INACTIVATION PROFILE OF Salmonella enterica IN ROASTED CHICKPEAS UNDER DIFFERENT TEMPERATURE CONDITIONS

Roasted chickpeas have gained popularity for their crunchiness and nutritional value. However, pathogens such as Salmonella enterica can survive heat treatments during processing. Thus, this study assessed the impact of roasting temperatures at 100, 120, 150 and 180 °C for 60 minutes, on S. Senftenberg, S. Typhimurium and S. Enteritidis inactivation parameters. Each strain was inoculated separately at ca. of 7 log CFU/g in cooked chickpeas. Samples were collected at times 0, 5, 10, 15, 30, 45 and 60 min. The Salmonella population was enumerated in SS agar and incubated at 37 °C for 24 hours. The counts were fitted by the Weibull model to estimate the inactivation parameters. For each serotype, the first decimal reduction (δ; min), the shape parameter (p), and time to 4 decimal reductions (4D; min) were estimated. The log decimal reduction (γ) was also calculated using the difference between initial and final observed counts. The temperature coefficient (z) was determined by linear regression of temperature versus log δ. The δ-values ranging from 50.10 to 0.55 min for S. Enteritidis, from 38.56 to 1.91 min S. Typhimurium, and from 41.85 to 5.83 min for, S. Senftenberg. For roasting performed at 100 and 120 °C, S. Enteritidis and S. Senftenberg showed downward concavity curves (p > 1). In contrast, at 150 and 180 °C curves concavities were upward (p < 1). At 100 °C, γ-value was lower than 2.00 log CFU/g for all tested serotypes. At 120 °C, S. Senftenberg reduced by 6.9 log decimal reduction, while S. Enteritidis and S. Typhimurium showed γ-values of 4.19 and 3.86 log CFU/g, respectively. Meanwhile, at 150 °C, S. Typhimurium and S. Senftenberg were inactivated, whereas S. Enteritidis showed a reduction of 3.36 log CFU/g. Yet, at 180 °C, after 45 min, all serotypes were below the detection limit. The 4D-values ranged from 13.2 to 54.6 min for roasting temperatures of 120 and 180 °C. A higher 4D-value was observed at 120 °C for S. Enteritidis and S. Typhimurium, 54.6 min. The z-values were 44.5, 65.6 and 103.1 °C for S. Typhimurium, S. Enteritidis, and S. Senftenberg, respectively. These results highlight differences in thermal resistance among serotypes. S. Typhimurium was more easily inactivated by heat, unlike S. Enteritidis, which required higher temperatures or longer exposure times. Understanding the thermal behaviour of Salmonella during chickpea roasting is essential to ensure microbiological safety and to establish evidence-based processing parameters.