Researchers from the U.S. Department of Agriculture’s Agricultural Research Service (ARS) are examining the use of infrared heat and hot air to pasteurize almonds. The method eliminates pathogens such as Salmonella enterica.
Nuts aren’t an ingredient we’d normally think of when it comes to food safety. But raw almonds have been the source of two foodborne illness outbreaks since 2001, and the California Almond Board has required treatment for almonds since 2007. In January 2012, Federal Judge Ellen Segal Huvelle ruled that the U.S. Agriculture rule about pasteurization of raw almonds must stand.
Infrared heat is the breakthrough in the new method. It reduces the roasting time while heating the almonds to the point where 99.99% of bacteria are eliminated. The methods currently used for pasteurizing almonds include oil roasting, dry roasting, blanching, steam processing, and a wash with propylene oxide (PPO).
All of those methods are less environmentally friendly than infrared heat, although they have been tested by the FDA and approved by the EPA as “posing no health risk”. Steam and PPO methods only treat the surface of the nut.
The USDA is going to work with California almond processors to scale the method for commercial use.
