Food Poisoning Bulletin
A study published int he April issue of the Journal of Food Science looked at seed disinfection treatments of sprouts. In the last few years, there have been several major foodborne illness outbreaks linked to raw sprouts, including an E. coli outbreak linked to clover sprouts served at Jimmy John’s restaurants that sickened 29 people in 11 states. And there were seven recalls of sprouts for pathogenic bacterial contamination.
Sprouts are problematic for several reasons. First, the bacteria can be encapsulated inside the seed, making it impervious to physical disinfection such as the application of calcium hypochlorite. And the seeds are sprouted in warm, moist conditions, which are ideal for bacterial growth.
The FDA released guidelines in 1999 designed to limit this problem, including growing seeds using good agricultural practices, conditioning and storing seed under sanitary conditions, following GMPs at sprouting facilities, applying a disinfection treatment just before sprouting, and in-process testing of spent sprout irrigation water for pathogens before the product enters commerce. While sproutbreaks declined after these guidelines were released, the treatments are variable and food poisoning cases continue.
The study examined chemical disinfection with 20000 ppm calcium hypochlorite, and found that it does reduce microbial load on seeds. But there is a high variability in efficacy. Increasing treatment time did not improve the microbial load, but reduced germination rate of seeds. Other chemicals have not been adequately tested.
Food Poisoning Bulletin
Researchers at Rensselaer Polytechnic Institute (RPI) have found a way to kill Listeria and other pathogens without chemicals or antibiotics. Building on a method they developed to coat medical equipment with an agent that can kill antibiotic-resistant Staphylococcus aureus (MRSA), the researchers added lytic enzymes to nanoparticles of food-safe silica and to starch nanoparticles commonly used in food packaging.
“In this study, we have identified a new strategy for selectively killing specific types of bacteria. Stable enzyme-based coatings or sprays could be used in food supply infrastructure—from picking equipment to packaging to preparation—to kill Listeria before anyone has a chance to get sick from it,” said Ravi Kane, RPI’s P.K. Lashmet Professor of Chemical and Biological Engineering, in a statement. “What’s most exciting is that we can adapt this technology for all different kinds of harmful or deadly bacteria.”
FoodWorld 