Evaluation of the thermal resistance of Salmonella Typhimurium ATCC 14028 after long-term blanched peanut kernel storage

Publication date: January 2020Source: LWT, Volume 117Author(s): A.A.M. Pereira, F.S. Prestes, A.C.M. Silva, M.S. NascimentoAbstractThe aim of this study was to evaluate the behavior of Salmonella Typhimurium ATCC 14028 during peanut dry roasting after pre-adaptation to desiccation stress. To cause desiccation stress, blanched peanut kernels (aw 0.43) were inoculated with S. Typhimurium and stored at 28 °C for up to 180 days. Then, the samples were roasted at 120 °C for 0, 10, 20 and 30 min. A concave upward curve for Salmonella population during the storage of blanched peanut kernels was observed, with reduction of up to 2.6 log cfu.g−1. Further, the storage time had an impact on the thermal resistance of S. Typhimurium during the dry roasting process. The non-stored peanut sample showed reductions of 1.8 and 3.2 log cfu.g−1, whereas in samples stored for 180 d the decrease in Salmonella count was 0.7 and 1.3 log cfu.g−1 after 20 and 30 min at 120 °C, respectively. In addition, according to the Weibull model, to reach 4 and 5-log reductions between 34.9 and 59.0 min and 40.3 and 68.0 min in stored samples were needed. Therefore, these results showed an increase in the thermal resistance of S. Typhimurium, from 30 days storage time, on blanched peanut kernels suggesting the presence of cross-resistance.
Source: LWT Food Science and Technology - Category: Food Science Source Type: research