Can mashed potatoes cause food poisoning? (3+ risks)

In this article, we will answer the following question: “Can mashed potatoes cause food poisoning?” and discuss how mashed potatoes cause food poisoning, how to know if mashed potatoes are spoiled and how to store mashed potatoes to prevent them from spoiling.

Can mashed potatoes cause food poisoning?

Yes, mashed potatoes can cause food poisoning when they are not properly handled or stored. Episodes of food poisoning related to the ingestion of mashed potatoes have been reported in the scientific literature, especially as a result of unsafe storage of cooked mashed potatoes (1, 2, 3).

Some types of food poisoning caused by mashed potatoes are due to infections caused by pathogenic bacteria or their toxins. Staphylococcus aureus, Bacillus cereus, Salmonella typhi and coliforms are some of the examples of these pathogenic bacteria.

Many cases of intoxication after the consumption of cooked potato products by the toxin from Clostridium botulinum were reported as a consequence of poor food handling.

How can mashed potatoes cause food poisoning?

Mashed potatoes can cause food poisoning when they are left out unrefrigerated for more than 2 hours. Starchy foods, such as mashed potatoes, pasta and rice, are commonly infected by spores from the bacteria Bacillus cereus.

When the food is cooked, spores, which are very resistant to heat, can survive. These spores germinate and grow when conditions are favourable, such as the storage at room temperatures or temperatures between 40 °F and 140 °F (5 °C and 70 °C) (1, 2, 6).

The pathogenic bacteria Clostridium botulinum can develop and produce a toxin when mashed potatoes are stored under low oxygen conditions. This bacteria can also form spores, which grow under favourable conditions.

What are the symptoms related to food poisoning?

The symptoms related to food poisoning are in general gastrointestinal, such as nausea, vomiting, abdominal cramps and diarrhoea, or flu-like symptoms, such as fever (8).

Many cases of foodborne illnesses and poisoning have led to hospitalisations and even to death, due to infections caused by Escherichia coli, Bacillus cereus, Salmonella and Clostridium botulinum (1, 2, 3).

Poisoning by the toxin from Clostridium botulinum can cause blurry vision, dizziness and fatigue.

How to know if mashed potatoes are spoiled? 

To know if mashed potatoes are spoiled, you should be aware of the possible indications of spoilage in mashed potatoes, especially regarding the odour. Some possible signs of spoilage are (4, 5, 6):

  • Discolouration, such as darkening related to Maillard reactions, or due to the growth of moulds
  • Generation of off-odours and off-flavours related to the oxidation of lipids, such as rancidity, or other off-odours and off-flavours characterising sourness and fermentation 
  • Formation of slime on the surface or gas, leading to bloating of the container
  • Changes in the texture, dryness or formation of a ropy texture

Other FAQs about Potatoes which you may be interested in.

Do oxidized potatoes taste different?

Are potatoes fruit?

Are potatoes a root?

How to cook and store mashed potatoes?

To safely cook and store mashed potatoes to prevent food poisoning, it is necessary to follow good cooking practices, which include good personal hygienic practices, such as proper hand washing, good cleaning of the surfaces of the cooking place and the cutting boards and utensils (6, 7).

Wash the potatoes before cooking, peel them and make the mashed potatoes, according to your favourite recipe, using fresh ingredients, such as fresh milk and fresh butter.

If the mashed potatoes will not be consumed immediately or within 2 hours after being cooked, cool them down to a temperature of 70 °F (21 °C) place them in an airtight clean food container and store it in the refrigerator.

Consume the mashed potatoes within 3 to 4 days when stored in the refrigerator or place it in the freezer and consume them within 3 to 4 months. To defrost frozen mashed potatoes, place them in the fridge overnight

To reheat the leftovers, use the microwave or oven and reheat to a temperature of 165 °F (75 °C). Do not consume mashed potatoes when there are signs of spoilage.

Conclusion

In this article, we answered the following question: “Can mashed potatoes cause food poisoning?” and discussed how mashed potatoes cause food poisoning, how to know if potatoes are spoiled and how to prepare and store mashed potatoes to prevent them from spoiling.

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References

1.-

Bryan FL, Teufel P, Riaz S, Roohi S, Qadar F. Hazards and critical control points of street-vended chat, a regionally popular food in Pakistan. Journal of food protection. 1992 Sep 1;55(9):708-13.

2.-

Harmon SM, Kautter DA. Incidence and growth potential of Bacillus cereus in ready-to-serve foods. Journal of Food Protection. 1991 May 1;54(5):372-4.

3.-

Doan CH, Davidson PM. Microbiology of potatoes and potato products: a review. Journal of food protection. 2000 May 1;63(5):668-83.

4.-

Zhang H, Tang Z, Rasco B, Tang J, Sablani SS. Shelf-life modeling of microwave-assisted thermal sterilized mashed potato in polymeric pouches of different gas barrier properties. Journal of Food Engineering. 2016 Aug 1;183:65-73.

5.-

Rawat S. Food Spoilage: Microorganisms and their prevention. Asian journal of plant science and Research. 2015;5(4):47-56.

6.-

Coorey R, Ng DS, Jayamanne VS, Buys EM, Munyard S, Mousley CJ, Njage PM, Dykes GA. The impact of cooling rate on the safety of food products as affected by food containers. Comprehensive Reviews in Food Science and Food Safety. 2018 Jul;17(4):827-40.

7.-

Usda.gov. [cited 2023 Aug 11]. Available from: https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/leftovers-and-food-safety

8.-

Usda.gov. [cited 2023 Aug 24]. Available from: https://www.fsis.usda.gov/food-safety/foodborne-illness-and-disease