The European Food Safety Authority (EFSA) has advised peeling, boiling, and frying to reduce a compound in potatoes that can cause poisoning.

Glycoalkaloids are naturally occurring compounds found in plants including potatoes, tomatoes, and eggplant (aubergines), and contribute to resistance against pests and pathogens. Glycoalkaloid poisoning can cause acute gastrointestinal symptoms, such as nausea, vomiting, and diarrhea.

In severe cases, paralysis, respiratory insufficiency, cardiac failure, coma, and death have been reported. Doses in the range of 3 to 6 milligrams per kilogram of body weight are considered to be potentially lethal.

Experts identified a health concern for infants and toddlers, considering both mean and high consumers. Among adults, there was only an issue for high consumers.

Reduction measures
EFSA set the lowest observed adverse effect level of 1 milligram per kilogram of body weight per day based on human data from case reports, outbreaks, and studies in volunteers. This is the lowest dose at which undesired effects are observed. No evidence of health problems associated with repeated or long‐term intake has been identified.

For tomato and eggplant glycoalkaloids, the risk to human health could not be characterized due to the lack of occurrence data and limited toxicity data.

Processing of potatoes has been reported to reduce glycoalkaloids in the final product. Peeling reduced the content by 25 to 75 percent, boiling in water and blanching of peeled potatoes by 5 to 65 percent and frying in oil of peeled potatoes by 20 to 90 percent. Microwave and oven baking of unpeeled potatoes may cause a reduction by 3 to 45 percent and 20 to 50 percent, respectively.

Factors such as the duration of storage, temperature, light exposure, as well as tuber damage can affect the glycoalkaloid content during the storage of potato tubers. High concentrations can be found in the sprouts and stem buds or “eyes”. Green parts indicate elevated glycoalkaloid content.

In 2018, and after the intoxication of a family in Baden–Württemberg from potatoes in 2015, the German Federal Institute for Risk Assessment (BfR) published an assessment on the acute toxicity of potato glycoalkaloids.

Analytical results showed the potatoes contained 236 milligrams of glycoalkaloids per kilogram. BfR recommended the content of potatoes should not be higher than 100 milligrams per kilogram (mg/kg) of potatoes.

National rules
Hungary has rules of 100 mg/kg as the maximum limit of solanine equivalents of raw, unpeeled potatoes. In Finland, a max level for glycoalkaloids in potatoes of 200 mg/kg exists. Denmark has a guideline of 200 mg GAs/kg for known potatoes varieties and 100 mg/kg for new potatoes types. The maximum acceptable content of potato tubers of 20 to 25 mg per 100-gram of fresh potato (equivalent to 200–250 mg/kg) has been set in the United States.

The mean UB occurrence for main‐crop and new potatoes was 51.2 mg/kg and the P95 occurrence was 116.8 mg/kg. The minimum and maximum concentrations were 1.1 mg/kg and 276.6 mg/kg, respectively, according to the risk assessment.

Experts calculated the mean percentage of days with potato consumption across surveys per age group on which the potato glycoalkaloids intake may be below the MOE of 10. A MOE higher than 10 indicates that there is no health concern.

The highest number of survey days was estimated for toddlers followed by children. For other age groups, the estimated intake was below the MOE of 10 in up to 22 to 40 percent of the survey days.

A public consultation received nine comments from national authorities such as the Norwegian Scientific Committee for Food and Environment, Panel on Contaminants and National Institute for Public Health and the Environment (RIVM) in the Netherlands and industry groups European Potato Processors’ Association and Starch Europe.

Experts recommended measures to improve the risk assessment and reduce uncertainties such as occurrence data on glycoalkaloids and their aglycones in potato processed products, including foods for infants and in tomato and eggplant products.

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