Effect of moisture on salmonella spp. heat resistance in cocoa and hazelnut shells

The heat resistance of food-poisoning outbreak and non-outbreak associated strains of Salmonella (S. Enteritidis, S. Montevideo, S. Napoli, S. Oranienburg, S. Poona, S. Senftenberg and S. Typhimurium) was established in confectionery-related materials such as crushed cocoa bean and hazelnut shells at low moisture contents (<= 4% w/w). The two most heat resistant strains in cocoa and hazelnut shells at ca. 4% w/w moisture were S. Oranienburg and S. Enteritidis PT30. Both strains were associated with outbreaks from dried materials. Their D-100 degrees C values were ca. 2.5 min in crushed cocoa bean shells and 7-11 min in crushed hazelnut shells. Addition of moisture to ca. 7% w/w markedly reduced D-values (D-80 degrees C of 2-4.5 min) for both strains in the two matrices. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.