Control of Listeria monocytogenes in Caramel Apples by Use of Sticks Pretreated with Potassium Sorbate.

A multistate listeriosis outbreak associated with caramel apples from 2014 to 2015 prompted research on the survival of Listeria monocytogenes in fresh apples and caramel apples. Research indicated that stem end-inoculated caramel apples with stick insertion allowed for the survival and growth of L. monocytogenes at both refrigeration and ambient temperatures.

Growth Kinetics in Milkshakes Made from Naturally and Artificially Contaminated Ice Cream.

This study assessed the growth of in milkshakes made using the process-contaminated ice cream associated with a listeriosis outbreak in comparison to milkshakes made with artificially contaminated ice cream. For all temperatures, growth kinetics including growth rates, lag phases, maximum populations, and population increases were determined for the naturally and artificially derived contaminants at 5, 10, 15, and 25°C storage for 144 h. The artificially inoculated presented lower growth rates and shorter lag phases than the naturally contaminated populations at all temperatures except for 5°C, where the reverse was observed.

Fate of Listeria monocytogenes in Fresh Apples and Caramel Apples.

An outbreak of listeriosis in late 2014 and early 2015 associated with caramel apples led to questions about how this product became a vector for Listeria monocytogenes. This investigation aimed to determine information about the survival and growth of L. monocytogenes in both fresh apples and caramel apples, specifically examining the effects of site and level of inoculation, inoculum drying conditions, and storage temperature.