Salmonella contamination can occur at any point in handling and processing of peanuts and is usually traced back to human or animal sources. To help mitigate the risks associated with product contamination, a study conducted jointly by Bühler Aeroglide and the USDA, Agricultural Research Service has verified that processors of peanuts can use industrially relevant parameters in the dry roasting process for acceptable salmonella reduction.

Published in Peanut Science, Bühler Aeroglide, Cary, N.C., reportedly offers the first study to predict log reductions in peanut dry roasting using industrial dry roasting parameters. The roaster simulated the parameters of Bühler Aeroglide's AeroRoast industrial peanut roaster. The study provides scientific documentation for reducing salmonella in real-world conditions for dry roasting peanuts. The abstract can be found at http://www.peanutscience.com/doi/abs/10.3146/PS13-21.1

In order to determine the reduction of salmonella in a specific set of roaster conditions, peanut processors use challenge tests, which are usually performed in conjunction with testing laboratories such as Deibel Labs or JLA Global. Sample mesh bags of product inoculated with a salmonella surrogate are passed through the roaster and organism reduction is determined. A peanut processor can easily spend $5,000 to $8,000 per test and multiple tests may be required to validate equipment.

The study will help processors determine appropriate roaster conditions before validation and thus significantly reduce the number of iterations and hence the cost of validating their equipment, says Bühler Aeroglide.

Dan Poirier, a process engineer at the company, led the study using a laboratory scale roaster at the company's technical center. Research Leader Tim Sanders, Ph.D., and Food Technologist Jack Davis, Ph.D., of the USDA Agricultural Research Service at North Carolina State University in the Department of Food, Bioprocessing and Nutrition Sciences in Raleigh, N.C., contributed to the study.