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Impact of peanut roasting on Salmonella spp. survival

Prestes, Flávia Souza, da Silva, Astrid Caroline Muniz, Pereira, André Aquino Mariano, Nascimento, Maristela da Silva do
Lebensmittel-Wissenschaft + [i.e. und] Technologie 2019 v.108 pp. 168-173
Salmonella, Weibull statistics, heat inactivation, heat tolerance, oils, pathogens, peanuts, roasting, serotypes, supply chain, temperature
This study evaluated the efficiency of the dry and oil roasting processes in the inactivation of a pool of five serotypes of Salmonella isolated from the peanut supply chain (Miami, Muenster, Yoruba, Javiana and Glostrup). The Weibull model was fitted to the data to describe the thermal inactivation of Salmonella in peanut matrices. The time to achieve 5-log reduction of the pathogen during dry roasting at 125 °C was significantly different between the matrices (p < 0.05), being 1.5-fold more on the blanched peanuts than on the in-shell peanuts. Only the 145 and 160 °C protocols resulted in reductions > 5-log MPN/g of Salmonella for both matrices, with T5d of 56 and 39 min for blanched peanuts and 46 and 44 min for in-shell peanuts, respectively. For the oil roasting, the Weibull model predicted the first decimal reduction after 7.2 s and 0.012 s at 115 °C and 145 °C, respectively. To achieve reduction of 5 log Salmonella it would take 3.0 min at 115 °C, and 0.40 min at 145 °C. The results demonstrated that temperature, heat process and in some cases the type of matrix influence the thermal resistance of Salmonella on peanuts.