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1.
Braz. j. biol ; 84: e258276, 2024. tab, graf, ilus
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1360199

RESUMO

Conjugated Linoleic Acid (CLA) has attracted the attention of many researchers, especially that of microbial origin due to its biological importance to the consumer. The current study aims to extract LA Isomerase enzyme from Lactobacillus paracasei bacteria from milk and to use the enzyme in the production of CLA. Selective media, including MRS and MRS-Dagatose, were used in isolating local strains. The selected bacterial isolates were tested for their ability to produce LA-Isomerase enzyme. The isolate with high enzymatic activity was selected. After extraction and partial purification of the enzyme, the optimal conditions for the production of conjugated fatty acid were studied, and the reaction products were diagnosed using GC-MS technology. It was found that 11 isolates have the ability to produce CLA at different concentrations, H1 isolate showed the highest production of conjugated fatty acid at a concentration of 120.45 g.ml-1, this isolate was selected as the source for enzyme extraction. The enzymatic activity of the crude extract and partially purified with ammonium sulfate was estimated using color methods at wavelength of 233 nm. The effect of the optimum conditions (pH, temperature, linoleic acid concentration and enzyme concentration) on the CLA product was studied using the partially purified LA Isomerase enzyme, the optimum conditions for production were 6.5, 45 °C, 100 µg.ml-1 and 0.7 ml, respectively. The GC-MS technique showed the presence of a number of reaction products that are isomers of conjugated linoleic acid (C9T11, T9T12, T10C12) with different concentrations.


O Ácido Linoleico Conjugado (CLA) tem chamado a atenção de diversos pesquisadores, principalmente aquele de origem microbiana, devido à sua importância biológica para o consumidor. O presente estudo visa extrair a enzima LA Isomerase da bactéria Lactobacillus paracasei do leite e usar essa enzima na produção de CLA. Meios seletivos, incluindo MRS e MRS-Dagatose, foram usados no isolamento de cepas locais. Os isolados bacterianos selecionados foram testados quanto à sua capacidade de produzir a enzima LA-Isomerase. Foi selecionado o isolado com alta atividade enzimática. Após a extração e purificação parcial da enzima, as condições ideais para a produção de ácido graxo conjugado foram estudadas e os produtos da reação foram identificados usando a tecnologia GC-MS. Verificou-se que 11 isolados possuem capacidade de produzir CLA em diferentes concentrações. O isolado H1 apresentou a maior produção de ácido graxo conjugado, na concentração de 120,45 g.ml-1, e este isolado foi selecionado como fonte para extração enzimática. A atividade enzimática do extrato bruto e parcialmente purificado com sulfato de amônio foi estimada por métodos de coloração em comprimento de onda de 233 nm. O efeito das condições ótimas (pH, temperatura, concentração de ácido linoleico e concentração de enzima) no produto CLA foi estudado usando a enzima LA Isomerase parcialmente purificada e as condições ótimas para produção foram 6,5, 45 °C, 100 µg.ml-1 e 0,7 mL, respectivamente. A técnica de GC-MS mostrou a presença de uma série de produtos de reação que são isômeros do ácido linoleico conjugado (C9T11, T9T12, T10C12) com diferentes concentrações.


Assuntos
Ácido Linoleico , Leite , Ácidos Graxos , Lactobacillus paracasei
2.
Food Chem ; 400: 134062, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36075165

RESUMO

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are emerging pollutants that threaten food safety. Herein, a rapid, accurate, and selective method for determination of PFOA and PFOS in milk was established by using new molecularly imprinted phenolic resin (MIP-PR) as the adsorbent of dispersive filter extraction (DFE) combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS). MIP-PR was synthesized at room-temperature using m-aminophenol, glutaraldehyde, and perfluorononanoic acid as the monomers, cross-linkers, and virtual templates, respectively, and exhibited rapid mass transfer (30 s), high selectivity (imprinted factors > 3.7), and large adsorption capacity (>54.6 mg/g). Compared with reported methods, the developed MIP-PR-DFE method is fast, selective, inexpensive, and shows good purification and enrichment efficiency. The proposed MIP-PR-DFE-LC-MS/MS exhibited low limits of detection (0.006-0.022 ng/mL), high recoveries (94.7-109 %), and good precision (RSDs ≤ 9.5 %). This study provides a new idea for the development of imprinted resin adsorbents for perfluorinated compound, and a new method for sample pretreatment for monitoring of PFOA and PFOS in food.


Assuntos
Poluentes Ambientais , Impressão Molecular , Ácidos Alcanossulfônicos , Animais , Caprilatos , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida , Poluentes Ambientais/análise , Fluorcarbonetos , Formaldeído , Glutaral , Leite/química , Impressão Molecular/métodos , Fenóis , Polímeros , Extração em Fase Sólida , Espectrometria de Massas em Tandem/métodos
3.
Food Chem ; 400: 134014, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36084587

RESUMO

This study evaluates the use of paper spray ionization mass spectrometry (PSI-MS) for rapid determination of bisphenol A (BPA) and bisphenol S (BPS) in UHT milk and milk packaging. The packages were analyzed by cutting the cartons into triangular shapes and submitting them to PSI-MS analysis. The milk samples were subjected to a simple liquid-liquid extraction and the supernatant was deposited onto a triangular paper that was subsequently used for PSI-MS analysis. In milk, BPS and BPA levels ranged from 60.0 to 150.8 ng mL-1. The LOD and LOQ values were 1.5 and 4.8 ng mL-1 for BPA, and 4.8 and 16.0 ng mL-1 for BPS, respectively. Linearity was R2 > 0.98 for both compounds. Precision values were below 20%, and recoveries close to 100%. The PSI-MS can be used as a simple, rapid, and accurate methodology to determine bisphenols in milk and milk packaging.


Assuntos
Leite , Espectrometria de Massas em Tandem , Animais , Compostos Benzidrílicos/análise , Leite/química , Fenóis/análise , Sulfonas
4.
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
5.
Food Chem ; 400: 134092, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36084600

RESUMO

Chiral analysis of food components can provide important information for food quality, bioactivity and safety. Determination of enantiomeric ratios in food is a tedious task, due to the poor resolution and insufficient sensitivity for simultaneous discrimination and quantification of trace amounts of d-form metabolites. Herein, a high-throughput, high-sensitive and high-resolution method was developed for simultaneously determining enantiomeric ratios of multiple chiral α-hydroxy/amino acids (HA/AAs) from fermented milks in one-run by [d0]/[d5]-estradiol-3-benzoate-17ß-chloroformate labeling-assisted ion mobility - mass spectrometry. Results revealed extensive variation in chiral HA/AA profiles among 15 fermented milks. A total of 14 D-HA/AAs were identified. d-Lactic acid and d-alanine appeared as the most discriminatory in fermented milks with live lactic acid bacteria (LAB). Results suggested that glycolysis, casein hydrolysis and enantioisomerization of HA/AAs were most likely affected by various starter culture LAB. It may contribute to entail a valuable step forward in food quality control and discovering functional-related chiral biomarkers.


Assuntos
Aminoácidos , Caseínas , Alanina/análise , Aminoácidos/análise , Animais , Benzoatos/análise , Caseínas/análise , Estradiol/análise , Hidroxiácidos/análise , Ácido Láctico/análise , Espectrometria de Massas/métodos , Leite/química , Estereoisomerismo
6.
Food Chem ; 400: 133988, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36088888

RESUMO

The present study was designed to study the effect of green solvent processing in two folds, (i) to extract valuable protein from dairy and non-dairy expired milk products and (ii) to compare extraction efficiency and quality of extracted protein using conventional (CS) and green solvents (GS). Ethyl acetate, ethanol, isopropanol, n-heptane and cyclopentyl methyl ether (CPME) were selected as the GS for the possible substitution of hexane and ethyl ether. For each respective solvent, protein recovery, structural and functional modifications were studied. Protein yield was extracted most effectively by GS n-heptane in dairy milk (5.33 ± 0.01%) with a protein purity of 39.73 ± 0.90%. Non-dairy milk and product had similar protein yield when treated with CS and GS. Total mean of extraction efficiency, structural and functional modifications across all samples showed GS solvents were statistically more effective than CS.


Assuntos
Éteres Metílicos , Leite , 2-Propanol , Animais , Etanol , Etil-Éteres , Heptanos , Hexanos/química , Éteres Metílicos/química , Solventes/química
7.
Food Chem ; 398: 133848, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-35964572

RESUMO

Aflatoxin M1 (AFM1) is an important risk factor threatening the safety of milk and dairy products due to its carcinogenic and teratogenic effects on humans. To prevent AFM1 from causing damage to human health, developing reliable methods to monitor its levels in milk and dairy products is of great importance. Biosensors built with recognition and detection systems have attracted extensive attention for their simplicity, portability, sensitivity, and selectivity. The commonly developed biosensors for detecting AFM1 are antibody-based sensors (immunosensors) and aptamer-based sensors (aptasensors). This review focused on the advances of immunosensors, aptasensors, and other emerging receptors-based sensors for the detection of AFM1 in milk and dairy products in the past five years. These biosensors were reviewed with representative examples according to their signal transduction systems, mainly including colorimetry, fluorescence, electrochemistry, and others. The unique advantages and drawbacks of immunosensor and aptasensor, and the future opportunities and challenges were also discussed.


Assuntos
Aflatoxina M1 , Técnicas Biossensoriais , Aflatoxina M1/análise , Animais , Técnicas Biossensoriais/métodos , Laticínios/análise , Eletroquímica , Contaminação de Alimentos/análise , Humanos , Imunoensaio , Leite/química
8.
Food Chem ; 399: 133877, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36037682

RESUMO

The comparison between the crystallization and phase behavior of binary blends of anhydrous milk fat (AMF)/palm stearin (POs) and POs/palm oil (PO) was investigated. POs/POs blends showed good compatibility, while the compatibility of AMF/POs blends showed no ideal and was dominated by eutectic behavior. And the eutectic growth of blends was found to be a phenomenon that the triacylglycerol (TAG) of AMF grew on the peripheral of POs seed crystals. In binary blends, the addition of POs not only increased the liquid phase transition temperature but also induced the formation of ß crystal forms in more than 70% POs. The addition of soybean oil to binary blends could improve the compatibility of the ternary system. It eventually provided potential formulations for the production of non-hydrogenated puff pastry margarine.


Assuntos
Leite , Óleos Vegetais , Animais , Cristalização , Óleo de Palmeira/química , Óleos Vegetais/química , Triglicerídeos/química
9.
Food Chem ; 399: 133987, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36037686

RESUMO

αs1-Casein (αs1-CN) is a major cow milk allergen, while the tertiary structure of αs1-CN and conformational epitopes of αs1-CN have not been clarified. Here, a reasonable three-dimensional structure of αs1-CN was established using ab initio methods, and hot-spot residues and epitopes were investigated by combining molecular dynamics simulation, peptides synthesis, and ELISA. Obtained results demonstrated that the binding mechanism between αs1-CN and IgG was located on three main regions: a helical structure zone (E77-Q97), the flexible loop zone (Y154-T174), and a flexible C-terminal (N190-L198), mainly connecting via hydrogen bond and ionic bonds. The hydrolysates produced by papain with lowest antigenicity (12.43%), which could considerably destroy the essential epitopes of αs1-CN confirmed by epitope synthesis, and LC-MS/MS. The results reported herein would provide novel insights into the interface interactions between αs1-CN and IgG, and prove valuable for developing hypoallergenic infant-formula and peptide vaccines for allergen-specific immunotherapy.


Assuntos
Caseínas , Espectrometria de Massas em Tandem , Alérgenos , Animais , Caseínas/química , Bovinos , Cromatografia Líquida , Epitopos , Feminino , Humanos , Imunoglobulina G/análise , Leite/química
10.
Food Microbiol ; 109: 104145, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36309427

RESUMO

A cross-sectional study was conducted to investigate the prevalence and risk factors for contamination of Ethiopian dairy products with Campylobacter. A total of 912 dairy food samples were collected from establishments of 682 study participants that were interviewed. Samples were tested for Campylobacter by following the ISO 10272-1:2017 standard and PCR confirmation. Campylobacter was detected in 11% of tested food samples and all detected Campylobacter were C. jejuni. The highest prevalence of C. jejuni was found in raw milk (16%), followed by pasteurized milk (9%) and cottage cheese (2%) (P < 0.001). Using warm water and soap for cleaning cow udders and teats on farms reduced the likelihood of detecting Campylobacter in milk (AOR = 0.3, P = 0.023). Filtering milk with a cloth, using a plastic filter (AOR = 0.065, P = 0.005), and storing milk in an aluminum container (AOR = 0.23, P = 0.027) reduced the likelihood of detecting Campylobacter in milk at the collection facilities. In contrast, Campylobacter detection was significantly more likely in milk collected at collection centers with concrete floors (AOR = 5.2, P = 0.004). The odds of detecting Campylobacter in milk were 17 times greater (AOR = 17, P = 0.007) in milk processing facilities that did not calibrate a pasteurizer on an annual basis. Finally, having a separate refrigerator for milk storage reduced the odds of detecting Campylobacter in retail (AOR = 0.29, P = 0.021).


Assuntos
Campylobacter jejuni , Campylobacter , Bovinos , Animais , Feminino , Leite , Campylobacter/genética , Etiópia/epidemiologia , Prevalência , Estações do Ano , Estudos Transversais , Fatores de Risco , Microbiologia de Alimentos
11.
Food Microbiol ; 109: 104143, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36309444

RESUMO

The objective of the present study was to compare the growth of food-pathogens Listeria monocytogenes, Salmonella enterica, food spoilage Bacillus subtilis, an industrial milk product isolate, and spore-forming Paenibacillus in commercially available ultrahigh temperature processed (UHT) bovine milk and non-dairy, plant-based beverages (coconut, almond, cashew) stored at chilled and ambient temperatures (4 °C, 8 °C or 20 °C). Beverage samples were inoculated with a strain cocktail or individual strains of either Listeria or Salmonella, or Paenibacillus or Bacillus, respectively (approximately 1 × 103 CFU/mL). The findings indicate that the bacterial strains used in the study were capable of proliferating in plant-based beverages at higher rates than in bovine milk at 8 °C and 20 °C for Listeria and 20 °C for Salmonella and Paenibacillus, respectively. Bacillus subtilis grew equally fast in bovine milk and plant-based almond drink at 20 °C. No statistically significant difference (p > 0.05) in growth rates between different types of tested beverages was observed at 4 °C and at 8 °C for Listeria and Salmonella cocktails, respectively. These data suggest that plant-based beverages may present a significant risk for listeriosis and salmonellosis and post-opening recommendations should be carefully considered.


Assuntos
Bacillus , Listeria monocytogenes , Listeria , Paenibacillus , Animais , Leite/microbiologia , Microbiologia de Alimentos , Contagem de Colônia Microbiana , Esporos Bacterianos , Salmonella
12.
Food Microbiol ; 109: 104154, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36309450

RESUMO

Wooden vats are used in the production of some traditional cheeses as the biofilms on wooden vat surfaces are known to transfer large quantities of microbes to cheese. However, very few studies have investigated the microbial composition of biofilms on newly developed wooden vats and how communities assemble and evolve. In the present study, the microbial communities of biofilms were characterized over the activation process on new wooden vats using amplicon sequencing of bacterial 16s rRNA and fungal internal transcribed spacer genes. Results showed that microbes from the whey effectively developed on wooden vats. Lactococcus was highly dominant throughout the vat activation process with substantial increases in the relative abundance of Acetobacter and Lactobacillus at the end of the vat activation (day 7). This was in contrast with fungal communities that stabilized early (day 1) and were dominated by Kluyveromyces. Predicted functions corresponded with the different stages of biofilm formation whereby functions associated with biofilm initiation were enriched on day 1 and those associated with growth and maturation were enriched on days 4 and 7. Microbial succession on wooden vat surfaces is expected to be reproducible based on the early onset and dominance of the deterministic process.


Assuntos
Queijo , Microbiota , Animais , Queijo/microbiologia , RNA Ribossômico 16S/genética , Leite/microbiologia , Microbiota/genética , Biofilmes
13.
Food Microbiol ; 109: 104150, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36309452

RESUMO

Routine monitoring of foodborne pathogens such as Listeria monocytogenes in food processing environments are time-consuming necessities to ensure food safety. Alternative rapid diagnostic methods for pathogen detection are increasingly used, but often demand specialized equipment, making them unsuitable for on-site testing. This short communication describes the successful demonstration of combining the sample preparation method Matrix-Lysis with a chemiluminescent based detection platform (AquaSpark™) for detection of L. monocytogenes in milk and yogurt. The proposed method was evaluated against qPCR resulting in 100% relative specificity for both foodstuffs and a relative sensitivity of 100% for milk as well as 96% for yogurt for bacterial levels >1 CFU/ml. Only at very low initial bacterial concentrations (<1 CFU/ml) diverging results were found highlighting the advantages and limitations of both methods. While being less susceptible to contamination and false positive results from non-growing or dead cells, qPCR had a slightly lower overall detection limit. However, it has to be pointed out that qPCR has an increased analytical cost and also requires an additional 24 h analysis time. This study demonstrates the first successful application of a chemilumonogenic detection approach for L. monocytogenes in food that has a high potential for on-site testing.


Assuntos
Listeria monocytogenes , Animais , Listeria monocytogenes/genética , Microbiologia de Alimentos , Laticínios/microbiologia , Leite/microbiologia , Reação em Cadeia da Polimerase em Tempo Real , Iogurte
14.
Food Chem ; 402: 134433, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36303364

RESUMO

An innovative bimetallic gold-silver core-shell nanoflowers (Au@Ag-CSNFs) SERS substrate has been synthesized by a facile electrochemical reduction process on an indium tin oxide (ITO) glass with a total fabrication time of 3 min. The proposed Au@Ag-CSNFs SERS substrate has been distributed evenly with numerous interstices and cavities between each branch, suggesting potential target trap sites and "hot spots". The Au@Ag-CSNFs administered good reproducibility of SERS signals collected from 140 random spots with a relative standard deviation and an enhancement factor of 13.62 % and 0.9 × 107, respectively. The substrate was further extended for the label-free SERS sensing of thiram residues with an ultra-low detection limit of 7.088 × 10-8 mol/L. The designed probe was further subjected to thiram determination in real milk and juice samples with satisfactory recoveries (91.76-109.40 %). The rapidly synthesized Au@Ag-CSNFs substrate can be extended for SERS sensing in a variety of hazards in food settings.


Assuntos
Nanopartículas Metálicas , Tiram , Animais , Tiram/análise , Nanopartículas Metálicas/química , Análise Espectral Raman , Leite/química , Reprodutibilidade dos Testes , Ouro/química
15.
Food Chem ; 402: 134150, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36303374

RESUMO

In this work, a novel electrochemical aptasensor was designed for the sensitive and specific detection of STR in milk samples. First, a gold nanoparticle@poly(diallyldimethylammonium chloride) nitrogen-doped carbon nanotube/polyethyleneimine-functionalized metal-organic framework (MOF) (Au@P-N-CNT/PEI-MIL-101(Cr)) composite was synthesized and characterized by various technique. The Au@P-N-CNT/PEI-MIL-101(Cr) composite was then modified on a bare glassy carbon electrode (GCE) surface, providing a favorable platform (Au@P-N-CNT/PEI-MIL-101(Cr)/GCE) for aptamer immobilization and current signal amplification. The STR aptamer was grafted to the Au@P-N-CNT/PEI-MIL-101(Cr)/GCE through the formation of Au-S bonds and π-π stacking interactions. The immobilized STR aptamer binds specifically STR, resulting in an obvious decrease in the current signal. Under the optimal experimental conditions, the linear range of the electrochemical aptasensor for STR detection was 0.01-250 nM which the detection limit (LOD) was calculate as 2.31 nM. This strategy is expected to be a novel platform for the rapid and sensitive detection of STR.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Grafite , Nanopartículas Metálicas , Estruturas Metalorgânicas , Nanotubos de Carbono , Animais , Ouro/química , Nanotubos de Carbono/química , Estruturas Metalorgânicas/química , Aptâmeros de Nucleotídeos/química , Estreptomicina , Técnicas Eletroquímicas/métodos , Técnicas Biossensoriais/métodos , Leite , Grafite/química , Limite de Detecção , Nanopartículas Metálicas/química , Polietilenoimina/química
16.
Food Chem ; 403: 134399, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36182859

RESUMO

Exploiting a simple and sensitive sensor to efficiently detect streptomycin (STR) in milk is critical for resolving the harm caused to humans by STR residues. This study reports an electrochemical sensor using magnetic mesoporous carbon materials (MMCM) as a loaded material through magnetic adsorption immobilized on magnetic glassy carbon electrode (MGCE) and adsorbing unlabeled streptomycin aptamer (STP) as the identification element. The sensor can detect STR sensitively with a wide detection range (0.172-17.2 × 103 and 17.2 × 103 -17.2 × 105 nM) and a low detection limit of 0.015 nM. Experimental results revealed that the specific binding of STP with STR on the electrode changed the configuration of STP, thereby causing current change of differential pulse voltammetry curve. Compared with HPLC, this study provides a new method for rapid and sensitive detection of STR in milk (n = 5, 95 % confidence level, RSD<5%).


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Humanos , Animais , Estreptomicina , Leite/química , Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/métodos , Adsorção , Eletrodos , Carbono/análise , Fenômenos Magnéticos , Técnicas Eletroquímicas/métodos , Limite de Detecção
17.
Food Chem ; 403: 134315, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36183466

RESUMO

Sixteen multiparous Holstein cows in four blocks of 4 × 4 Latin square over 4-week experimental periods were used to study the effects of seaweed (Saccharina latissima) supplement (with/without) and protein source (rapeseed meal (RSM)/wheat distiller's grain (WDG)) on milk mineral concentrations. Dietary treatments did not affect milk production and basic composition. Feeding seaweed slightly decreased milk Ca and Cu concentrations; whilst increased (by 3.3-fold) milk iodine (I) concentration, due to a higher dietary I supply. Substitution of WDG with RSM increased feed-to-milk transfer of Ca, Na, and Se and decreased that of Mg, P, Fe, and Mn; but only reduced milk Mn and I concentrations (the latter by 27 % as a potential result of increased glucosinolate intake). Seaweed supplement can improve milk I content when cows' I supply/availability is limited, but care should be taken to avoid excess milk I contents that may pose nutritional risks for young children.


Assuntos
Brassica napus , Brassica rapa , Feófitas , Alga Marinha , Feminino , Bovinos , Animais , Leite/metabolismo , Lactação , Ração Animal/análise , Dieta/veterinária , Suplementos Nutricionais , Grão Comestível , Verduras , Minerais/metabolismo
18.
Food Chem ; 403: 134403, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36191419

RESUMO

The objectives of this study were to explore the use of Fourier-transform infrared (FITR) spectroscopy on 458 goat milk samples for predicting cheese-making traits, and to test the effect of the farm variability on their prediction accuracy. Calibration equations were developed using a Bayesian approach with three different scenarios: i) a random cross-validation (CV) [80% calibration (CAL); 20% validation (VAL) set], ii) a stratified CV [(SCV), 13 farms used as CAL, and the remaining one as VAL set], and iii) a SCV where 20% of the goats randomly selected from the VAL farm were included in the CAL set (SCV80). The best prediction performance was obtained for cheese yield solids, justifying for its practical application at population level. Overall results were similar to or outperformed those reported for bovine milk. Our results suggest considering specific procedures for calibration development to propose reliable tools applicable along the dairy goat chain.


Assuntos
Queijo , Humanos , Animais , Queijo/análise , Leite/química , Teorema de Bayes , Cabras , Espectroscopia de Infravermelho com Transformada de Fourier
19.
Food Chem ; 403: 134408, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36194930

RESUMO

In this paper, a stir membrane liquid-phase microextraction approach based on milk fats hydrolysis and in situ deep eutectic solvent formation was developed for the first time. The approach was applied to clean-up and preconcentrate bisphenols from milk samples. The procedure assumed alkaline hydrolysis of samples fats to obtain water-soluble salts of fatty acids that acted as precursors for the deep eutectic solvent formation. A stir membrane disk impregnated with menthol was placed into the sample solution. The formation of microdroplets of the hydrophobic fatty acids was observed under sample acidification. Collection of the extract phase on the disk was based on deep eutectic solvent formation. Under optimal conditions, the RSD was < 6 %, limits of detection for bisphenols were 0.3-0.5 µg kg-1. The extraction recoveries were in the range of 95-97 %, which indicated the excellent capability of the developed approach to extract hydrophobic analytes from complex matrices.


Assuntos
Microextração em Fase Líquida , Leite , Animais , Solventes/química , Leite/química , Solventes Eutéticos Profundos , Hidrólise , Microextração em Fase Líquida/métodos , Ácidos Graxos/análise , Limite de Detecção
20.
J Environ Manage ; 325(Pt A): 116400, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36270127

RESUMO

Domesticated ruminants supply nutrient-dense foods but at a large environmental cost. However, many ruminant production systems are multi-functional, providing ecosystem services (ES) other than direct provision of food. When quantifying the climate impact of ruminant products using life cycle assessment (LCA), provisioning ES (i.e. beef and milk) are generally considered the only valuable outputs and other ES provided are ignored, which risks overlooking positive contributions associated with ruminant production. Non-provisioning ES can be included in LCA by economic allocation, using compensatory payments (through agri-environmental schemes) as a proxy for the economic value of ES. For example, farmers can receive payments for maintenance of pastures, which supports e.g. pollination. However, the association between different payment schemes, the ES provided, and livestock production is not always straightforward and it can be difficult to determine which payment schemes to include in the allocation. This study examined how accounting for ES in quantification of climate impact for beef and milk production on Swedish farms was affected by different ways of coupling ES to livestock production through payment schemes. Quantification was done using LCA, attributing the climate impact to beef, milk, and other ES by economic allocation. This resulted in <1-48% and 11-31% of climate impacts being allocated to other ES, instead of beef and milk, respectively, affecting suckler farms most. The results were influenced by which payment schemes, representing different ES, that were included; when only payments directly related to livestock rearing were included, the difference in the climate impact was still large between farm types, while the difference decreased considerably when all environmental schemes were included. While emissions do not disappear, ES-corrected climate impact can potentially be useful as part of consumer communication or in decision-making, reducing the risk of overlooking ES provided by ruminant production in a simpler way than using separate indicators.


Assuntos
Ecossistema , Leite , Animais , Bovinos , Ruminantes , Gado , Fazendas
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