Results of a recent research survey published in the Journal of Food Protection show that about 9% of people do not cook frozen vegetables, although cooking instructions are stated on the product package. This is an example of 'unintended use' by consumers that needs to be accounted for by the processing facility when developing a food safety plan.
Many frozen foods facilities were built decades ago when there was no perceived risk due to organisms like Listeria monocytogenes. For one, people tended to cook frozen vegetables. They were not making vegetable smoothies where uncooked frozen vegetables are blended with fruits or yogurt. Secondly, when these plants were built, Listeria was not a recognized foodborne pathogen. This recognition did not occur until the 1980's. So the level of sanitary design needed for Listeria control was not incorporated when the plants were built. Couple that with these plants now having aged fifty-plus years, with the cracks and crevices that occur with time, Listeria control as a post-blanch contaminate is a chore.
Facilities generally blanch vegetables, which eliminates the low level of organisms present on the incoming product (if properly controlled), but the concern comes due to post-process contamination from environmental pathogens, especially Listeria. A facility's Food Safety Plan needs to recognize this potential environmental contaminate as a significant hazard and then implement Sanitation Preventive Controls to eliminate the risk of this hazard.
Journal of Food Protection
Volume 88, Issue 2, 3 February 2025, 100440
https://www.sciencedirect.com/science/article/pii/S0362028X24002242
Preparation Methods and Perceived Risk of Foodborne Illness Among Consumers of Prepackaged Frozen Vegetables – United States, September 2022
Abstract
Listeria monocytogenes causes listeriosis, a serious infection with a high mortality rate for persons at higher risk for listeriosis. The first Listeria outbreak linked to frozen vegetables occurred in 2016 and resulted in three deaths. Many frozen vegetables are intended to be consumed after cooking. However, data on consumer behavior are sparse. We characterized consumers’ perceptions of contamination of prepackaged frozen vegetables, and preparation methods of prepackaged frozen vegetables to help inform prevention strategies. During September 1–24, 2022, Porter Novelli Public Services conducted the FallStyles survey using the Ipsos KnowledgePanel. Data were weighted to be representative of the U.S. population. Point estimates and 95% CIs were calculated, and differences between respondents were determined using Wald chi square tests. Among 3,008 respondents reporting a preparation and consumption method for frozen vegetables, 8.7% (95% CI = 7.4–10.0%) reported ever consuming the product raw. Respondents who reported having children < 18 years old were more likely to report ever consuming frozen vegetables raw compared with respondents who did not (12.5% vs. 7.4%, p < 0.01). The most reported raw preparation method was adding them directly to a blender for smoothie or juice (5.6%; 95% CI = 4.6–6.7%). Among respondents who reported eating frozen vegetables, 59.6% (95% CI = 57.6–61.6%) reported following package instructions. A third (34.1% [95% CI = 32.2–35.9%]) of respondents agreed that frozen vegetables can be contaminated with germs (like Salmonella, E. coli, and Listeria), with a greater proportion of people with cancer disagreeing compared to those without cancer (32.5% vs 23.4%, p = 0.041). These findings show that some consumers may not be cooking frozen vegetables before eating them. Second, consumers might not be reading instructions on packaging. Both findings highlight the critical importance of preventive controls in the production of frozen vegetables prior to reaching the consumer.
