Person:
García Lacarra, Teresa

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First Name
Teresa
Last Name
García Lacarra
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Veterinaria
Department
Nutrición y Ciencia de los Alimentos
Area
Nutrición y Bromatología
Identifiers
UCM identifierORCIDScopus Author IDWeb of Science ResearcherIDDialnet IDGoogle Scholar ID

Search Results

Now showing 1 - 10 of 23
  • Publication
    A sensitive and specific real-time PCR targeting DNA from wheat, barley and rye to track gluten contamination in marketed foods
    (ELSEVIER, 2019-11) Sohrabi, v; Cruz, Silvia de la; García García, Aina; Madrid García, Raquel; García Lacarra, Teresa; Martín De Santos, María Del Rosario; González Alonso, María Isabel
    This work reports a real-time PCR assay to specifically detect the presence of DNA from the main gluten-containing cereals wheat, barley and rye (WBR) in foodstuffs. The WBR real-time PCR uses two specific primers and a Taqman probe for amplification of a 118 bp DNA fragment common to the three target cereals on the ribosomal internal transcribed spacer (ITS) region. In-house validation of the method was performed employing three binary arrays containing different concentrations (100 000–10 mg/kg) of a wheat/barley/rye mixture in maize flour: untreated, soft heat-treated at 160 °C/13 min and intense heat-treated at 200 °C/20 min. Results showed optimal PCR amplification efficiency, reproducibility and sensitivity with an overall limit of detection of 10–50 mg/kg of the target cereals, theoretically equating to approximately 1–5 mg/kg of gluten. Applicability of the assay was further assessed through a market analysis of 220 food products by the real-time PCR assay and the official R5-based ELISA. Comparative results highlighted the ability of the proposed methodology as a highly sensitive and robust procedure to detect the presence of potentially harmful concentrations of undeclared gluten-containing cereals in some of the tested samples, supporting results of the immunological assays currently used for gluten determination in foods.
  • Publication
    Development of real-time PCR assays to detect cashew (Anacardium occidentale) and macadamia (Macadamia intergrifolia) residues in market analysis of processed food products
    (ELSEVIER, 2015-06) López-Calleja, Inés María; Cruz, Silvia de la; González Alonso, María Isabel; García Lacarra, Teresa; Martín De Santos, María Del Rosario
    Real-time polymerase chain reaction (PCR)-based assays for detection of cashew (Anacardium occidentale) and macadamia nut (Macadamia intergrifolia) traces in food products are described here. The real time PCR technique proposed herein were developed based on the design of macadamia and cashew-specific primers from the ITS region and a TaqMan fluorescent probe. The methods were positive for cashew and macadamia respectively, and negative for all other heterologous plant and animal species tested. Using a series of model samples with defined levels of raw and heat-treated cashew and macadamia nut, respectively, within a range of concentrations of 0.1–100 000 mg kg−1, practical detection limits of 0.1 mg kg−1 for cashew and macadamia nut were estimated. Practical applicability of the PCR methods was tested by the analysis of a total of 214 commercial foodstuffs. These PCR methods, are useful for highly selective, and sensitive detection of traces of macadamia and cashew nuts in commercial food products and is therefore proposed as a ready-to-use analytical tool to trace these target allergens in foods.
  • Publication
    PCR-based assay for the detection of Alternaria species and correlation with HPLC determination of altenuene, alternariol and alternariol monomethyl ether production in tomato products
    (ELSEVIER, 2012-05) Pavón, Miguel Ángel; Luna, Agustín; Cruz, Silvia de la; González Alonso, María Isabel; Martín De Santos, María Del Rosario; García Lacarra, Teresa
    Alternaria spp. contamination and subsequent production of mycotoxins is a common problem in vegetable crops. Identification of Alternaria species by traditional methods requires specific skills and may not detect toxigenic moulds inactivated by food processing. By using molecular methods such as PCR the detection of Alternaria spp. becomes possible directly from the food or feed samples. In this study, a PCR method based on the Internal Transcribed Spacer (ITS) genetic marker has been used for detection of Alternaria spp. in raw and processed commercial tomato samples. Occurrence of altenuene, alternariol and alternariol methyl ether in the samples was analysed by high-performance liquid chromatography (HPLC) in order to assess the ability of the PCR assay to identify tomato samples containing Alternaria mycotoxins. The PCR assay revealed the presence of Alternaria spp. DNA in 41 out of 90 commercial samples (45.6%), while HPLC detected at least one of the Alternaria mycotoxins within 31 of the PCR positive samples. Detection of Alternaria DNA correlated well with the presence of the analysed Alternaria mycotoxins, indicating that the PCR protocol developed in this work for detection of Alternaria spp. DNA could be used as an indirect marker of the presence of Alternaria mycotoxins in raw and processed tomato products.
  • Publication
    Duplex real-time PCR using TaqMan® for the detection of sunflower (Helianthus annuus) and poppy (Papaver rhoeas) in commercial food products
    (ELSEVIER, 2015-09-15) López-Calleja, Inés María; Cruz, Silvia de la; González Alonso, María Isabel; García Lacarra, Teresa; Martín De Santos, María Del Rosario
    The paper presents a duplex real-time PCR assay for the simultaneous detection of traces of potentially allergenic sunflower and poppy seeds in commercial food products. For the design of sunflower and poppy-specific primers and two TaqMan fluorescent probes labeled with FAM and HEX respectively, the ITS1 region was selected. The duplex real-time PCR assay did not show any cross-reactivity for all other heterologous plant and animal species tested commonly used in the food industry. Analysis of serially diluted raw and heat-treated sunflower in poppy with a range of concentrations of 0.1–100,000 mg kg−1 and raw and heat-treated poppy in sunflower with the same concentrations resulted in good linearity, with a LOD of 0.1 mg kg−1 of sunflower and poppy content. The duplex real-time PCR assay was applied to verify correct labeling of 238 commercial foodstuffs comprising: nut bars, cookies, chocolates, creams, bonbons, cereals, bread, ice cream, meat products and prepared food products. Results indicate that this duplex PCR is highly sensitive and selective, which makes it suitable for the detection of sunflower and poppy traces in food samples. In addition, it can be useful for monitoring the effectiveness of cleaning processes in the production units of the food industry.
  • Publication
    Survey of undeclared allergenic pistachio (Pistacia vera) in commercial foods by hydrolysis probe real-time PCR
    (ELSEVIER, 2014-05) López-Calleja, Inés María; Cruz, Silvia de la; González Alonso, María Isabel; García Lacarra, Teresa; Martín De Santos, María Del Rosario
    Tree nut allergies represent an important health problem in industrialized countries. Among these, pistachio (Pistacia vera) kernels which are consumed as snack foods and used as ingredients in confectionery, chocolates, meat products, and ice-cream industries have been reported to cause IgE-mediated allergic reactions. Trace amounts of undeclared pistachio allergens can cause serious health risks for food-allergic consumers. In order to provide an appropriate method for the detection of pistachio in food products, a real-time polymerase chain reaction (PCR) system for the specific and sensitive detection of pistachio was developed. The sensitivity was investigated on spiked wheat flour samples with defined raw and heat-treated pistachio contents (0.1–100,000 mg/kg). The real-time PCR detected pistachio in these mixtures down to the lowest investigated spike level of 0.1 mg/kg. In addition, analysis of different retail samples from the market was performed to demonstrate the suitability of the assay in the food industry. The real-time PCR results obtained from the analysis of 229 commercial food products revealed 29 that didn't declare pistachio or traces on the label but were found to contain pistachio. The presented real time PCR method is useful for relatively fast, highly selective, and sensitive detection of pistachio in food samples.
  • Publication
    Development of a real time PCR assay for detection of allergenic trace amounts of peanut (Arachis hypogaea) in processed foods
    (ELSEVIER, 2013-04-01) López-Calleja, Inés María; Cruz, Silvia de la; Pegels, Nicolette; González Alonso, María Isabel; García Lacarra, Teresa; Martín De Santos, María Del Rosario
    Peanut allergic reactions can result from the ingestion of even very small quantities of peanut and represent a severe threat to the health of sensitized individuals. In order to protect the allergic consumer, efficient and reliable methods are required for the detection of allergenic ingredients. For this purpose, we have developed a TaqMan real-time PCR method for specific detection of peanut in commercial food products. The assay uses two genetic makers in the Arah2 (125 bp) and ITS1 (90 bp) gene respectively, and TaqMan probes. The nuclear 18S rRNA gene was employed as a positive amplification control. Results obtained on sensitivity of both Arah2 and ITS primers with mixtures spiked with different concentrations of the target showed detection levels of 10 and 0.1 ppm, respectively. The applicability of the real-time PCR protocol to detect the presence of peanut DNA in commercial food products was determined through analysis of 123 different commercial products with the ITS primers which aimed higher sensitivity than Arah2 primer pair. The performance of the real-time PCR proposed herein allows a highly sensitive detection of peanut DNA in all the different food products, which declared to contain peanut material as well as in others were the presence of peanut or its traces wasn't declared in the labeling.
  • Publication
    Duplex real-time PCR method for the detection of sesame (Sesamum indicum) and flaxseed (Linum usitatissimum) DNA in processed food products
    (Taylor & Francis Online, 2015-07-28) López-Calleja, Inés María; Cruz, Silvia de la; Martín De Santos, María Del Rosario; González Alonso, María Isabel; García Lacarra, Teresa
    The development of a duplex real-time polymerase chain reaction (PCR) method allowing the simultaneous detection of sesame and flaxseed DNA in commercial food products is described. This duplex real-time PCR technique is based in the design of sesame- and flaxseed-specific primers based on the ITS1 region and two TaqMan fluorescent probes. The method was positive for sesame and flaxseed, and showed no cross-reactivity for all other heterologous plant and animal species tested. Sesame and flaxseed could be detected in a series of model samples with defined raw and heat-treated sesame in flaxseed, and flaxseed in sesame, respectively, with detection limits of 1.3 mg kg(-1) for sesame and 1.4 mg kg(-1) for flaxseed. The applicability of the assay for determining sesame and flaxseed in different food matrices was investigated by analysing a total of 238 commercial foodstuffs. This PCR method is useful for highly selective and sensitive detection of traces of sesame and flaxseed in commercial food products.
  • Publication
    A novel approach to produce phage single domain antibody fragments for the detection of gluten in foods
    (ELSEVIER, 2020-06) García García, Aina; García Lacarra, Teresa; Martín De Santos, María Del Rosario; González Alonso, María Isabel; Madrid García, Raquel
    In this study, we demonstrated the feasibility of isolating recombinant phage-antibodies against gluten from a non-immunized library of human single-domain antibodies (dAbs). Phage display technology enabled the selection of affinity probes by successive rounds of biopanning against a biotinylated synthetic peptide comprising repetitive immunogenic gluten motifs. The analysis of a wide representation of heterologous plant species corroborated that two of the isolated clones were specific to wheat, barley and rye proteins. The phage antibody selected as the most appropriate clone for the detection of gluten in foods (dAb8E-phage) was further applied in an indirect ELISA to the analysis of 50 commercial food samples. Although the limit of detection achieved did not improve those of current immunoassays, the proposed methodology could provide promising new pathways for the generation of recombinant antibodies that allow a comprehensive determination of gluten in foods, whilst replacing the need for animal immunization.
  • Publication
    TaqMan real-time PCR assay for detection of traces of Brazil nut (Bertholletia excelsa) in food products
    (Elsevier, 2013-01-23) Cruz, Silvia de la; López-Calleja, Inés María; Alcocer, Marcos; González Alonso, María Isabel; Martín De Santos, María Del Rosario; García Lacarra, Teresa
    Mislabeling of food products containing Brazil nut may represent a serious thread for allergic consumers. In order to protect sensitized individuals, reliable methods to detect trace amounts of Brazil nut must be accessible to food industry as well as Food Safety authorities. According to this, a TaqMan real-time polymerase chain reaction (PCR) method has been developed for specific detection of Brazil nut in foodstuffs. The method employs Brazil nut specific primers and probe, targeting 2S albumin gene (Ber e 1), and a positive amplification control based on 18S rRNA gene. Results obtained on sensitivity with wheat flour spiked with different concentrations of raw and heat treated Brazil nut showed that the limit of detection (LOD) for the technique was 2.5 mg/kg. Applicability of the Brazil nut specific system was assessed through analysis of 66 different commercial food samples. The reported real-time PCR assay provides a useful tool for detection of Brazil nut DNA, and it can be used as a routine analysis to assert accuracy on food labeling.
  • Publication
    Multiplex ligation-dependent probe amplification (MLPA) for simultaneous detection of DNA from sunflower, poppy, flaxseed, sesame and soy allergenic ingredients in commercial food products
    (ELSEVIER SCI LTD, 2017-06-14) López Calleja, Inés; García García, Aina; Madrid García, Raquel; García Lacarra, Teresa; Martín De Santos, María Del Rosario; González Alonso, María Isabel
    This work describes a multiplex ligation-dependent probe amplification (MLPA) technique for the simultaneous detection of five food allergens: sunflower, poppy, flaxseed, sesame and soy. Species-specific MLPA half-probes were designed to detect the DNA from the targeted species. Ligated probes were amplified by polymerase chain reaction (PCR) and amplicons were detected using capillary electrophoresis. The specificity of the MLPA system was assessed against DNA from more than 50 plant and animal species. The limit of detection (LOD) of the assay was determined to be 10 mg/kg in a model cookie experimentally spiked with different concentrations of the target species. The applicability of the MLPA was demonstrated through the analysis of 56 different commercial products (breads, pastries, cereals, chocolates, drinks, etc.), evidencing the presence of one or more undeclared allergenic ingredients in some of the tested samples. Real-time PCR assays were also performed to confirm and complement MLPA results. The MLPA technique has proved as a qualified screening tool for determining the presence of low amounts of sunflower, poppy, flaxseed, sesame and soy in processed foods.