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Prado-Silva L.,University of Campinas | Cadavez V.,Polytechnic Institute of Braganza IPB | Gonzales-Barron U.,Polytechnic Institute of Braganza IPB | Rezende A.B.,University of Campinas | Sant'Ana A.S.,University of Campinas
Applied and Environmental Microbiology

The aim of this study was to perform a meta-analysis of the effects of sanitizing treatments of fresh produce on Salmonella spp., Escherichia coli O157:H7, and Listeria monocytogenes. From 55 primary studies found to report on such effects, 40 were selected based on specific criteria, leading to more than 1,000 data on mean log reductions of these three bacterial pathogens impairing the safety of fresh produce. Data were partitioned to build three meta-analytical models that could allow the assessment of differences in mean log reductions among pathogens, fresh produce, and sanitizers. Moderating variables assessed in the meta-analytical models included type of fresh produce, type of sanitizer, concentration, and treatment time and temperature. Further, a proposal was done to classify the sanitizers according to bactericidal efficacy by means of a meta-analytical dendrogram. The results indicated that both time and temperature significantly affected the mean log reductions of the sanitizing treatment (P < 0.0001). In general, sanitizer treatments led to lower mean log reductions when applied to leafy greens (for example, 0.68 log reductions [0.00 to 1.37] achieved in lettuce) compared to other, nonleafy vegetables (for example, 3.04 mean log reductions [2.32 to 3.76] obtained for carrots). Among the pathogens, E. coli O157:H7 was more resistant to ozone (1.6 mean log reductions), while L. monocytogenes and Salmonella presented high resistance to organic acids, such as citric acid, acetic acid, and lactic acid (~3.0 mean log reductions). With regard to the sanitizers, it has been found that slightly acidic electrolyzed water, acidified sodium chlorite, and the gaseous chlorine dioxide clustered together, indicating that they possessed the strongest bactericidal effect. The results reported seem to be an important achievement for advancing the global understanding of the effectiveness of sanitizers for microbial safety of fresh produce. © 2015, American Society for Microbiology. Source

Silva L.P.,University of Campinas | Gonzales-Barron U.,Polytechnic Institute of Braganza IPB | Cadavez V.,Polytechnic Institute of Braganza IPB | Sant'Ana A.S.,University of Campinas
Food Microbiology

In this work, all publicly-accessible published findings on Alicyclobacillus acidoterrestris heat resistance in fruit beverages as affected by temperature and pH were compiled. Then, study characteristics (protocols, fruit and variety, °Brix, pH, temperature, heating medium, culture medium, inactivation method, strains, etc.) were extracted from the primary studies, and some of them incorporated to a meta-analysis mixed-effects linear model based on the basic Bigelow equation describing the heat resistance parameters of this bacterium. The model estimated mean D* values (time needed for one log reduction at a temperature of 95°C and a pH of 3.5) of Alicyclobacillus in beverages of different fruits, two different concentration types, with and without bacteriocins, and with and without clarification. The zT (temperature change needed to cause one log reduction in D-values) estimated by the meta-analysis model were compared to those ('observed' zT values) reported in the primary studies, and in all cases they were within the confidence intervals of the model. The model was capable of predicting the heat resistance parameters of Alicyclobacillus in fruit beverages beyond the types available in the meta-analytical data. It is expected that the compilation of the thermal resistance of Alicyclobacillus in fruit beverages, carried out in this study, will be of utility to food quality managers in the determination or validation of the lethality of their current heat treatment processes. © 2014 Elsevier Ltd. Source

Gonzales-Barron U.,Polytechnic Institute of Braganza IPB | Piza L.,University of Sao Paulo | Xavier C.,Polytechnic Institute of Braganza IPB | Costa E.,University of Sao Paulo | Cadavez V.,Polytechnic Institute of Braganza IPB
Food Science and Technology International

Beef cattle carrying Salmonella spp. represents a risk for contamination of meat and meat products. This study aimed to build an exposure assessment model elucidating the changes in Salmonella prevalence in Brazilian beef along the processing stages. To this effect, the results of a number of published studies reporting Salmonella incidences were assembled in order to model conversion factors based on beta distributions representing the effect of every production stage on the Salmonella incidence on beef carcasses. A random-effects meta-analysis modelled the hide-to-carcass transfer of Salmonella contamination. The Monte Carlo simulation estimated the Salmonella prevalence in beef cuts from processing plants to be â∼1/46.1% (95% CI: 1.4-17.7%), which was in reasonable agreement with a pool (n = 105) of surveys' data of Salmonella in Brazilian beef cuts (mean 4.9%; 95% CI: 1.8-11.5%) carried out in commercial establishments. The results not only underscored the significant increase in Salmonella prevalence that can occur during evisceration/splitting and boning but also reinforced that, when hygienic slaughter procedures are properly implemented, the load of Salmonella can be reduced at dehiding, rinsing and chilling. As the model was based on a systematic review and meta-analysis, it synthesised all available knowledge on the incidence of Salmonella in Brazilian beef. © 2015 The Author(s). Source

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