Thermal processes for nuts include oil roasting, dry roasting, and blanching as more traditional practices, but heat can also be applied through steam, infrared heat, and other means. Pasteurization has been successfully applied to raw almonds to reduce the presence of Salmonella. Some emerging technologies for LMFs include radio frequency and microwave heating, nonthermal plasma, pulsed light, UV light, irradiation, propylene oxide, ozone, and novel drying technologies such as microwave drying, vacuum drying, super-heated steam drying, infrared drying, and freeze drying. Although high-pressure processing has been successfully applied to high moisture foods, efficacy in LMFs is not well understood. Additional research is needed to understand these technologies’ application to LMFs.
Pathogen Detection Technologies and LMFs
Eliminating or preventing pathogens entering the production process through raw material screening and finished product testing are key to ensuring safe product is delivered. Unfortunately, processes that rely on inadequate or incorrectly used technologies can thwart a lot of well-meaning work.
High-performing pathogen testing technologies are able to identify intact pathogens, as well as pathogen cells that may have been damaged by freezing, drying, antimicrobial treatments, or other processing conditions. Pathogen detection methods typically require an enrichment step to allow bacteria to grow to detectable levels, and this nourishment and recovery step is especially critical for LMFs. Pathogens in these foods can be severely dehydrated due to the low water activity, and recovery and detection of desiccated bacteria from dry matrices and environments is critical.