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Titre : Calidad sanitaria en la producción de nopal verdura (Opuntia sp.) en Otumba, México

SANITARY QUALITY OF CACTUS LEAVES (Opuntia sp.) PRODUCTION IN OTUMBA, MÉXICO

Auteur : Martínez Martínez, Talina Olivia

Université de soutenance : Colegio de Postgraduados (COLPOS) Consejo Nacional de Ciencia y Tecnología (CONACYT)

Grade : Doctorado en Ciencias, especialista en Entomología y Acarología 2011

Résumé
The sanitary quality of horticultural products should be considered a priority in food production. In Mexico, there is a great concern from producers association and gubernamental authorities to implement production systems for reducing contamination risks (SRCR). However, for the implementation of this systems is required to do several requirements, one them, is the process validation. An immediate way to perform this requirement is the evaluation of the sanitary quality (microbiological and toxicology assessment), for this reason, is necessary a sampling plan and appropriate techniques for pathogen detection and quantification of indicators. For this purpose, in this study was determined the sanitary quality of nopal, which was produced under a SRCR, through aerobic mesophilic bacteria and total coliforms counts, Salmonella sp. and Escherichia coli detection, and pesticide residues determination (organochlorine, organophosphorus, organonitrogen and pyrethroid). The results were : mesophilic bacteria and total coliform levels were within the permissible, Salmonella was not detected, but Escherichia coli was detected. Bifenthrin, dimethoate, omethoate, chlorpyrifos ethyl, malathion and methyl parathion were detected, these pesticides are not allowed. On the other hand, was assessed the survival capacity of Salmonella and E. coli in peeled and whit spines cactus leaves at two temperatures (4 and 18 ° C) for 16 days, in order to determine the bacterias behavior once they have invaded nopal tissue, under common management and market storage. Salmonella and E. coli survived in this conditions, although the major survival was in peeled pads Later, phenolic compounds with potential microbicide in nopal was identified and quantified, (protochatequic and caffeic acids were the principal compounds. In this paper, we present a proposal to select a sample size for microbiological analysis, using two and three classes sampling and protection consumer level and the producer’s quality level. Both sampling design allowed to obtain sampling schemes with a level of protection required by the market and to do statistically comparations between different systems of production of horticultural

Mots clés : Salmonella ; Escherichia coli ; Pesticides ; Phenolic compounds ; Survival ; Sample size ; Entomología y Acarología

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