Dive Brief:
- Juices released from damaged salad green leaves can increase the risk of salmonella contamination in packaged salads, according to a recent study by researchers at the University of Leicester.
- These juices enabled salmonella to grow in water, even under refrigeration, the researchers said. That's despite the tendency for this bacteria to prefer a temperature of 37 C (98.6 F).
- Researchers also found that "salad leaf juices enhanced attachment of the pathogen to the plastic bag and that over a five-day period, which researchers noted was the typical storage time for bagged salad, even traces of the juice in salad bag fluids increased Salmonella growth in water by up to 280 fold over control cultures," Food Safety News reported.
Dive Insight:
These results are concerning for manufacturers of packaged salads, especially when brands like Dole have struggled with contamination in recent years. Dole found evidence of listeria at one of its salad plants, leading to a recall earlier this year, and several major retailers recalled spinach due to potential listeria contamination last year.
Those recalls differed in that they were related to listeria rather than salmonella, and the contamination occurred before the manufacturer packaged the greens. However, these instances demonstrate how exposed salad leaves can bring contamination and food safety concerns.
Packaged salads are surging in popularity as consumers demand both fresher and more convenient foods. Sales for value-added produce and RTE foods continue to grow as well, and packaged salads align with both segments.
Manufacturers may consider different packaging options to prevent salad leaves from becoming damaged and leaking juices in the first place. Bagged salads are common, but don't provide as much protection for salad leaves as sturdier plastic containers do.
However, plastic containers could cost more than bags and take up more room, which could increase shipping costs. With these new findings, there is more to consider to determine the best option for ensuring the safety of packaged salad offerings for consumers.