A recall of frozen fruit products distributed by major retailers was recently initiated due to contamination of pineapple with Listeria monocytogenes. Little information is provided on where the contamination was detected or how it occurred. Pineapple generally has a low pH below 4.0 that would inhibit Listeria outgrowth. However, pineapple has been involved in outbreaks and pathogens can persist in low pH products and cause illness. The following provides a review of past pineapple incidents and findings.
Pineapple is commonly started in fields by vegetative propagation (i.e. using cuttings from mother plants) producing fruit in 15-22 months. Greater than an inch of water is required each week for growth. The pineapple fruits are harvested by hand and transported to a factory where they are washed, peeled, and cut into pieces prior to final processing into fresh, frozen, or canned products.
While pineapple has not been implicated in outbreaks of L. monocytogenes, it has been associated with outbreaks resulting from enterohemorrhagic E. coli O11:H43 in 1994, Salmonella Weltevreden in 1996, and Salmonella Javiana in 2020. The 1996 outbreak resulted from contaminated industrial water used to wash the fresh produce. A warning letter issued in response to the 2020 outbreak investigation found the following violations:
- The hazard analysis did not identify and evaluate environmental pathogens to determine whether they are a hazard requiring a preventive control (e.g., sanitation controls).
- Lapses in GMPs and Sanitation
- Cleaning did not occur prior to sanitizing. o Monitoring, verification, and record keeping were not implemented.
- Handwashing SOPs were not implemented correctly
- Environmental monitoring procedures to verify sanitation controls were not written or implemented.
- Supply-chain controls were not implemented
- Reasonably foreseeable hazards such as Salmonella, L. monocytogenes, and pathogenic E. coli were not assessed for the raw agricultural commodities.
- The washing step was not an adequate preventive control for pathogens if controls are not also in place by the supplier to minimize pathogen contamination.
Listeria monocytogenes is ubiquitous in nature and a natural part of the pineapple growing environment that can transfer to downstream products through environmental contamination during further processing. Once the fruit is manipulated by peeling, cutting, etc. it falls under the Preventive Controls for Human Food Rule and FDA considers L. monocytogenes a pathogen hazard that requires control.
If there is a lapse in control, pathogens such as E. coli O157:H7, Salmonella, and L. monocytogenes have shown the ability to persist in low pH products stored at freezing temperature for long periods of time, potentially resulting in illness if consumed