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1.
Food Chem ; 304: 125428, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31476548

RESUMO

To protect allergic patients and guarantee correct food labeling, robust, specific and sensitive detection methods are urgently needed. Mass spectrometry (MS)-based methods could overcome the limitations of current detection techniques. The first step in the development of an MS-based method is the identification of biomarkers, which are, in the case of food allergens, peptides. Here, we implemented a strategy to identify the most salient peptide biomarkers in peanuts. Processed peanut matrices were prepared and analyzed using an untargeted approach via high-resolution MS. More than 300 identified peptides were further filtered using selection criteria to strengthen the analytical performance of a future, routine quantitative method. The resulting 16 peptides are robust to food processing, specific to peanuts, and satisfy sequence-based criteria. The aspect of multiple protein isoforms is also considered in the selection tree, an aspect that is essential for a quantitative method's robustness but seldom, if ever, considered.

2.
Food Chem ; : 125679, 2019 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-31718834

RESUMO

The interest of using LC-MS/MS as a method for detection of allergens in food is growing. In such methods, peptides are used as biomarkers for the detection and quantification of the allergens. The selection of good biomarker peptides is of high importance to develop a specific, universal and sensitive method. Biomarkers should, for example, be robust to food processing. To evaluate robustness, test material incurred with hazelnut having undergone different food processing techniques was produced. Proteins of these materials were extracted, digested and further analyzed using HRMS. After peptide identification, selection was carried out using several criteria such as hazelnut specificity and amino acid composition. Further selection was done by comparing peptide MS intensities in the different food matrices. Only peptides showing processing robustness were retained. Eventually, eight peptides coming from three major hazelnut proteins were selected as the best biomarkers for hazelnut detection in processed foods.

3.
J AOAC Int ; 102(5): 1346-1353, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-30940282

RESUMO

Risk-based approaches to managing allergens in foods are being developed by the food industry and regulatory authorities to support food-allergic consumers to avoid ingestion of their problem food, especially in relation to the traces of unintended allergens. The application of such approaches requires access to good quality data from clinical studies to support identification of levels of allergens in foods that are generally safe for most food-allergic consumers as well as analytical tools that are able to quantify allergenic food protein. The ThRAll project aims to support the application of risk-based approaches to food-allergen management in two ways. First, a harmonized quantitative MS-based prototype reference method will be developed for the detection of multiple food allergens in standardized incurred food matrices. This will be undertaken for cow's milk, hen's egg, peanut, soybean, hazelnut, and almond incurred into two highly processed food matrices, chocolate and broth powder. This activity is complemented by a second objective to support the development and curation of data on oral food challenges, which are used to define thresholds and minimum eliciting doses. This will be achieved through the development of common protocols for collection and curation of data that will be applied to allergenic foods for which there are currently data gaps.

4.
Int J Mol Sci ; 20(6)2019 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-30909578

RESUMO

In Europe, the toxicological safety of genetically modified (GM) crops is routinely evaluated using rodent feeding trials, originally designed for testing oral toxicity of chemical compounds. We aimed to develop and optimize methods for advancing the use of zebrafish feeding trials for the safety evaluation of GM crops, using maize as a case study. In a first step, we evaluated the effect of different maize substitution levels. Our results demonstrate the need for preliminary testing to assess potential feed component-related effects on the overall nutritional balance. Next, since a potential effect of a GM crop should ideally be interpreted relative to the natural response variation (i.e., the range of biological values that is considered normal for a particular endpoint) in order to assess the toxicological relevance, we established natural response variation datasets for various zebrafish endpoints. We applied equivalence testing to calculate threshold equivalence limits (ELs) based on the natural response variation as a method for quantifying the range within which a GM crop and its control are considered equivalent. Finally, our results illustrate that the use of commercial control diets (CCDs) and null segregant (NS) controls (helpful for assessing potential effects of the transformation process) would be valuable additions to GM safety assessment strategies.


Assuntos
Ração Animal , Alimentos Geneticamente Modificados , Análise de Perigos e Pontos Críticos de Controle , Plantas Geneticamente Modificadas , Peixe-Zebra , Ração Animal/efeitos adversos , Ração Animal/análise , Animais , Suplementos Nutricionais , Análise de Alimentos , Inocuidade dos Alimentos , Perfilação da Expressão Gênica , Análise de Perigos e Pontos Críticos de Controle/métodos , Fígado/metabolismo , Masculino , Testes de Toxicidade , Zea mays , Peixe-Zebra/genética
5.
Int Arch Allergy Immunol ; 179(1): 1-9, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30893694

RESUMO

BACKGROUND: The double-blind, placebo-controlled food challenge (DBPCFC) is still considered to be the gold standard in food allergy diagnosis. This test is however not common practice in routine due to several practical limitations, especially for non-IgE-mediated food allergy with its typical delayed food allergic reactions. OBJECTIVE: The aim of this study was to develop and evaluate DBPCFC matrices for the diagnosis of milk and egg allergies which can be applied at home for the diagnosis of delayed food allergic reactions. The main focus was the blinding of milk and raw egg and the development of matrices which can be prepared and consumed conveniently at home with a sufficiently long shelf life (+/- 6 months or longer). METHODS: A sensory test evaluated the blinding of the egg and milk in the matrices. The microbiological analysis confirmed the safety and stability of the developed matrices. To assess the applicability of the matrices, a pilot DBPCFC study for milk including 7 patients was conducted. RESULTS: Sensory tests confirmed that the masking of the allergenic ingredients was sufficient. Microbial safety and stability of the matrices were confirmed up to 6 months of storage at ambient temperatures in the dark. The DBPCFC for milk showed different outcomes and proved its applicability for use at home. CONCLUSION: A novel stable DBPCFC matrix for milk and raw egg has been developed that allows convenient use at the patients' home.


Assuntos
Hipersensibilidade a Ovo/diagnóstico , Hipersensibilidade a Leite/diagnóstico , Adulto , Criança , Pré-Escolar , Método Duplo-Cego , Feminino , Humanos , Masculino , Placebos , Sensação , Testes Cutâneos
6.
3 Biotech ; 8(8): 349, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30073134

RESUMO

Chicory capable of synthesizing long-chain inulin is of great interest. During the growing season, the sucrose-sucrose 1-fructosyltransferase (1-SST) activity is vital for production of long-chain inulin in chicory. With the purpose to increase inulin chain length, we employed Agrobacterium-mediated transformation method. Transgenic chicory plants (Cichorium intybus L. var. sativum) cv. 'Melci' has been developed to overexpress sucrose-sucrose 1-fructosyltransferase (1-SST) under the control of the CaMV 35S promoter. The integration of the T-DNA into the plant genome was confirmed by PCR on genomic DNA using gene-specific primers. Quantification of the 1-SST transcript expression level revealed that transgenic plants showed higher 1-SST expression than those in non-transgenic plants. Further analyses proved that the fructan content of the roots significantly increased in the transgenic plants. These results revealed that overexpression of the 1-SST, the key gene in inulin biosynthesis in chicory, might serve as a novel approach to develop plants with the long-chain inulin content.

7.
Clin Transl Allergy ; 8: 3, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29416847

RESUMO

Background: Double-blind, placebo-controlled food challenge (DBPCFC) is considered the gold standard for food allergy diagnosis. However, this test is rarely performed routinely in clinical practice because of various practical issues, e.g. the lack of a standardized matrix preparation. The aim of this study was to develop and validate a convenient DBPCFC matrix, that can easily be implemented in daily clinical practice. The focus of this study was the blinding of hazelnuts, whereby the hazelnuts retained as much as possible their allergenicity and could be mixed homogenously in low-doses to the matrices. Methods: A basophil-activation test (BAT), microbial tests and an LC-MS/MS test were performed to assess respectively the allergenicity of the used hazelnuts, the microbial stability of the novel developed matrices and the homogeneity of the hazelnuts in the matrices. A sensory test was conducted to validate the blinding of the hazelnuts in the matrices. A pilot DBPCFC study included eight patients as proof of concept. Results: The BAT-test gave the first insights concerning the retained allergenicity of the hazelnuts. The microbial safety could be assured after 12 months of storage. Sufficient masking was assessed by several sensory tests. Homogeneous hazelnut distribution could be achieved for the different hazelnut concentrations. The DBPCFC's results showed diverse allergic responders (from no reactions to distinct objective symptoms). Conclusion: A novel stable and validated DBPCFC matrix using raw hazelnuts has been developed that allows easy preparation in a standardized way for convenient use in daily clinical practice.Trial registration EC Project number: EC/2015/0852; Date of registration: 13 Oct 2015; End date: 01 Feb 2017.

8.
Anal Bioanal Chem ; 409(22): 5201-5207, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28744561

RESUMO

The recent detection of nuts (including peanut) in spices across the globe has led to enormous recalls of several spices and food products in the last two years. The lack of validated detection methods specific for spices makes it difficult to assess allergen presence at trace levels. Because of the urgent need for confirmation of possible peanut presence in chili peppers, an LC-MS/MS method was optimized and developed for this particular food matrix. Although several studies optimized LC-MS detection strategies specific for peanuts, the presence of complex components in the spices (e.g., phenolic components) makes method optimization and validation necessarily. Focus was laid on validation of the method with real incurred chili peppers (whereby a known amount of peanut is added) at low concentrations, to deal with possible matrix interferences. LC-MS/MS proves to be a good alternative to the currently most applied methods (ELISA and RT-PCR) and can be used as a complementary method of analysis when results are unclear. Peanut marker peptides were selected based on their abundancy in digested incurred chili peppers. The limit of detection was determined to be 24 ppm (mg peanut/kg), a level whereby the risk for potential allergic reactions is zero, considering the typical portion size of spices. The chili pepper powder under investigation proved to contain low levels of peanuts after LC-MS/MS, ELISA, and RT-PCR testing. Graphical abstract Standard curve of the detected peanuts in chili pepper samples using the novel LC-MS/MS method.


Assuntos
Alérgenos/análise , Arachis/química , Capsicum/química , Análise de Alimentos/métodos , Alérgenos/química , Cromatografia Líquida , Ensaio de Imunoadsorção Enzimática , Contaminação de Alimentos/análise , Limite de Detecção , Peptídeos/análise , Peptídeos/química , Reação em Cadeia da Polimerase , Espectrometria de Massas em Tandem
9.
Food Chem ; 232: 351-358, 2017 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-28490084

RESUMO

Recently, we developed a DNA walking system for the detection and characterization of a broad spectrum of GMOs in routine analysis of food/feed matrices. Here, we present a new version with improved throughput and sensitivity by coupling the DNA walking system to Pacific Bioscience® Next-generation sequencing technology. The performance of the new strategy was thoroughly assessed through several assays. First, we tested its detection and identification capability on grains with high or low GMO content. Second, the potential impacts of food processing were investigated using rice noodle samples. Finally, GMO mixtures and a real-life sample were analyzed to illustrate the applicability of the proposed strategy in routine GMO analysis. In all tested samples, the presence of multiple GMOs was unambiguously proven by the characterization of transgene flanking regions and the combinations of elements that are typical for transgene constructs.


Assuntos
Alimentos Geneticamente Modificados , DNA de Plantas , Sequenciamento de Nucleotídeos em Larga Escala , Oryza , Plantas Geneticamente Modificadas , Análise de Sequência de DNA
10.
Trends Biotechnol ; 35(6): 508-517, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28347568

RESUMO

Current GMO detection systems have limited abilities to detect unauthorized genetically modified organisms (GMOs). Here, we propose a new workflow, based on next-generation sequencing (NGS) technology, to overcome this problem. In providing information about DNA sequences, this high-throughput workflow can distinguish authorized and unauthorized GMOs by strengthening the tools commonly used by enforcement laboratories with the help of NGS technology. In addition, thanks to its massive sequencing capacity, this workflow could be used to monitor GMOs present in the food and feed chain. In view of its potential implementation by enforcement laboratories, we discuss this innovative approach, its current limitations, and its sustainability of use over time.


Assuntos
Análise de Alimentos/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Organismos Geneticamente Modificados/genética , Animais , Humanos
11.
Food Chem ; 192: 788-98, 2016 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-26304412

RESUMO

Because the number and diversity of genetically modified (GM) crops has significantly increased, their analysis based on real-time PCR (qPCR) methods is becoming increasingly complex and laborious. While several pioneers already investigated Next Generation Sequencing (NGS) as an alternative to qPCR, its practical use has not been assessed for routine analysis. In this study a statistical framework was developed to predict the number of NGS reads needed to detect transgene sequences, to prove their integration into the host genome and to identify the specific transgene event in a sample with known composition. This framework was validated by applying it to experimental data from food matrices composed of pure GM rice, processed GM rice (noodles) or a 10% GM/non-GM rice mixture, revealing some influential factors. Finally, feasibility of NGS for routine analysis of GM crops was investigated by applying the framework to samples commonly encountered in routine analysis of GM crops.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala/métodos , Plantas Geneticamente Modificadas/genética , Sequência de Bases , Produtos Agrícolas/genética , DNA de Plantas/genética , Estudos de Viabilidade , Biblioteca Gênica , Genes de Plantas , Dados de Sequência Molecular , Oryza/genética , Reação em Cadeia da Polimerase em Tempo Real , Reprodutibilidade dos Testes , Alinhamento de Sequência , Análise de Sequência de DNA , Transgenes
12.
Biomed Res Int ; 2015: 392872, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26550567

RESUMO

In many countries, genetically modified organisms (GMO) legislations have been established in order to guarantee the traceability of food/feed products on the market and to protect the consumer freedom of choice. Therefore, several GMO detection strategies, mainly based on DNA, have been developed to implement these legislations. Due to its numerous advantages, the quantitative PCR (qPCR) is the method of choice for the enforcement laboratories in GMO routine analysis. However, given the increasing number and diversity of GMO developed and put on the market around the world, some technical hurdles could be encountered with the qPCR technology, mainly owing to its inherent properties. To address these challenges, alternative GMO detection methods have been developed, allowing faster detections of single GM target (e.g., loop-mediated isothermal amplification), simultaneous detections of multiple GM targets (e.g., PCR capillary gel electrophoresis, microarray, and Luminex), more accurate quantification of GM targets (e.g., digital PCR), or characterization of partially known (e.g., DNA walking and Next Generation Sequencing (NGS)) or unknown (e.g., NGS) GMO. The benefits and drawbacks of these methods are discussed in this review.


Assuntos
Análise de Alimentos/métodos , Alimentos Geneticamente Modificados/classificação , Organismos Geneticamente Modificados/genética , Reação em Cadeia da Polimerase/métodos , Análise de Sequência de DNA/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
13.
BMC Biotechnol ; 15: 76, 2015 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-26272331

RESUMO

BACKGROUND: In order to provide a system fully integrated with qPCR screening, usually used in GMO routine analysis, as well as being able to detect, characterize and identify a broad spectrum of GMOs in food/feed matrices, two bidirectional DNA walking methods targeting p35S or tNOS, the most common transgenic elements found in GM crops, were developed. These newly developed DNA walking methods are completing the previously implemented DNA walking method targeting the t35S pCAMBIA element. METHODS: Food/feed matrices containing transgenic crops (Bt rice or MON863 maize) were analysed using the integrated DNA walking system. RESULTS: First, the newly developed DNA walking methods, anchored on the sequences used for the p35S or tNOS qPCR screening, were tested on Bt rice that contains these two transgenic elements. Second, the methods were assessed on a maize sample containing a low amount of the GM MON863 event, representing a more complex matrix in terms of genome size and sensitivity. Finally, to illustrate its applicability in GMO routine analysis by enforcement laboratories, the entire workflow of the integrated strategy, including qPCR screening to detect the potential presence of GMOs and the subsequent DNA walking methods to characterize and identify the detected GMOs, was applied on a GeMMA Scheme Proficiency Test matrix. Via the characterization of the transgene flanking region between the transgenic cassette and the plant genome as well as of a part of the transgenic cassette, the presence of GMOs was properly confirmed or infirmed in all tested samples. CONCLUSION: Due to their simple procedure and their short time-frame to get results, the developed DNA walking methods proposed here can be easily implemented in GMO routine analysis by the enforcement laboratories. In providing crucial information about the transgene flanking regions and/or the transgenic cassettes, this DNA walking strategy is a key molecular tool to prove the presence of GMOs in any given food/feed matrix.


Assuntos
Passeio de Cromossomo/métodos , DNA de Plantas/genética , Alimentos Geneticamente Modificados , Plantas Geneticamente Modificadas , Humanos , Reação em Cadeia da Polimerase em Tempo Real
14.
Food Chem ; 173: 827-37, 2015 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-25466096

RESUMO

In this study, a process for the production of premium quality yellowish, cloudy pear juice from low-quality fruit under low-oxygen conditions was developed. The production process consisted of (1) shredding, (2) pressing with spiral-filter technology including a vacuumised extraction cell, (3) holding in an inert gas buffer tank, (4) pasteurisation, (5) and refrigerated storage. First, the system parameters of a spiral-filter press were optimised with the aim of producing a yellowish, cloudy pear juice with the highest possible juice yield. A maximum juice yield of 78% could be obtained. Enzymatic browning during juice extraction could be suppressed as a result of the fast processing and the low air (oxygen) levels in the extraction chamber of the spiral-filter press. Furthermore, we observed that instantaneous pasteurisation at 107 °C for 6s, subsequent aluminium laminate packaging and cold storage had only a minimum effect on the phenolic composition.


Assuntos
Bebidas , Indústria Alimentícia/métodos , Frutas/química , Pyrus/química , Oxigênio , Fenóis/análise
15.
Food Chem ; 173: 986-96, 2015 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-25466116

RESUMO

In this study, advantages and disadvantages of the innovative, low-oxygen spiral-filter press system were studied in comparison with the belt press, commonly applied in small and medium size enterprises for the production of cloudy apple juice. On the basis of equivalent throughput, a higher juice yield could be achieved with spiral-filter press. Also a more turbid juice with a higher content of suspended solids could be produced. The avoidance of enzymatic browning during juice extraction led to an attractive yellowish juice with an elevated phenolic content. Moreover, it was found that juice produced with spiral-filter press demonstrates a higher retention of phenolic compounds during the downstream processing steps and storage. The results demonstrates the advantage of the use of a spiral-filter press in comparison with belt press in the production of a high quality cloudy apple juice rich in phenolic compounds, without the use of oxidation inhibiting additives.


Assuntos
Bebidas/análise , Filtração/métodos , Indústria Alimentícia/instrumentação , Frutas/química , Malus/química , Indústria Alimentícia/métodos , Fenóis/análise
16.
Food Chem ; 173: 1259-65, 2015 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-25466152

RESUMO

To identify unauthorised GMOs in food and feed matrices, an integrated approach has recently been developed targeting pCAMBIA family vectors, highly present in transgenic plants. Their presence is first assessed by qPCR screening and is subsequently confirmed by characterising the transgene flanking regions, using DNA walking. Here, the DNA walking performance has been thoroughly tested for the first time, regarding the targeted DNA quality and quantity. Several assays, on model food matrices mimicking common rice products, have allowed to determine the limit of detection as well as the potential effects of food mixture and processing. This detection system allows the identification of transgenic insertions as low as 10 HGEs and was not affected by the presence of untargeted DNA. Moreover, despite the clear impact of food processing on DNA quality, this method was able to cope with degraded DNA. Given its specificity, sensitivity, reliability, applicability and practicability, the proposed approach is a key detection tool, easily implementable in enforcement laboratories.


Assuntos
DNA de Plantas/isolamento & purificação , Alimentos Geneticamente Modificados , Oryza/genética , Plantas Geneticamente Modificadas/genética , Clonagem Molecular , DNA de Plantas/genética , Manipulação de Alimentos/métodos , Reação em Cadeia da Polimerase em Tempo Real , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Análise de Sequência de DNA
17.
J Sci Food Agric ; 94(6): 1168-74, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24105673

RESUMO

BACKGROUND: Evaluating the effect of domestic cooking on the health benefits of vegetables has great practical importance. However, only a limited number of reports provide information on the effect of these treatments on the antioxidant capacity, polyphenol and S-alk(en)yl-L-cysteine sulfoxide (ACSO, e.g. isoalliin and methiin) content of the white shaft and green leaves of leek (Allium ampeloprasum var. porrum). RESULTS: In the present study, the antioxidant capacity of leek was highly influenced by cooking (blanching, boiling and steaming). Boiling had a negative effect on total phenolic content in the white shaft and green leaves. An obvious increase could be observed in the antioxidant capacity of the steamed green leaves, while steaming did not influence the polyphenolic content. Remarkably, blanching resulted in a slight increase in the ACSO content. Subjecting leek samples to a longer thermal treatment appeared to have a negative influence on the ACSO content in leek. Steaming was also responsible for a decrease in ACSOs. Methiin was less susceptible to heat treatment than isoalliin. CONCLUSION: In general, steaming appeared to be responsible for better retention of the bioactive compounds present in leek compared with boiling.


Assuntos
Antioxidantes/análise , Culinária/métodos , Cisteína/análise , Manipulação de Alimentos/métodos , Temperatura Alta , Cebolas/química , Fenóis/análise , Cisteína/análogos & derivados , Dieta , Humanos , Folhas de Planta/química , Caules de Planta/química , Vapor
18.
Food Chem ; 147: 60-9, 2014 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-24206686

RESUMO

In the coming years, the frequency of unauthorised genetically modified organisms (GMOs) being present in the European food and feed chain will increase significantly. Therefore, we have developed a strategy to identify unauthorised GMOs containing a pCAMBIA family vector, frequently present in transgenic plants. This integrated approach is performed in two successive steps on Bt rice grains. First, the potential presence of unauthorised GMOs is assessed by the qPCR SYBR®Green technology targeting the terminator 35S pCAMBIA element. Second, its presence is confirmed via the characterisation of the junction between the transgenic cassette and the rice genome. To this end, a DNA walking strategy is applied using a first reverse primer followed by two semi-nested PCR rounds using primers that are each time nested to the previous reverse primer. This approach allows to rapidly identify the transgene flanking region and can easily be implemented by the enforcement laboratories.


Assuntos
Passeio de Cromossomo/métodos , Alimentos Geneticamente Modificados/normas , Oryza/genética , Plantas Geneticamente Modificadas/genética , Reação em Cadeia da Polimerase/métodos , Primers do DNA/genética
19.
N Biotechnol ; 31(2): 166-71, 2014 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-24308933

RESUMO

Risk assessment of genetically modified organisms (GMOs) remains a contentious area and a major factor influencing the adoption of agricultural biotech. Methodologically, in many countries, risk assessment is conducted by expert committees with little or no recourse to databases and expert systems that can facilitate the risk assessment process. In this paper we describe DTREEv2, a computer-based decision support system for the identification of hazards related to the introduction of GM-crops into the environment. DTREEv2 structures hazard identification and evaluation by means of an Event-Tree type of analysis. The system produces an output flagging identified hazards and potential risks. It is intended to be used for the preparation and evaluation of biosafety dossiers and, as such, its usefulness extends to researchers, risk assessors and regulators in government and industry.


Assuntos
Tomada de Decisões Assistida por Computador , Plantas Geneticamente Modificadas , Software , Medição de Risco/métodos
20.
J Sci Food Agric ; 93(9): 2146-53, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23408379

RESUMO

BACKGROUND: Leek is grown for its thickened cylindrical white shaft made up of long leaf bases. Despite the potentially valuable nutritional profile of the green leaves, a large portion remains unused owing its restricted culinary applications. This large quantity of this plant biomass could be valorized given an adequate stabilization method. In this study, we examined leek fermentation with regard to antioxidant changes. RESULTS: The oxygen radical absorbance capacity (ORAC) increased by 62% when the green leaves were fermented for 21 days, while 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity did not increase significantly. Fermentation resulted in an increase of endogenous polyphenolic compounds such as ferulic acid, astragalin, luteolin and naringenin. Moreover, fermentation stimulated the production of a series of polyphenolic compounds that were not present in the fresh leek. The flavour precursors in leek, i.e. methiin and isoalliin, were reduced by 91-93% and 100%, respectively, when spontaneous fermentation was allowed to occur on the white shaft and green leaves. CONCLUSION: Our results demonstrated that application of fermentation resulted in a higher ORAC value and polyphenol content of the leek plant, especially in the green leaves. These results indicate the nutritional relevance of fermentation, which hold promise as a stabilization technique.


Assuntos
Allium/química , Antioxidantes/análise , Flavonoides/análise , Conservação de Alimentos , Folhas de Planta/química , Caules de Planta/química , Allium/microbiologia , Antioxidantes/metabolismo , Bélgica , Ácidos Cumáricos/análise , Ácidos Cumáricos/metabolismo , Cisteína/análogos & derivados , Cisteína/análise , Cisteína/metabolismo , Fermentação , Flavanonas/análise , Flavanonas/metabolismo , Flavonoides/metabolismo , Alimentos Orgânicos/análise , Alimentos Orgânicos/economia , Indústria de Processamento de Alimentos/economia , Bactérias Gram-Negativas/metabolismo , Bactérias Gram-Positivas/metabolismo , Resíduos Industriais/análise , Resíduos Industriais/economia , Quempferóis/análise , Quempferóis/metabolismo , Luteolina/análise , Luteolina/metabolismo , Folhas de Planta/microbiologia , Caules de Planta/microbiologia , Sais/química
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