Evaluación de un producto a base de ácidos orgánicos frente a E. coli y Salmonella spp, en la desinfección de lechuga fresca
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Date
2012
Journal Title
Journal ISSN
Volume Title
Publisher
Corporación Universitaria Lasallista
Abstract
Introduction. Fresh fruits and vegetables are an essential
component of many people´s diet worldwide
and their consumption is increasing, due to several
factors such as the tendency towards healthier food
consumption. Organic acids appear as an alternative
to replace chloride in the disinfection of these
products, given their good antimicrobial performance
and their condition as GRAS (Generally Recognized
as Safe). Objective. Determining the E. coliand Salmonella spp´s reduction in Batavia lettuce
(Lactuca sativa), by the use of a product based on
organic acids. Materials and methods. Lettuce
samples were inoculated with known concentrations
ofSalmonella enteritidis ATCC 13076 and Salmonella
typhimurium ATCC 14028 and E. coli ATCC 8739
y ATCC 25922, which were put before solutions of
the product (organic acid) at 1000, 1200 and 2000
ppm during three exposition periods. They were later
neutralized with a Letheen broth solution and analyzed
by means of on plate accounts. Contaminated
samples of not disinfected lettuce were taken as positive
controls. The effectiveness of the disinfection
was evaluated by analyzing the logarithmic reduction
of the microbial population during the time of exposition
to the disinfectant, in different concentrations
of the active principle. Results. Reductions above
99% were obtained for the lettuce samples inoculated
with E. coli Salmonella spp. In the lettuces inoculated
with E. coli, the reduction of the population
reached 2.09 ± 0.14 Log UFC/g, while the reduction
of Salmonella spp was 0.98 ± 0.19 Log UFC/g. The
study revealed that the most effective treatment under
antimicrobial terms before high populations (105
UFC/g) of the pathogens inoculated was that with
a 2000 ppm concentration and a 5 minutes contact
time. Conclusion. The in vitro and the inoculation
tests demonstrated that E. coli is more sensitive to
the disinfection treatment than Salmonella spp. The
disinfectant based on organic acids is an effective
and safe alternative to reduce pathogen microorganisms
in vegetables, reducing the microbiological
hazard associated to such products, which are
usually eaten raw.
Description
Keywords
Corporación Universitaria Lasallista, Lechuga, Salmonella, Ácidos orgánicos, Conservación de alimentos, Inocuidad de los alimentos