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1.
Anal Chim Acta ; 1178: 338802, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34482881

RESUMO

Dispersive micro solid-phase extraction procedure using a novel and selective sorbent prepared from four components was developed as a sample preparation strategy for extracting five organophosphorus pesticides, including fenitrothion, malathion, ethion, and chlorpyrifos, and diazinon in several vegetables, fruit juices, and cow's milk samples. Due to the high importance of the sorbent in the microextraction process, the percentages of sorbent components, including metal-organic framework (ZIF-67), chitosan, magnetic Fe3O4 nanoparticles, and silica nanoparticles, were optimized by a simplex lattice mixture design. After optimizing the sorbent composite, effective parameters on the extraction of organophosphorus pesticides were optimized using a definitive screening design and Box-Behnken design, respectively. A surfactant (Triton X100) as a dispersion agent with a low volume (10 µL) was utilized in the microextraction procedure to reduce the sorbent dispersion time and increase the sorbent dispersion efficiency. Under the optimal conditions, linearity for the determination of fenitrothion, malathion, ethion, chlorpyrifos, and diazinon was in the concentration ranges of 0.13-1100, 0.27-1000, 0.38-1000, 0.21-1200, and 0.11-1100 ng mL-1 with a determination coefficient higher than 0.9906, respectively. The quantitation limits, detection limits, and relative standard deviations (n = 5) were lower than 0.38 ng mL-1, 0.11 ng mL-1, and 4.59% for the determination of organophosphorus pesticides. The method application for measuring OPPs on cucumber, carrot, tomato, apple juice, orange juice, and cow's milk indicated the presence of residual amounts of malathion in a cucumber sample, diazinon in a carrot sample, and chlorpyrifos in a tomato sample.


Assuntos
Resíduos de Praguicidas , Praguicidas , Animais , Sucos de Frutas e Vegetais , Limite de Detecção , Fenômenos Magnéticos , Leite/química , Compostos Organofosforados/análise , Praguicidas/análise , Extração em Fase Sólida , Verduras , Água/análise
2.
Talanta ; 235: 122779, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517637

RESUMO

To ensure the safety of dairy products, especially milk, and consequently protect human health, accurate and simple analytical techniques are highly necessary to determine the low concentration of aflatoxin M1 (AFM1) as an important carcinogen. Herein, a novel, accurate and simple fluorescent aptasensor was designed for selective detection of AFM1 based on bivalent binding aptamer-cDNA (BBA-cDNA) structure. Moreover, MoS2 nanosheets (MoS2 NSs) were used as the fluorescent quencher and FAM-labeled complementary strand of aptamer (FAM-CS) was applied as a fluorescent probe. In this study, we achieved a new result. Unlike previous studies, in this work, the BBA-cDNA structure was not disassembled in the presence of the target. Therefore, as the AFM1 concentration increased, more targets were attached to the BBA-cDNA structure and as a result, the BBA-cDNA structure/AFM1 could not be placed on the surface of MoS2 NSs, leading to the more fluorescent intensity detection. Under optimized conditions, the developed fluorescent analytical method revealed great selectivity toward AFM1 with a limit of detection (LOD) of 0.5 nM and a linear range from 0.7 to 10 nM. This fabricated aptasensor indicated excellent analytical performance for AFM1 detection in milk samples with LOD of 0.1 nM. Overall, the proposed approach could provide an effective basis for small molecule analysis to guarantee food and human safety using appropriate aptamer sequences.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Aflatoxina M1/análise , Animais , DNA Complementar , Humanos , Limite de Detecção , Leite/química , Molibdênio
3.
Am J Physiol Cell Physiol ; 321(3): C607-C614, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34378992

RESUMO

Bovine milk exosomes (BMEs) are being explored in drug delivery despite their rapid elimination by macrophages. We aimed at identifying the BME transporter in murine bone marrow-derived macrophages (BMDMs). Fluorophore-labeled BMEs were used in transport studies in BMDMs from C57BL/6J and class A scavenger receptor type 1/2 (CASR-1/2) knockout mice and tissue accumulation in macrophage-depleted C57BL/6J mice. Parametric and nonparametric statistics tests for pairwise and multiple comparisons were used. Chemical inhibitors of phagocytosis by cytochalasin D led to a 69 ± 18% decrease in BME uptake compared with controls (P < 0.05), whereas inhibitors of endocytic pathways other than phagocytosis had a modest effect on uptake (P > 0.05). Inhibitors of class A scavenger receptors (CASRs) including CASR-1/2 caused a 70% decrease in BME uptake (P < 0.05). The uptake of BMEs by BMDMs from CASR-1/2 knockout mice was smaller by 58 ± 23% compared with wild-type controls (P < 0.05). Macrophage depletion by clodronate caused a more than 44% decrease in BME uptake in the spleen and lungs (P < 0.05), whereas the decrease observed in liver was not statistically significant. In conclusion, CASR-1/2 facilitates the uptake of BMEs in BMDMs and C57BL/6J mice.


Assuntos
Exossomos/metabolismo , Macrófagos/metabolismo , Leite/química , Receptores Depuradores Classe A/genética , Animais , Bovinos , Ácido Clodrônico/farmacologia , Citocalasina D/farmacologia , Endocitose/efeitos dos fármacos , Exossomos/química , Feminino , Corantes Fluorescentes/química , Expressão Gênica , Fígado/efeitos dos fármacos , Fígado/metabolismo , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fagocitose/efeitos dos fármacos , Isoformas de Proteínas/deficiência , Isoformas de Proteínas/genética , Receptores Depuradores Classe A/deficiência , Baço/efeitos dos fármacos , Baço/metabolismo , Coloração e Rotulagem/métodos
4.
Molecules ; 26(16)2021 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-34443568

RESUMO

Laser-Induced Breakdown Spectroscopy (LIBS), having reached a level of maturity during the last few years, is generally considered as a very powerful and efficient analytical tool, and it has been proposed for a broad range of applications, extending from space exploration down to terrestrial applications, from cultural heritage to food science and security. Over the last decade, there has been a rapidly growing sub-field concerning the application of LIBS for food analysis, safety, and security, which along with the implementation of machine learning and chemometric algorithms opens new perspectives and possibilities. The present review intends to provide a short overview of the current state-of-the-art research activities concerning the application of LIBS for the analysis of foodstuffs, with the emphasis given to olive oil, honey, and milk.


Assuntos
Produtos Biológicos/química , Análise de Alimentos/métodos , Mel/análise , Lasers , Leite/química , Azeite de Oliva/química , Análise Espectral , Animais
5.
Molecules ; 26(15)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34361753

RESUMO

The popularity and consumption of fermented milk products are growing. On the other hand, consumers are interested in health-promoting and functional foods. Fermented milk products are an excellent matrix for the incorporation of bioactive ingredients, making them functional foods. To overcome the instability or low solubility of many bioactive ingredients under various environmental conditions, the encapsulation approach was developed. This review analyzes the fortification of three fermented milk products, i.e., yogurt, cheese, and kefir with bioactive ingredients. The encapsulation methods and techniques alongside the encapsulant materials for carotenoids, phenolic compounds, omega-3, probiotics, and other micronutrients are discussed. The effect of encapsulation on the properties of bioactive ingredients themselves and on textural and sensory properties of fermented milk products is also presented.


Assuntos
Queijo/análise , Tecnologia de Alimentos/métodos , Alimento Funcional/análise , Kefir/análise , Leite/metabolismo , Iogurte/análise , Animais , Carotenoides/administração & dosagem , Carotenoides/química , Ácidos Graxos Ômega-3/administração & dosagem , Fermentação , Aditivos Alimentares/administração & dosagem , Humanos , Lactobacillaceae/fisiologia , Micronutrientes/administração & dosagem , Leite/química , Leite/microbiologia , Fenóis/administração & dosagem , Fenóis/química , Probióticos/administração & dosagem
6.
Animal ; 15(9): 100311, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34416555

RESUMO

Accurate and precise estimates of nitrogen (N) excretion in faeces and urine of dairy cattle may provide direct tools to improve N management and thus, to mitigate environmental pollution from dairy production. Empirical equations of N excretion have been evaluated for indoor dairy cattle but there is no evaluation for cows fed high proportions of fresh forage. Therefore, the objective of the current study was to evaluate N excretion equations with a unique data set of zero-grazing experiments. Through literature searches, 89 predictive equations were identified from 13 studies. An independent data set was developed from seven zero-grazing experiments with, in total, 55 dairy Holstein-Friesian cows. Models' performance was evaluated with statistics derived from a mixed-effect model and a simple regression analysis model. Squared sample correlation coefficients were used as indicators of precision and based on either the best linear unbiased predictions (R2BLUP) or model-predicted estimates (R2MDP) derived from the mixed model and simple regression analysis, respectively. The slope (ß0), the intercept (ß1) and the root mean square prediction error (RMSPEm%) were calculated with the mixed-effect model and used to assess accuracy. The root mean square prediction error (RMSPEsr%) and the decomposition of the mean square prediction error were calculated with the simple regression analysis and were used to estimate the error due to central tendency (mean bias), regression (systematic bias), and random variation. Concordance correlation coefficient (CCC) were also calculated with the simple regression analysis model and were used to simultaneously assess accuracy and precision. Considering both analysis models, results suggested that urinary N excretion (UN; R2MDP = 0.76, R2BLUP = 0.89, RMSPEm% = 17.2, CCC = 0.82), total manure N excretion (ManN; R2MDP = 0.83, R2BLUP = 0.90, RMSPEm% = 11.0, CCC = 0.84) and N apparently digested (NAD; R2MDP = 0.97, R2BLUP = 0.97, RMSPEm% = 5.3, CCC = 0.95) were closely related to N intake. Milk N secretion was better predicted using milk yield as a single independent variable (MilkN; R2MDP = 0.77, R2BLUP = 0.97, RMSPEm% = 6.0, CCC = 0.74). Additionally, DM intake was a good predictor of UN and ManN and dietary CP concentration of UN and ManN. Consequently, results suggest that several evaluated empirical equations can be used to make accurate and precise predictions concerning N excretion from dairy cows being fed on fresh forage.


Assuntos
Lolium , Animais , Bovinos , Dieta/veterinária , Lactação , Leite/química , Nitrogênio/análise
7.
Nutrients ; 13(8)2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34444905

RESUMO

Gamma-amino butyric acid (GABA) is marketed in the U.S. as a dietary supplement. USP conducted a comprehensive safety evaluation of GABA by assessing clinical studies, adverse event information, and toxicology data. Clinical studies investigated the effect of pure GABA as a dietary supplement or as a natural constituent of fermented milk or soy matrices. Data showed no serious adverse events associated with GABA at intakes up to 18 g/d for 4 days and in longer studies at intakes of 120 mg/d for 12 weeks. Some studies showed that GABA was associated with a transient and moderate drop in blood pressure (<10% change). No studies were available on effects of GABA during pregnancy and lactation, and no case reports or spontaneous adverse events associated with GABA were found. Chronic administration of GABA to rats and dogs at doses up to 1 g/kg/day showed no signs of toxicity. Because some studies showed that GABA was associated with decreases in blood pressure, it is conceivable that concurrent use of GABA with anti-hypertensive medications could increase risk of hypotension. Caution is advised for pregnant and lactating women since GABA can affect neurotransmitters and the endocrine system, i.e., increases in growth hormone and prolactin levels.


Assuntos
Anti-Hipertensivos/uso terapêutico , Suplementos Nutricionais , Substâncias para Melhoria do Desempenho/uso terapêutico , Vigilância de Produtos Comercializados , Ácido gama-Aminobutírico/uso terapêutico , Animais , Pressão Sanguínea/efeitos dos fármacos , Cães , Feminino , Fermentação , Humanos , Masculino , Leite/química , Gravidez , Ratos , Alimentos de Soja/análise , Estados Unidos
8.
Molecules ; 26(16)2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34443426

RESUMO

Proteomics and metabolomics are analytic tools used in combination with bioinformatics to study proteins and metabolites which contribute to describing complex biological systems. The growing interest in research concerning the resolution of these systems has stimulated the development of sophisticated procedures and new applications. This paper introduces the evolution of statistical techniques for the treatment of data, suggesting the possibility to successfully characterize the milk-whey syneresis process by applying two-dimensional correlation analysis (2DCOR) to a series of CE electropherograms referring to milk-whey samples collected during cheese manufacturing. Two cheese-making processes to produce hard cheese (Grana type) and fresh cheese (Crescenza) were taken as models. The applied chemometric tools were shown to be useful for the treatment of data acquired in a systematically perturbed chemical system as a function of time.


Assuntos
Ácidos/análise , Queijo/análise , Leite/química , Nitrogênio/análise , Soro do Leite/química , Animais , Eletroforese Capilar , Projetos Piloto
9.
Molecules ; 26(15)2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-34361782

RESUMO

Thermal treatments of milk induce changes in the properties of milk whey proteins. The aim of this study was to investigate the specific changes related to nutrients in the whey proteins of dairy cow milk after pasteurization at 85 °C for 15 s or ultra-high temperature (UHT) at 135 °C for 15 s. A total of 223 whey proteins were confidently identified and quantified by TMT-based global discovery proteomics in this study. We found that UHT thermal treatment resulted in an increased abundance of 17 proteins, which appeared to show heat insensitivity. In contrast, 15 heat-sensitive proteins were decreased in abundance after UHT thermal treatment. Some of the heat-sensitive proteins were connected with the biological immune functionality, suggesting that UHT thermal treatment results in a partial loss of immune function in the whey proteins of dairy cow milk. The information reported here will considerably expand our knowledge about the degree of heat sensitivity in the whey proteins of dairy cow milk in response to different thermal treatments and offer a knowledge-based reference to aid in choosing dairy products. It is worth noting that the whey proteins (lactoperoxidase and lactoperoxidase) in milk that were significantly decreased by high heat treatment in a previous study (142 °C) showed no significant difference in the present study (135 °C). These results may imply that an appropriately reduced heating intensity of UHT retains the immunoactive proteins to the maximum extent possible.


Assuntos
Leite/química , Pasteurização/métodos , Proteínas do Soro do Leite/química , Soro do Leite/química , Animais , Feminino , Temperatura Alta , Leite/imunologia , Anotação de Sequência Molecular , Estabilidade Proteica , Proteômica/métodos , Soro do Leite/imunologia , Proteínas do Soro do Leite/classificação , Proteínas do Soro do Leite/imunologia , Proteínas do Soro do Leite/isolamento & purificação
10.
Molecules ; 26(15)2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-34361798

RESUMO

A fast HPLC method with fluorescence detector (FD) was developed for the determination of three tocopherols (TOCs) in milk samples from Modicana cattle breed. The ultrasound-assisted procedure was optimized for the extraction of TOCs prior to HPLC/FD analysis, reducing sample preparation time and allowing a fast quantification of α-tocopherol, δ-tocopherol and γ tocopherol. The optimized ultrasonic extraction combines an efficient and simple saponification at room temperature and a rapid HPLC quantification of TOCs in milk. The precision of the full analytical procedure was satisfactory and the recoveries at three spiked levels were between 95.3% and 87.8%. The linear correlations were evaluated (R2 > 0.99) and the relative standard deviation (RSD) values for intra-day and inter-day tests at three spiked levels were below 1% for the retention time and below 5.20% for the area at low level spiking. The proposed procedure, reducing the experimental complexity, allowed accurate extraction and detection of three TOCs in milk samples from Modicana cattle breed.


Assuntos
Cromatografia Líquida de Alta Pressão/normas , Extração Líquido-Líquido/métodos , Leite/química , Tocoferóis/isolamento & purificação , alfa-Tocoferol/isolamento & purificação , gama-Tocoferol/isolamento & purificação , Animais , Bovinos , Limite de Detecção , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Saponinas/química , Sonicação , Fatores de Tempo
11.
Environ Monit Assess ; 193(7): 456, 2021 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-34213650

RESUMO

Aflatoxins, produced by multiple fungal species, are present in several kinds of food items and animal feed. Several studies conducted in Pakistan have reported the presence of aflatoxin M1 (AFM1) in milk. Hence, owing to the public health concern and absence of general statistics regarding the prevalence of AFM1 contamination, current study was aimed to investigate the prevalence of AFM1 in milk in Pakistan. For this study, various databases were searched from 2007 to 2020. A random effect model was applied for analytical purpose and heterogeneity of selected studies was investigated with an I2 index. Comprehensive meta-analysis (version 3) was used for analysis of data. According to the results, prevalence of AFM1 in milk was 84.4% (95% CI 75.0-90.7%). Regarding the heterogeneity based on meta-regression, it has been observed that there was a significant difference between the effect of year of study and sample size with prevalence of AFM1 in animal milk. These results suggest that AFM1 contamination in animal milk is high in Pakistan. Hence, continuous monitoring of AFM1 in animal milk requires utmost attention from the respective food and drug regulatory authorities of Pakistan so that the strict actions and preventive measures should be taken to prevent the prevalence of exposure of AFM1 in animal milk.


Assuntos
Aflatoxina M1 , Leite , Aflatoxina M1/análise , Animais , Monitoramento Ambiental , Contaminação de Alimentos/análise , Leite/química , Paquistão , Prevalência , Estudos Retrospectivos
12.
Nutrients ; 13(6)2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34203636

RESUMO

BACKGROUND: beta-lactoglobulin (BLG) is one of the major cow's milk proteins and the most abundant allergen in whey. Heating is a common technologic treatment applied during milk transformational processes. Maillardation of BLG in the presence of reducing sugars and elevated temperatures may influence its antigenicity and allergenicity. PRIMARY OBJECTIVE: to analyze and identify lactosylation sites by capillary electrophoresis mass spectrometry (CE-MS). SECONDARY OBJECTIVE: to assess the effect of lactosylated BLG on antigenicity and degranulation of mast cells. METHODS: BLG was lactosylated at pH 7, a water activity (aw) of 0.43, and a temperature of 65 °C using a molar ratio BLG:lactose of 1:1 by incubating for 0, 3, 8, 16 or 24 h. For the determination of the effect on antibody-binding capacity of lactosylated BLG, an ELISA was performed. For the assessment of degranulation of the cell-line RBL-hεIa-2B12 transfected with the human α-chain, Fcε receptor type 1 (FcεRI) was used. RESULTS: BLG showed saturated lactosylation between 8 and 16 incubation hours in our experimental setup. Initial stage lactosylation sites L1 (N-terminus)-K47, K60, K75, K77, K91, K138 and K141-have been identified using CE-MS. Lactosylated BLG showed a significant reduction of both the IgG binding (p = 0.0001) as well as degranulation of anti-BLG IgE-sensitized RBL-hεIa-2B12 cells (p < 0.0001). CONCLUSIONS AND CLINICAL RELEVANCE: this study shows that lactosylation of BLG decreases both the antigenicity and degranulation of mast cells and can therefore be a promising approach for reducing allergenicity of cow's milk allergens provided that the process is well-controlled.


Assuntos
Lactoglobulinas/análise , Hipersensibilidade a Leite , Leite/química , Alérgenos/análise , Animais , Bovinos , Feminino , Humanos , Imunoglobulina E/análise , Imunoglobulina G , Lactose/análise , Reação de Maillard , Mastócitos , Proteínas do Leite/análise , Soro do Leite , Proteínas do Soro do Leite/análise
13.
Biomolecules ; 11(7)2021 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-34208895

RESUMO

The aim of this research was phenolics and protein characterization and antioxidant properties evaluation of skimmed thermally treated goat's milk powder enriched with different concentration of grape pomace seed extract (SE). The dominant phenolics in SE were phenolic acids, flavan-3-ols and procyanidins. Different electrophoretic techniques together with UHPLC-MS/MS analysis revealed the presence of phenolics-protein interactions in the samples, mainly procyanidins with whey protein/caseins complexes. Addition of SE into thermally treated goat's milk significantly improved antioxidant properties of goat's milk such as TAC, FRP, DPPH• and ABTS•+ scavenging activity. Gallic acid, catechin, and procyanidins mostly contributed to these activities. The schematic representation of phenolics-casein micelles interactions in thermally treated goat's milk enriched with SE was given. The addition of SE into thermally treated goat's milk can be a promising strategy in food waste recovery and to enhance the beneficial health effects of goat's milk-based functional foods.


Assuntos
Suplementos Nutricionais/análise , Extrato de Sementes de Uva/química , Leite/química , Animais , Caseínas , Flavonoides/análise , Cabras/metabolismo , Hidroxibenzoatos/análise , Extratos Vegetais/química , Pós , Proantocianidinas/análise , Eliminação de Resíduos/métodos , Espectrometria de Massas em Tandem/métodos
14.
Artigo em Inglês | MEDLINE | ID: mdl-34219038

RESUMO

As an active glycoprotein with high nutritional value, lactoferrin is widely used in food and medical treatment. Therefore, it is very important to establish an accurate and efficient detection method for lactoferrin. At present, the detection of lactoferrin in milk faces many challenges, such as low separation degree and poor parallelism. To address this issue, we developed an aptamer affinity column (AAC) for purification and enrichment of lactoferrin in milk. The column was prepared by covalent conjugation of an amino-modified aptamer with NHS-activated Sepharose. The washing buffer type (0.01 mol/L phosphate buffer) and volume (10 mL) and the sodium chlorideconcentration (1 mol/L) in the elution buffer were optimized for the AAC method. The performance of the AAC was then evaluated in terms of the column capacity, specificity, stability, and reusability. The column capacity was 500 ± 13.7 µg and the column could be reused up to ten times with a large loss in performance. The AAC method combined with high-performance liquid chromatography gave excellent linearity over a wide range, good sensitivity with a limit of detection of 3 µg/mL, and acceptable recoveries for different concentrations of lactoferrin spiked in real raw milk samples from cattle. Finally, the AAC was successfully applied to analyze lactoferrin in milk. This method could be applied to routine analysis of samples for lactoferrin in testing laboratories and dairy factories.


Assuntos
Cromatografia de Afinidade/métodos , Lactoferrina , Leite/química , Animais , Aptâmeros de Nucleotídeos/química , Bovinos , Cromatografia Líquida de Alta Pressão/métodos , Lactoferrina/análise , Lactoferrina/química , Lactoferrina/isolamento & purificação , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes
15.
Sci Total Environ ; 794: 148504, 2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-34198078

RESUMO

Polychlorodibenzo-p-dioxins, polychlorodibenzo-furans (PCDD/Fs) and dioxin-like polychlorobiphenyls (DL-PCBs) enter the food chain from the environment. In this study, we report the 2008-2018 time-trends in the PCDD/F and DL-PCB contamination of milk from buffaloes fed on local forage in rural areas of the Campania region. Validated according to QA/QC criteria, the dataset (N = 808 on a total of 2068 samples, after excluding follow-up results and outliers) was computed on the upper-bound value pg WHO-TEQ2005 g-1fat. We assessed time-trends and assayed baseline contamination levels, which displayed log-normal distribution. A significant decreasing trend (p < 0.01) was observed from 2008 to 2009 and 2010; the P50-P95 range fell from 2.37-8.48 pg WHO-TEQ2005 g-1fat (N = 393) in 2008 to 1.73-4.61 in 2009 (N = 86) and to 0.67-1.46 in 2010 (N = 42). From 2010 to 2018 (N = 329), no significant variation was found among years and the related dataset fitted a log-normal distribution (p < 0.05). Occurrence descriptors indicated that the baseline contamination of dairy products (mean = 0.54; P50-P95 = 0.47-1.24) in the Campania Region was well below the EU regulatory limit in force (5.5 pg WHO-TEQ2005 g-1fat). Given the Tolerable Weekly Intake of 2 pg WHO-TEQ kg-1 body weight (bw) proposed by the EFSA for PCDD/Fs and DL-PCBs, this level of baseline contamination is discussed with regard to the orientation of food safety and food security risk connected with buffalo mozzarella cheese production.


Assuntos
Benzofuranos , Dioxinas , Poluentes Ambientais , Bifenilos Policlorados , Dibenzodioxinas Policloradas , Animais , Benzofuranos/análise , Búfalos , Dibenzofuranos , Dibenzofuranos Policlorados , Dioxinas/análise , Poluentes Ambientais/análise , Contaminação de Alimentos/análise , Itália , Leite/química , Bifenilos Policlorados/análise , Dibenzodioxinas Policloradas/análise
16.
Spectrochim Acta A Mol Biomol Spectrosc ; 263: 120160, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34284279

RESUMO

A derivatization and air-assisted dispersive liquid-liquid microextraction procedure with organic phase solidification on a paper template was developed for the first time. The procedure was used for the spectrofluorometric determination of formaldehyde in milk samples. The Hantzsch reaction of formaldehyde with acetylacetone in the presence of ammonia to form a derivative (3,5-diacetyl-1,4-dihydrolutidine) was implemented for the microextraction and detection of analyte. Thymol was investigated as the extraction solvent for the air-assisted dispersive liquid-liquid microextraction for the first time. In the developed procedure, molten thymol was added to the thermostated aqueous sample solution containing reagents for formaldehyde derivatization, and cloudy solution of fine thymol droplets was formed by air bubbling. After separation of phases the liquid extract phase was withdrawn with a dispenser and distributed on the black paper template in a thin layer to be solidified. The solidified extract phase on the template was inserted to a sample holder of a spectrofluorometer and fluorescence intensity was measured without using cuvettes. Under optimal experimental conditions the linear detection range was found to be 45-500 µg L-1 with LOD calculated from a blank test, based on 3σ, 15 µg L-1. The developed procedure does not require the dilution of the solid extract phase in organic solvent to be introduced in an analytical instrumentation and the use of cuvettes for spectrofluorometric detection.


Assuntos
Microextração em Fase Líquida , Leite , Animais , Formaldeído/análise , Leite/química , Solventes , Água
17.
Ultrason Sonochem ; 77: 105668, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34298307

RESUMO

To extend the shelf life and retain bioactive proteins in milk, this study utilized microfiltration (MF) combined with ultrasonication to treat skim milk and investigated its efficiency in removing bacteria and retaining bioactive proteins compared with HTST pasteurization and microfiltration alone. Results showed that microfiltration combined with ultrasonication at 1296 J/mL could completely remove the bacteria in skim milk. Ultrasonication further extended the shelf life (4 °C) of microfiltered skim milk, which could reach at least 40 days when MF was combined with ˃1296 J/mL ultrasonication. In addition, ELISA showed that HTST pasteurization significantly decreased the levels of IgG by ~30%, IgA by ~ 50%, IgM by ~60%, and lactoferrin by ~40%, whereas the activity of the enzymes lactoperoxidase and xanthine oxidase were also decreased by ~ 20%. Compared with HTST, MF alone or combined with ultrasonication retained these bioactive proteins to a larger degree. On the other hand, proteomics indicated both damage to casein micelle and fat globule structures in milk when ultrasonication at >1296 J/mL was applied, as shown by increases in caseins and milk fat globular proteins. Simultaneously, this ultrasound intensity also decreased levels of bioactive proteins, such as complement factors. Taken together, this study provided new insights that may help to implement this novel combination of non-thermal technologies for the dairy industry aimed at improving milk quality and functionality.


Assuntos
Filtração , Armazenamento de Alimentos , Leite/química , Proteínas/química , Sonicação , Animais , Temperatura
18.
Ultrason Sonochem ; 77: 105673, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34311321

RESUMO

The effect of ultrasound treatment on molecular mobility and organization of the main components in raw goat milk was studied by EPR and NMR spectroscopies. NMR relaxation studies showed an increase in the spin-lattice T1 and spin-spin T2 relaxation times in goat milk products (cream, anhydrous fat) and change in the diffusion of proton-containing molecules during ultrasound treatment. The diffusion became more uniform and could be rather accurately approximated by one effective diffusion coefficient Deff, which indicates homogenization of goat milk components, dispersion of globular and supermicellar formations under sonication. EPR studies have shown that molecular mobility and organization of hydrophobic regions in goat milk are similar to those observed in micellar formations of surfactants with a hydrocarbon chain length C12-C16. Ultrasound treatment did not affect submicellar and protein globule organization. Free radicals arising under ultrasound impact of milk reacted quickly with components of goat milk (triglycerides, proteins, fatty acids) and were not observed by spin trapping method.


Assuntos
Espectroscopia de Ressonância de Spin Eletrônica , Cabras , Espectroscopia de Ressonância Magnética , Leite/química , Ondas Ultrassônicas , Animais , Interações Hidrofóbicas e Hidrofílicas
19.
Ecotoxicol Environ Saf ; 222: 112482, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34224969

RESUMO

Herein, a kind of novel multi-layer core-shell nanocomposites (NSPN) was prepared by employing SiO2 and polyvinylpyrrolidone (PVP) polymers as modifiers and amino-functionalized metal-organic frameworks (NH2-MIL101(Fe)) as coating. It was referred to as the NSPN and ILs-based effervescence-assisted dispersive solid-phase microextraction, hereafter abbreviated as NIE-DSM. In terms of extraction efficiency, SiO2 and PVP as modifiers and NH2-MIL(Fe) as coating onto the surface of NiFe2O4 cores played a synergistically enhancing effect on adsorption/extraction. Effervescent tablets were prepared by integrating the NSPN magnetic nanoparticles as adsorbents with imidazolium-based ionic liquids (ILs) as extractants as well as acidic and alkaline sources. Under vigorous dispersion of CO2 bubbles, the NIE-DSM method realized the goal of rapidly diffusing and separating the adsorbent/extractant (~3 min) without needing conventional vortexing or centrifugation step. Consequently, the NIE-DSM approach combined dispersion and adsorption/extractant in a synchronous way. Under optimized conditions, the NIE-DSM/HPLC-FLD method gave low limits of detection (0.008-0.034 µg kg-1) and satisfactory extraction recoveries (74.1-101.6%) for five polycyclic aromatic hydrocarbons (PAHs; fluorene, anthracene, pyrene, chrysene and benzo(a)pyrene) in milk samples. The intra-day and inter-day precision, expressed as relative standard deviations, was < 5.9% and 6.5%, respectively, demonstrating a high precision. Owing to no requirement for electrical power, this method shows great potential for outdoor monitoring of trace-level PAHs in food matrices.


Assuntos
Líquidos Iônicos , Estruturas Metalorgânicas , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Animais , Limite de Detecção , Fenômenos Magnéticos , Leite/química , Hidrocarbonetos Policíclicos Aromáticos/análise , Dióxido de Silício , Extração em Fase Sólida , Comprimidos , Poluentes Químicos da Água/análise
20.
Genet Sel Evol ; 53(1): 62, 2021 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-34284721

RESUMO

BACKGROUND: Fourier-transform mid-infrared (FT-MIR) spectroscopy provides a high-throughput and inexpensive method for predicting milk composition and other novel traits from milk samples. While there have been many genome-wide association studies (GWAS) conducted on FT-MIR predicted traits, there have been few GWAS for individual FT-MIR wavenumbers. Using imputed whole-genome sequence for 38,085 mixed-breed New Zealand dairy cattle, we conducted GWAS on 895 individual FT-MIR wavenumber phenotypes, and assessed the value of these direct phenotypes for identifying candidate causal genes and variants, and improving our understanding of the physico-chemical properties of milk. RESULTS: Separate GWAS conducted for each of 895 individual FT-MIR wavenumber phenotypes, identified 450 1-Mbp genomic regions with significant FT-MIR wavenumber QTL, compared to 246 1-Mbp genomic regions with QTL identified for FT-MIR predicted milk composition traits. Use of mammary RNA-seq data and gene annotation information identified 38 co-localized and co-segregating expression QTL (eQTL), and 31 protein-sequence mutations for FT-MIR wavenumber phenotypes, the latter including a null mutation in the ABO gene that has a potential role in changing milk oligosaccharide profiles. For the candidate causative genes implicated in these analyses, we examined the strength of association between relevant loci and each wavenumber across the mid-infrared spectrum. This revealed shared association patterns for groups of genomically-distant loci, highlighting clusters of loci linked through their biological roles in lactation and their presumed impacts on the chemical composition of milk. CONCLUSIONS: This study demonstrates the utility of FT-MIR wavenumber phenotypes for improving our understanding of milk composition, presenting a larger number of QTL and putative causative genes and variants than found from FT-MIR predicted composition traits. Examining patterns of significance across the mid-infrared spectrum for loci of interest further highlighted commonalities of association, which likely reflects the physico-chemical properties of milk constituents.


Assuntos
Bovinos/genética , Leite/química , Locos de Características Quantitativas , Animais , Estudo de Associação Genômica Ampla , Hibridização Genética , Leite/normas , Oligossacarídeos/análise , Espectroscopia de Infravermelho com Transformada de Fourier
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