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Microbiological and Chemical Quality of Portuguese Lettuce—Results of a Case Study

In addition to environmental pollution issues, social concerns about the sustainability, safety, and quality of conventionally grown fruits and vegetables have been increasing. In order to evaluate if there were any microbiological differences between samples of organic and conventional lettuce, a w...

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Autores principales: Ferreira, Catarina, Lopes, Filipa, Costa, Reginaldo, Komora, Norton, Ferreira, Vânia, Cruz Fernandes, Virgínia, Delerue-Matos, Cristina, Teixeira, Paula
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7555633/
https://www.ncbi.nlm.nih.gov/pubmed/32932798
http://dx.doi.org/10.3390/foods9091274
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author Ferreira, Catarina
Lopes, Filipa
Costa, Reginaldo
Komora, Norton
Ferreira, Vânia
Cruz Fernandes, Virgínia
Delerue-Matos, Cristina
Teixeira, Paula
author_facet Ferreira, Catarina
Lopes, Filipa
Costa, Reginaldo
Komora, Norton
Ferreira, Vânia
Cruz Fernandes, Virgínia
Delerue-Matos, Cristina
Teixeira, Paula
author_sort Ferreira, Catarina
collection PubMed
description In addition to environmental pollution issues, social concerns about the sustainability, safety, and quality of conventionally grown fruits and vegetables have been increasing. In order to evaluate if there were any microbiological differences between samples of organic and conventional lettuce, a wide range of parameters were tested, including pathogens and indicator organisms: the enumeration of Escherichia coli; the detection of Salmonella spp.; the detection/enumeration of Listeria monocytogenes; the enumeration of lactic acid bacteria, Pseudomonas spp. yeasts and molds, and Enterobacteriaceae. This study also evaluated the chemical safety of the lettuce samples, quantifying the nitrate concentration and 20 pesticides (14 organochlorine and 6 organophosphorus pesticides). Significant differences (p < 0.05) between the conventional and organic samples were only detected for the counts of total microorganisms at 30 °C. Pathogens were absent in all the samples. The analytical method, using the quick, easy, cheap, effective, rugged, and safe (QuEChERS) approach for pesticide extraction, was suitable for detecting the targeted analytes; the limit of quantification (LOQ) was between 0.6 and 1.8 µg/kg (lower than the Maximum Residue Levels (MRLs) established by EU legislation). In three organic lettuce samples, one organochlorine pesticide (α-HCH) was observed below the MRLs. For the samples analyzed and for the parameters investigated, except for the total mesophilic counts, the organic and conventional lettuces were not different.
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spelling pubmed-75556332020-10-19 Microbiological and Chemical Quality of Portuguese Lettuce—Results of a Case Study Ferreira, Catarina Lopes, Filipa Costa, Reginaldo Komora, Norton Ferreira, Vânia Cruz Fernandes, Virgínia Delerue-Matos, Cristina Teixeira, Paula Foods Communication In addition to environmental pollution issues, social concerns about the sustainability, safety, and quality of conventionally grown fruits and vegetables have been increasing. In order to evaluate if there were any microbiological differences between samples of organic and conventional lettuce, a wide range of parameters were tested, including pathogens and indicator organisms: the enumeration of Escherichia coli; the detection of Salmonella spp.; the detection/enumeration of Listeria monocytogenes; the enumeration of lactic acid bacteria, Pseudomonas spp. yeasts and molds, and Enterobacteriaceae. This study also evaluated the chemical safety of the lettuce samples, quantifying the nitrate concentration and 20 pesticides (14 organochlorine and 6 organophosphorus pesticides). Significant differences (p < 0.05) between the conventional and organic samples were only detected for the counts of total microorganisms at 30 °C. Pathogens were absent in all the samples. The analytical method, using the quick, easy, cheap, effective, rugged, and safe (QuEChERS) approach for pesticide extraction, was suitable for detecting the targeted analytes; the limit of quantification (LOQ) was between 0.6 and 1.8 µg/kg (lower than the Maximum Residue Levels (MRLs) established by EU legislation). In three organic lettuce samples, one organochlorine pesticide (α-HCH) was observed below the MRLs. For the samples analyzed and for the parameters investigated, except for the total mesophilic counts, the organic and conventional lettuces were not different. MDPI 2020-09-11 /pmc/articles/PMC7555633/ /pubmed/32932798 http://dx.doi.org/10.3390/foods9091274 Text en © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Communication
Ferreira, Catarina
Lopes, Filipa
Costa, Reginaldo
Komora, Norton
Ferreira, Vânia
Cruz Fernandes, Virgínia
Delerue-Matos, Cristina
Teixeira, Paula
Microbiological and Chemical Quality of Portuguese Lettuce—Results of a Case Study
title Microbiological and Chemical Quality of Portuguese Lettuce—Results of a Case Study
title_full Microbiological and Chemical Quality of Portuguese Lettuce—Results of a Case Study
title_fullStr Microbiological and Chemical Quality of Portuguese Lettuce—Results of a Case Study
title_full_unstemmed Microbiological and Chemical Quality of Portuguese Lettuce—Results of a Case Study
title_short Microbiological and Chemical Quality of Portuguese Lettuce—Results of a Case Study
title_sort microbiological and chemical quality of portuguese lettuce—results of a case study
topic Communication
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7555633/
https://www.ncbi.nlm.nih.gov/pubmed/32932798
http://dx.doi.org/10.3390/foods9091274
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