Avaliação do comportamento de Salmonella enterica em produtos à base de grão-de-bico.

Abstract

The consumption of chickpeas (Cicer arietinum L.) and their product-based, such as hummus, has gradually increased, but in contrast to this popularization, there have been reports and notifications of outbreaks related to contamination of the product by the bacterial species Salmonella enterica. Therefore, the aim of this work was to study the behavior of three serotypes of S. enterica (S. Enteritidis-502, S. Typhimurium-272 and S. Senftenberg-S87) in chickpea products subjected to different preparation and storage conditions, using tools proposed from predictive microbiology. The growth of the pathogen was assessed in hummus with the inoculation of 3 log CFU/g in individual portions, stored at 15, 12, 10, 7, 4 °C for 10 days. Growth was evidenced at temperatures between 15 and 10 °C and the Baraniy and Roberts (BAR) primary model was used to obtain growth parameters. Between 15-10 °C, maximum population density values Nmax>7 log CFU/g were obtained and growth potentials (∆) ranged from 4.70±0.68 to 6.24±0.12 log CFU/g. Maximum growth rates (μmax) ranged from 0.191±0.087 to 0.020±0.06 h-1. The S. Senftenberg serotype obtained the highest μmax (0.191±0.087 h-1) at 15 °C and the lowest (0.020±0.06h-1) when stored at 10°C. The adaptation time (λ) ranged from 67.2±0.1 to 12.1±0.1 h, with the highest λ corresponding to S. Typhimurium when stored at 10 °C. The survival of the serotypes was evident when the hummus was stored at 4°C and 7°C and the growth potentials ranged from -2,56±0,93 to -0,52±0,39 log UFC/g. The survival of S. enterica in cooked chickpeas was assessed by individually inoculating 7 log CFU/g of the three serotypes, in which the samples were subjected to the roasting process at 4 different temperatures (100, 120, 150 e 180 °C) for 60 min. The primary Weibull model was used to obtain the survival parameters, where the results indicated the influence of temperature on the survival of the bacteria. The S. Enteritidis serotype survived roasting conditions between 100-150 °C, S. Typhimurium between 100 °C and 120 °C and S. Senftenberg at 100 °C. The thermal resistance of the three serotypes was evaluated by the D and z values, where the 4D value for heat treatments at 120 °C was 54.2±1.73 for S. Enteritidis, 53.4±4.24 for S. Typhimurium and 37.4±5.89 min for S. Senftenberg. The z values (temperature coefficient) obtained in the experiment were 94.07, 70.87 and 83.77 °C for S. Enteritidis, S. Typhimurium and S. Senftenberg, respectively. In this view, this study provides a knowledge of the impacts on the processing of chickpea-based products and related to the growth conditions of different serotypes of Salmonella enterica, thus contributing to the establishment of measures to control the growth of the pathogen and the adoption of effective measures for product safety.