Even though packaged frozen vegetables include cooking and safe handling instructions, many consumers choose other ways to consume them, such as adding them to smoothies, thawing them for salads, or snacking on them straight from the freezer.

New research from the University of Minnesota School of Public Health (SPH) suggests that these preparation habits may be unknowingly increasing consumers’ risk of foodborne illness because, unlike many other frozen foods, packaged frozen vegetables are not considered ready-to-eat and are intended to be cooked before consumption. By bypassing the recommended instructions, the study points out, consumers may be increasing their risk of contracting a foodborne illness.

Led by doctoral candidate Alexandra Edmundson, researchers surveyed 1,719 adults at the 2023 Minnesota State Fair Research Building. Participants were asked about how often they consumed frozen vegetables and frozen potatoes, how often they followed cooking instructions, and how they typically prepared nine types of frozen vegetables and seven types of frozen potato products. Researchers then analyzed how those preparation practices varied by food type and demographic characteristics.

The study, published in the Journal of Food Protection, found:

• Nearly one in six respondents reported eating at least one type of frozen vegetable without cooking it first.
• Frozen leafy greens were the vegetable most likely to be eaten raw. 38% of consumers reported they most often consumed leafy greens without cooking them. Carrots ranked second at nearly 18%.
• Frozen potatoes were rarely eaten raw. Only three respondents reported consuming frozen potatoes without cooking them, suggesting the behavior is largely limited to frozen vegetables.

“Many people think frozen vegetables are ready-to-eat foods, but they are intended to be cooked,” said Melanie Firestone, SPH assistant professor and the study’s lead author. “Previous FDA research found that 40% of consumers believe uncooked frozen vegetables are unlikely to contain bacteria or other germs that could make them sick. Our findings show there’s still a need to raise awareness that frozen vegetables should be cooked according to the package instructions to help reduce the risk of foodborne illness.”

Research for the study was led by doctoral candidate Edmundson. The researchers say the findings can help inform consumer education efforts and food safety risk assessments by identifying which frozen vegetable products are most likely to be eaten without cooking.