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Fruits, Vegetables & Grains Safety

Bacteria and other microbes in fruits and vegetables, including unpasteurized juice, and uncooked flour can cause illness.

The Drug and Poison Information Centre (DPIC) receives reports every year about foods containing toxins that cause illnesses. Some examples:

  • under-ripe potatoes that are green in colour may contain a toxin called solanine that can cause illness
  • some mushrooms can be deadly (see Death Cap Mushrooms)
  • fiddleheads can carry toxins

Flour-related outbreaks

Two different and unrelated flour outbreaks occurred in BC in 2017 causing twenty BC residents to become ill. Many people treat flour as safe but it actually a raw product. Links to public health notices describe these outbreaks.

Fruit-related outbreaks

In the past few years, several disease outbreaks have been caused by bacteria or toxins in fruits and vegetables.

In 2012, six BC residents became ill with hepatitis A virus after consuming a mixed frozen fruit blend; pomegranate seeds from Egypt were identified as the probably source.

In 2011, a large outbreak that started in Germany caused nearly 4,000 illnesses throughout Europe. People became ill after eating raw sprouts in salads and sandwiches (fenugreek sprouts). The pathogen was a novel toxin producing E. coli.

Other outbreaks were connected to spinach contaminated with E.coli in 2006, and jalapeno peppers contaminated with salmonella in 2008. A BC spinach outbreak in 2001 led to the creation of guidelines for growers about the importance of managing water and fertilizer sources.

Juice-related outbreaks

In 1996, there was an international outbreak of E.coli in unpasteurized commercial apple juice in BC and California, Colorado and Washington states. There were 45 illnesses. Many of those ill were young children who developed hemolytic uremic syndrome, affecting their kidney function. The cause of the outbreak was most likely related to apples that had been exposed to manure in the orchards. Because the apple juice was not pasteurized or heat-treated, the bacteria was able to survive in the juice.

After this outbreak codes of practice for industry and labelling requirements were put in place. This included removing manure from orchard fields, implementing a pasteurization and filtration practice to remove harmful germs and discontinuing roadside sales.

Other types of juices have caused illness too. Orange juice has been linked to salmonella illness and carrot juice has been linked to botulism. Even cranberry juice and other acidic juices may contain harmful bacteria if not properly treated or formulated.

Fruits & vegetables

As a consumer there are actions you can take with your fresh fruits and vegetables. Wash your produce to limit your exposure to harmful bacteria and other microbes. Although cooking does not destroy all toxins in foods, cooking all foods to an internal temperature of 74°C will destroy most harmful bacteria.

Juices & ciders

Freshly pressed apple juice is sometimes called apple cider in North America. Ciders normally describe fermented fruit juices. When you purchase fresh pressed juice or cider, be aware of the risks associated with unpasteurized juices.

If you are preparing your own freshly prepared apple juices or ciders, follow the recommendations in the BCCDC fact sheet How to Pasteurize Juice and Cider Safely (PDF) to help remove germs from your juices.

The How To Pasteurize Juice and Cider Safely fact sheet (PDF) explains how to pasteurize juice and cider, which is most important for people who are pregnant, immune-compromised, very young, or elderly.

Use fresh fruits that have not fallen onto the ground, and wash and sanitize the fruit before use. If you are making your own fermented cider you may also heat your juice before adding the yeast and starting the fermentation process.

Always read the label on freshly pressed juices that you purchase at a retailer. In Canada, if the juice is unpasteurized, this must be declared on the label.


Consuming flour before it has been cooked can make you sick because it may contain E. coli bacteria. E. coli is a common bacteria in the digestive tract of animals and humans, and some strains can be harmful and can cause disease. Illnesses linked to consumption of flour have been investigated in BC and Canada.

Flour is made of dried wheat or other grain varieties grown in open fields.

When harvested, the grains are separated from the wheat stalks (chaff) and the grains are sent from the fields to silos for storage and to flour mills for processing.

In the field, during the journey from the field to the flour mill, and in the mill, wheat may get contaminated by animal feces. Animal feces are the most likely source of E. coli contamination in wheat. Feces may be introduced into flour through, for example, improperly composted animal manure used as fertilizer on the wheat, or from fecal-contaminated irrigation water or runoff water, or from birds, insects, deer or rodents that may be present in the open wheat fields, or in barns, silos or flour mills.

E. coli present in the dried, ground flour will not multiply but can survive, even in the absence of moisture.

The milling process is not a cooking step, so the flour that you purchase at retail in a bag is a raw product that must be cooked.

Surveys of raw wheat flour found very low counts of E. coli (less than 10 E. coli bacteria in a gram of flour), indicating that while low, there is a risk for harmful E. coli to be present in raw flour.

BCCDC recommendations for safe flour-handling practices:

  • Do not eat or taste raw dough (e.g., cookie, pizza or bread) or raw batter (e.g., pancake or coating) or any other product containing raw flour
  • Do not sprinkle raw flour on already-cooked foods
  • Do not use recipes for no-bake cookies or other uncooked products made with raw flour
  • Follow instructions for properly baking raw pie crusts, pizza dough and other pre-made foods made with raw flour
  • Follow the cook, clean, separate, chill food-handling guidelines (see Food Safety):
    • Cook: cook foods containing raw flour to a safe internal temperature of 74°C (minimum). Check the internal temperature with a probe thermometer
    • Clean: wash hands, cutting boards, work surfaces, and utensils thoroughly with hot water and soap after contact with raw flour or dough products
    • Separate: keep raw flour products separated from ready-to-eat foods to prevent cross contamination and the spread of harmful bacteria that may be in the raw flour and dough
    • Chill: refrigerate or freeze products made with raw flour (e.g., pie tart shells) products after purchase or use. Do not leave raw flour products (e.g., pie tarts shells or pancake batter) made in the home at room temperature for longer than two hours. Refrigerate or freeze them if they are not going to be cooked or baked that day
    • Raw cookie dough, batter and pastry made with raw flour and raw eggs do have avoidable risks. The best way to limit the risk of foodborne illness is to cook these before eating to avoid. You can also choose pre-cooked or pasteurized ingredients.

Avoid eating raw cookie dough or no-bake cookies made with raw flour. Instead, choose baked cookies, or no-bake cookies made with oats and other pre-cooked or ready-to-eat ingredients Oats go through a steaming and toasting process, and are considered ready-to-eat and lower risk. Pre-cooked and ready-to-eat ingredients include cocoa powder, barley flakes, wheat flakes, toasted nuts (whole, ground or nut flours), puffed wheat or other cold cereal.

Also avoid eating raw cookie dough made with raw shell eggs. Shell eggs may be contaminated with salmonella. Choose pasteurized eggs instead, which have been heated to remove harmful bacteria.

Journey of wheat from farm to store infographic

SOURCE: Fruits, Vegetables & Grains Safety ( )
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