) with relative standard deviations (RSDs) within 5.3-13.7 (n = 9). The limits of quantification (LOQs) were below the maximum residue limit approved by the European Union (EU) in this type of matrices. Sensitivity enhancement factors of up to 129 were reached with the optimised dynamic pH junction using CE with a diode array detector (DAD). The method was used to determine SAs in fresh milk, low-fat milk, full-cream milk, and yoghurt samples.


Assuntos
Antibacterianos , Iogurte , Animais , Eletroforese Capilar , Concentração de Íons de Hidrogênio , Leite , Sulfonamidas
4.
Talanta ; 236: 122842, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34635232

RESUMO

A fluorescent aptasensor based on sensitized terbium(III) luminescence was constructed to detect melamine in milk. Tb3+ as the fluorescence probe can be sensitized by a guanine-rich single-stranded DNA sequence, so the complementary sequence of the polythymidine aptamer (cDNA) was modified with six consecutive guanine bases (G6). In the absence of melamine, melamine aptamer combined with cDNA to form a double helix structure, and G6 hybridized with the extended cytosine bases in the aptamer, resulting in low fluorescence intensity of Tb3+. In the presence of melamine, cDNA was released due to the specific recognition of melamine to the aptamer, resulting in stronger sensitized fluorescence intensity of Tb3+. Under the optimum conditions, the linear concentration of melamine in the milk ranged from 1.0 µg/mL to 10.0 µg/mL. This aptasensor can be used for the accurate and rapid detection of melamine in milk with a detection limit of 0.02 µg/mL, and has the advantages of high sensitivity, high efficiency, simple operation and low cost.


Assuntos
Luminescência , Leite , Animais , Limite de Detecção , Leite/química , Triazinas/análise
5.
Food Chem ; 369: 130998, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34507088

RESUMO

High Temperature-Short Time (HTST) pasteurization was proposed as an alternative to Holder pasteurization (HOP) to increase the retention of specific human milk (HM) bioactive proteins. The present study explored whether HTST and HOP differently affect peptide release during simulated preterm infant gastrointestinal digestion. Raw (RHM), HOP- and HTST- pasteurized HM were digested using an in vitro dynamic system, and the identified peptides were analyzed by mass spectrometry and multivariate statistics. Before digestion, 158 peptides were identified in either RHM, HTST- or HOP- HM, mostly (84.4%) originating from ß-casein (CASB). During gastric digestion, HOP-HM presented a greater number and more abundant specific CASB peptides. A delayed release of peptides was observed in RHM during the intestinal phase, with respect to both pasteurized HM. Although limited to gastric digestion, the HM peptidomic profile differed according to the pasteurization type, and the pattern of the HTST peptides showed a greater similarity with RHM.


Assuntos
Leite Humano , Pasteurização , Animais , Digestão , Humanos , Lactente , Recém-Nascido , Recém-Nascido Prematuro , Leite , Peptídeos , Temperatura
6.
Food Chem ; 369: 130886, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34455320

RESUMO

A simple and sensitive method based on surface molecularly imprinted solid-phase extraction (SMISPE) combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed to determine the residues of vancomycin (VCM) and norvancomycin (NVCM) in milk samples. The imprinted polymer prepared with teicoplanin as a virtual template can specifically recognize VCM and NVCM. The samples were purified with SMISPE and analyzed by LC-MS/MS in positive ionization mode. The results showed that the VCM and NVCM had a good linear correlation in the range of 0.5 µg/kg to 50 µg/kg. The recoveries of target analytes were from 83.3% to 92.1%, and the limits of quantification were both 1.0 µg/kg. The matrix effects of VCM and NVCM were -11.0% and -3.43%, respectively. The proposed method can efficiently eliminate the interference from matrix compounds and reduce baseline noise, which is useful for the monitoring of the residues of VCM and NVCM in milk samples.


Assuntos
Impressão Molecular , Espectrometria de Massas em Tandem , Animais , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Leite , Extração em Fase Sólida , Vancomicina/análogos & derivados
7.
J Hazard Mater ; 421: 126753, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34365237

RESUMO

For the first time, a novel nanocomposite, zeolitic imidazolate framework/magnetic layered double hydroxide (Fe3O4@LDH/ZIF), was successfully fabricated through in situ synthetic method with Fe3O4 as magnetic core and composite as shell. The resulting materials were characterized by XRD, TEM, FT-IR, VSM, TGA and nitrogen adsorption-desorption analysis. The Fe3O4@LDH/ZIF was employed as a sorbent in dispersive micro-solid phase extraction (D-µ-SPE) for enrichment of four endocrine disrupting compounds (EDCs) from milk samples prior to ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) analysis. The synthesized nanocomposite showed bigger specific surface area and better absorption capacity than Fe3O4@LDH. The equilibrium adsorption capacities (Qe, mg/g) of EDCs on the Fe3O4@LDH/ZIF reached up to 47.4-138.8 mg/g, mainly resulting from hydrogen bonding, π-π interaction and electrostatic interaction between EDCs and nanocomposite. Several variables affecting the extraction efficiency were investigated and optimized. The method displays low limits of detection (3-15 ng L-1), good linearity (10-5000 ng L-1), acceptable precision (RSD < 7.8%) and accuracy (RE < 5.2%). Satisfactory repeatability was obtained with RSD in the range of 1.2-7.8%. This work provides a promising approach for the development of new sorbent media in sample preparation for the improvement of analytical performance.


Assuntos
Nanocompostos , Zeolitas , Adsorção , Animais , Cromatografia Líquida de Alta Pressão , Hidróxidos , Limite de Detecção , Fenômenos Magnéticos , Leite , Extração em Fase Sólida , Espectroscopia de Infravermelho com Transformada de Fourier , Espectrometria de Massas em Tandem
8.
Food Chem ; 368: 130820, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34416488

RESUMO

Two commercially available food grade fungal protease preparations (Fungal Protease 31,000 and Fungal Protease 60000) were found to hydrolyse bovine acid whey proteins but left the beta-lactoglobulin (ß-Lg) intact under the processing conditions used. Comparative analysis before and after hydrolysis of bovine acid whey, by 1D- and 2D-PAGE, RP-HPLC and intact-mass mass spectrometry showed that the ß-Lg remains intact and in high yield after hydrolysis by the fungal proteases. The ß-Lg could be separated from the whey protein peptide hydrolysate by ultrafiltration. Subjecting whey fraction to hydrolysis with the fungal protease preparations provides a procedure, under relatively mild conditions, to generate a highly enriched ß-Lg fraction. ß-Lg is recognised as a valued material in the food, pharmaceutical and cosmetic industries due to its properties such as gelling and foaming. The enriched ß-Lg preparation would also have application in areas such as nanoencapsulation.


Assuntos
Lactoglobulinas , Leite , Animais , Bovinos , Hidrólise , Proteínas do Leite , Peptídeo Hidrolases , Soro do Leite , Proteínas do Soro do Leite
9.
Food Chem ; 368: 130866, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34438178

RESUMO

The objective of this work was to investigate the effect of fermentation conditions on c9,t11-conjugated linoleic acid (CLA) synthesized by Lactobacillus casei and the variation of physicochemical characteristics, including pH, viable cell number, syneresis and texture profile, of fermented soy milk (FSM) during storage at 4 °C for 28 days. Fermentation in 7°Brix of soy milk (SM) supplemented with 0.1% linoleic acid and incubated at 37 °C for 72 h was found to be the optimal conditions for c9,t11-CLA biosynthesis. Within the storage of 14 days, viable cell number, total flavonoid content, water-holding capacity, spontaneous syneresis and texture profile in FSM remained stable. During the storage of 28 days, the viable cell number and c9,t11-CLA level were higher than 6.58 log CFU/mL and 816.33 µg/g, respectively.


Assuntos
Ácidos Linoleicos Conjugados , Leite de Soja , Animais , Suplementos Nutricionais , Ácido Linoleico , Leite
10.
Food Chem ; 366: 130648, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34325245

RESUMO

A novel label-free fluorescence aptasensor was established for chloramphenicol (CAP) detection by DNA four-arm junction-assisted target recycling and SYBR Green I dye-aided fluorescence-signal amplification. The CAP aptamer was hybridized to its complementary strand (primer) to form a double-stranded primer/aptamer complex. In the presence of CAP, aptamers can specifically bind with CAP to dissociate primers, which can trigger the self-assembly of four hairpins to continuously generate DNA four-arm junctions. After digesting the excess hairpins using T7 exonuclease, SYBR Green I was inserted into the base pair-rich DNA four-arm junctions, which led to a significant increase in fluorescence intensity. Under optimal conditions, the developed aptasensor can detect CAP in a linear range of 1.0 pg mL-1 to 10 ng mL-1 with a detection limit of 0.72 pg mL-1. The recovery rates in milk and honey ranged from 90.3% to 106.6%. Thus, the method shows substantial potential for CAP detection in food products.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Animais , Cloranfenicol/análise , DNA , Limite de Detecção , Leite/química
11.
Food Chem ; 367: 130700, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34352694

RESUMO

Present study prepared curcumin-loaded nanoliposomes using bovine milk, krill phospholipids and cholesterol; and investigated the effects of cholesterol on membrane characteristics, storage stability and antibacterial properties of the curcumin nanoliposomes. Bovine milk phospholipids which have higher saturation than krill phospholipids resulted in formation of curcumin-loaded nanoliposomes with higher encapsulation efficiency (84.78%), larger absolute value of zeta potential and vesicle size (size: 159.15 ± 5.27 nm, zeta potential: -28.3 ± 0.62 mV). Cholesterol helps to formation of a more hydrophobic, compact and tighter bilayer membrane structure which improved the storage stability of nanoliposomes under alkaline (66.25 ± 0.46%), heat (43.25 ± 0.69%) and sunlight (49.44 ± 1.78%) conditions. In addition, curcumin-loaded nanoliposomes can effectively target infectious bacteria which secrete pore-forming toxins such as Staphylococcus aureus by causing the bacterial cell wall to lysis. Findings from present work can guide future development of novel antibacterial agents for use in food preservation.


Assuntos
Curcumina , Fosfolipídeos , Animais , Antibacterianos , Bovinos , Colesterol , Lipossomos , Leite , Tamanho da Partícula
12.
Food Chem ; 367: 130763, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34384984

RESUMO

Developing highly sensitive and visual methods for rapid detection of antibiotics is significant to ensure food quality and safety. To meet the requirement of nitrofuran antibiotics detection, luminescent fusiform Al(III)-containing metal-organic frameworks (Al-MOF) nanosheets were successfully synthesized by one-step hydrothermal method. And then, the nanosheet served as a fluorescent probe to detect nitrofuran via the inner-filter effect mechanism. The developed sensor allowed sensitive and selective detection of nitrofuran with good linear relationships. And, the detection limit (LOD) values were estimated to be 0.53, 0.838 and 0.583 µM for nitrofurazone, nitrofurantoin and furazolidone detection, respectively. The practical application of the proposed system was verified by HPLC in spiked milk samples with satisfying recoveries ranging from 88.14 to 126.21% and low relative standard deviations of 2.85 ~ 8.13%. Moreover, we designed fluorescent test papers for semi-quantitative detection of nitrofuran via naked-eye colorimetric assay. The established method provides an alternative strategy for semiquantitative detection of nitrofuran.


Assuntos
Estruturas Metalorgânicas , Nitrofuranos , Animais , Antibacterianos/análise , Corantes Fluorescentes , Leite/química , Nitrofuranos/análise
13.
Food Chem ; 371: 131127, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34649198

RESUMO

Several gold platforms of different morphologies were investigated in the elaboration of a new aptasensor for oxytetracycline. Au-nanostructures were electrochemically synthesized from solutions of different concentrations of HAuCl4 in different media by chronoamperometry, multipulse amperometry, and chronopotentiometry, respectively at carbon-based screen-printed electrodes (C-SPE). The nano-/micro-scale morphologies of the patterned surfaces and elemental composition were examined by scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy, respectively. The electrochemical properties of the obtained gold nanostructured platforms (AuNSs|C-SPE) were investigated to achieve optimal aptamer coverage. The results showed that the aptasensor developed using the platform with thistle-like AuNSs exhibited the highest conductivity in terms of ferrocene signal and the largest effective area. Under optimal conditions, a linear range from 5.0 × 10-8 M to 1.2 × 10-6 M, with a limit of detection (LOD) of 8.7 × 10-9 M OXT were obtained, which is about 20 times lower than the EU regulations for OXT residues in milk. The electrochemical aptasensor was able to discriminate other antibacterial agents, such as amoxicillin, ampicillin, gentamicin, tetracycline, and vancomycin and was successfully applied in milk samples. This "signal-on" aptasensing approach provides a simple and cost-effective disposable sensor that could be easily applied for the on-site determination of antibiotics.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Nanopartículas Metálicas , Nanoestruturas , Oxitetraciclina , Animais , Técnicas Eletroquímicas , Eletrodos , Ouro , Limite de Detecção , Leite/química , Oxitetraciclina/análise
14.
Int J Food Microbiol ; 361: 109446, 2022 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-34742146

RESUMO

Clostridium perfringens is one of the most important foodborne pathogens in developed countries. It causes severe food poisoning outbreaks worldwide, along with mortality and economic losses. Recently, bacteriophages have been investigated as an alternative tool to control pathogenic bacteria in the food industry. In this study, 19 Clostridium perfringens and 6 Clostridium perfringens bacteriophages were isolated from chicken meat. According to host range and stability tests, bacteriophage CPQ1 showed high thermostability and the broadest host range. The electron micrograph image of this bacteriophage suggested that it belongs to the Picovirinae subfamily of the Podoviridae family. Nucleotide sequence analysis of the genomic DNA indicated the absence of any antibiotic resistance, toxin, or virulence genes. In broth, CPQ1 showed strong lytic activity with a low MOI of 1, decreasing the OD600 of Clostridium perfringens cell suspension from 0.2 to 0.02 at 37 °C in 2 h. In pasteurized milk and chicken meat, CPQ1 with an MOI of 10 also caused a significant decrease in viable counts of Clostridium perfringens compared to the bacteriophageless control at both 24 °C and 37 °C. This is the first report on the application of bacteriophage to control Clostridium perfringens in foods.


Assuntos
Bacteriófagos , Clostridium perfringens , Animais , Bacteriófagos/genética , Galinhas , Carne , Leite
15.
Parasitol Int ; 86: 102476, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34610467

RESUMO

Trypanosoma theileri is considered a non- or low-pathogenic trypanosome that generally causes latent infection in apparently healthy cattle; however, T. theileri propagates in the bloodstream and may cause clinical disease in pregnant animals or co-infection with bovine leukemia virus or Theileria orientalis. In the current study, a monthly survey of T. theileri infection over one year was carried out in a research dairy farm in Hokkaido, Japan to determine the 1) seasonal variations in the prevalence, 2) genetic characterization of T. theileri, and 3) associations of milk and blood parameters in dairy cattle with T. theileri infection, including data of metabolic profile tests and dairy herd performance tests, using linear mixed models. We found that 1) the prevalence of T. theileri infection was significantly higher in summer and winter than in other seasons; 2) T. theileri possibly showed genetic diversity in Eastern Hokkaido; and 3) T. theileri infection was associated with significantly lower levels of blood urea nitrogen, milk protein, and solids-not-fat, which are caused by a low rumen fermentation level. This is the first study to report the negative impact of T. theileri infection in dairy cattle, and our study indicates that control of T. theileri infection can improve the productivity of dairy cattle.


Assuntos
Doenças dos Bovinos/epidemiologia , Indústria de Laticínios/economia , Variação Genética , Trypanosoma/fisiologia , Tripanossomíase/veterinária , Animais , Sangue/parasitologia , Bovinos , Doenças dos Bovinos/parasitologia , Japão/epidemiologia , Leite/parasitologia , Estações do Ano , Trypanosoma/genética , Tripanossomíase/epidemiologia , Tripanossomíase/parasitologia
16.
Spectrochim Acta A Mol Biomol Spectrosc ; 264: 120324, 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-34481254

RESUMO

A hybrid fluorescent sensing probe was developed and used to quantitatively analyse thiamphenicol. The probe was constructed by entrapping mesoporous carbon and CdTe*CdS*ZnS quantum dots in molecularly imprinted polymer. The probe was characterized, and the construction and detection conditions were optimized. In the optimized conditions, the recognition sites of the nanoprobe were ultrasensitive and highly selective toward thiamphenicol. The quantitative analysis of thiamphenicol was based on the fluorescence quenching of the hybrid nanoprobe by thiamphenicol. Fluorescence emission was quenched linearly from 0.10 to 100 µg L-1 with a coefficient of determination (R2) of 0.9979. The limit of detection was 0.04 µg L-1. The accuracy of an optosensor based on the hybrid probe was evaluated by analyzing spiked milk samples. The results obtained were compared with the results of high-performance liquid chromatography (HPLC) analysis. The quantitative analysis of the spiked samples with the optosensor agreed well with HPLC analysis. Recoveries were in the range of 93.5 to 100.1 % with good precision (RSD < 5%). The accuracy, speed and convenience of the developed optosensor make it a powerful tool for the detection of thiamphenicol in milk.


Assuntos
Compostos de Cádmio , Impressão Molecular , Pontos Quânticos , Tianfenicol , Animais , Carbono , Limite de Detecção , Leite , Polímeros , Telúrio
17.
Food Chem ; 369: 130957, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34488134

RESUMO

This study elaborated different probiotic goat milk yogurt formulations with addition of a low-calorie Isabel "Precoce" grape preparation and flour from derived solid by-products. Physicochemical characteristics, probiotic counts, phenolic and protein/peptide molecular weight profile, antioxidant capacity (AC) and sensory acceptance of different yogurt formulations were evaluated. Yogurts with Isabel grape ingredients (IGI) had high nutritional value, distinct phenolic profile and high AC. High counts of probiotic Lactobacillus acidophilus La-05 were found in yogurts during storage. AC of yogurts with IGI increased during a simulated gastrointestinal digestion with breakdown of high molecular weight proteins and release of protein-bound phenolics. AC of yogurts with IGI should be linked to goat milk peptides and Isabel grape phenolics. Yogurts with IGI had enhanced sensory acceptance. Incorporation of Isabel grape preparation and derived by-product flour into probiotic goat milk yogurt resulted in an added-value product with multifunctional characteristics and improved sensory characteristics.


Assuntos
Probióticos , Vitis , Animais , Cabras , Leite , Iogurte
18.
Food Chem ; 370: 131312, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34788957

RESUMO

A rapid and sensitive hybrid nanosensor was reported with a colorimetric and fluorometric readout system using graphene quantum dots (GQDs) and gold nanoparticles (AuNPs) for the detection of gentamicin (GENTA) in milk and egg samples. In the presence of AuNPs, the fluorescence (FL) intensity of GQDs gradually decreased due to the inner filter effect (IFE) of AuNPs on the FL intensity of GQDs. In addition of GENTA into AuNPs, AuNPs get aggregated and changed their color from red to blue, due to which the IFE of AuNPs reduced and hence, enhanced FL intensity of GQDs with varying concentration of GENTA from 1.03 to 16.55 µM with a lower detection limit of 0.422 µM and 0.493 µM in colorimetric and fluorimetric systems, respectively. The practical application of the developed nanosensor is tested against the real spiked sample. The excellent and straightforward recovery efficiency of the developed nanosensor for the determination of GENTA and can be used as a promising and adaptable tool for speedy monitoring of food quantity.


Assuntos
Grafite , Nanopartículas Metálicas , Pontos Quânticos , Animais , Gentamicinas , Ouro , Limite de Detecção , Leite
19.
Food Chem ; 370: 131057, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34536781

RESUMO

Advances in Matrix-assisted Laser Desorption/Ionization -Time-Of-Flight Mass Spectrometry (MALDI-TOF-MS) have led to its supremacy for complex assessment of food authenticity studies, like dairy products fraud, holding promise for the discovery of potential authenticity (bio)markers. In this study, an integrated untargeted protein-based workflow in combination with advanced chemometrics is presented, to address authenticity challenges in PDO feta cheese which is legally manufactured by the mixture of sheep/goat milk. Potential markers attributed to specific animal origin were found from protein profiles acquired for authentic feta and white cheeses (prepared from cow milk), belonging to 4 kDa-18.5 kDa mass area. Rapid detection of feta cheese adulteration from cow milk was also achieved down to 1% adulteration level. The discriminative models showed high predictive ability for feta cheese authenticity (Q2 = 0.920, RMSEE = 0.053) and its adulteration (Q2 = 0.835, RMSEE = 0.121), introducing a reliable approach in routine analysis. The methodology was successfully applied in detection of cow milk in sheep yoghurt.


Assuntos
Queijo , Animais , Bovinos , Queijo/análise , Feminino , Contaminação de Alimentos/análise , Leite , Ovinos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Fluxo de Trabalho
20.
Food Chem ; 370: 131027, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34537432

RESUMO

The pollution caused by estrogens in the environment and food has received increasing attention. It is still challenging for on-site immunochromatographic assay (ICA) detection of estrogens. The performance of the prepared probes plays a decisive role in the sensitivity and stability of the ICA system. The published probes usually directly couple the detection antibody to the label, ignoring the influence of the label on the activity of the antibody. In this study, 17ß-estradiol (E2) was used as a model analyte for the ICA system. Two universal probes were constructed based on quantum dot nanobeads (QBs), recombinant protein A (SPA, from Staphylococcus aureus), and rabbit anti-mouse immunoglobulin G antibody (anti-IgG). The probes were prepared by coupling QBs with SPA, releasing anti-E2 monoclonal antibody (mAb), and maintaining its activity. The prepared universal probes can orient recognize the Fc region of mAb and fully expose its Fab region, improving the detection sensitivity of the ICA system. The free anti-E2 mAb and the universal probe (QBs@SPA or QBs@SPA@anti-IgG) were used as the detection antibodies and signal donors, respectively. The results show that the proposed ICA based on QBs@SPA and QBs@SPA@anti-IgG probes could detect E2 with IC50 of 8.83 and 0.93 ng/mL, respectively, within 15 min under optimal conditions. The recovery results of ICA based on QBs@SPA and QBs@SPA@anti-IgG probes showed good agreement with the findings of the high-performance liquid chromatography (HPLC) analysis for spiked samples. The developed ICA system based on universal probes was superior in terms of sensitivity, rapidity, and applicability, and held great promise for its implementation in detecting environmental and food small-molecule pollutants.


Assuntos
Leite , Pontos Quânticos , Animais , Anticorpos , Estradiol , Imunoensaio , Camundongos , Coelhos
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