Glycoalkaloids in potatoes and potato products
EU publishes monitoring recommendation for glycoalkaloids
Sep 2022. This year, the EU Commission has published a recommendation to monitor the levels of glycoalkaloids in potatoes and processed potato products. This recommendation is based on EFSA's risk assessment of 2020. Learn here the key contents of the EU Commission's recommendation, the risk assessment and some tips to reduce glycoalkaloids in your products.
New guideline value for glycoalkaloids in potatoes and processed potato products
The EU sets an indicative level of 100 mg/kg as the sum of α-solanine and α-chaconine in potatoes and processed potato products in its Commission Recommendation (EU) 2022/561[1] of 6 April 2022 on monitoring the presence of glycoalkaloids in potatoes and potato-derived products. If this guideline value is exceeded, the causes are to be determined.
In addition to the glycoalkaloids α-solanine and α-chaconine, it is also useful to examine for degradation products and aglycone, especially in processed potato products. The following substances are mentioned in the recommendation:
- α-solanine
- α-chaconine
- β- and γ-solanine
- β- and γ-chaconine
- solanidine
Monitoring of glycoalkaloids and data submission to EFSA
According to the recommendation of the EU Commission, member states and food business operators are to monitor the levels of glycoalkaloids. In addition, the member states and food business operators are requested to submit the determined data of the previous year to EFSA by 30 June of each year. This includes information on
- variety and the size of potatoes
- early potatoes or storage potatoes
- place of sampling (producer, wholesale, retail)
- processing (e.g. peeled or unpeeled)
Subsequently, measures should be worked out to prevent or reduce the occurrence of glycoalkaloids. Further information on submission requirements can be found on EFSA's website[2] and in EFSA's guidance on Standard Sample Description (SSD)[3] for food and feed.
Interesting facts about glycoalkaloids in food and feed from EFSA's risk assessment
Glycoalkaloids are natural plant constituents found in many plants of the family of Solanaceae. They contribute to plant resistance against pests and pathogens. In addition to potatoes, Solanaceae also includes tomatoes and eggplants, for example. Potatoes mainly contain α-solanine and α-chaconine. These two substances are compounds of the aglycone solanidin with an oligosaccharide side chain (chacotriose and solatriose, respectively).
Toxic effects of potato glycoalkaloids
As an acute toxic effect, gastrointestinal symptoms such as vomiting, diarrhea, and abdominal pain may occur in humans after ingestion of potato glycoalkaloids. In severe cases, paralysis, respiratory failure, cardiac failure, coma and death may occurr. Total doses in the range of 3-6 mg total potato glycoalkaloids/kg body weight are potentially lethal to humans. With regard to acute toxic effects, EFSA has derived a LOAEL (Lowest Observed Adverse Effect Level) of 1 mg total potato glycoalkaloids/kg body weight per day. This is the lowest dose at which an adverse effect still occurs.
To date, no genotoxicity has been demonstrated for α-solanine, α-chaconine and the aglycone solanidine. However, the number of available studies is limited, so that the genotoxic potential cannot be conclusively assessed. This also applies to the effects of repeated or long-term ingestion. In addition, no study on long-term chronic toxicity and carcinogenicity is yet known.
Exposure of humans with potato glycoalkaloids
EFSA determined an average level of 51.2 mg/kg in potatoes for the sum of α-solanine and α-chaconine, and a level of 116.8 mg/kg for the 95th percentile. A maximum content of 276.6 mg/kg was determined. Considering the estimated acute dietary exposure, health concerns arise for infants and young children. For the adult age groups, only large consumption levels result in health concerns.
Risk assessment of other glycoalkaloids
The risk to human health from glycoalkaloids present in tomatoes and eggplants could not be assessed because there were no data on the occurrence of these glycoalkaloids and only limited data on toxicity.
Reducing glycoalkaloids in potatoes
The processing of potatoes can already lead to a reduction of the glycoalkaloid content. For example, peeling, boiling and frying can reduce the content by 5 to 90%. In addition, the German Federal Institute for Risk Assessment (BfR) has already made the following recommendations for the storage and preparation of potatoes[4] in 2018:
- Cool, dark and dry storage
- No consumption of old, dried or germinating potatoes, green spots, "eyes" or bitter potato dishes
- Eat the skin only if the potatoes are fresh and unharmed
- Small children should eat potatoes only peeled
- Do not reuse potato cooking water and regularly change the frying fat for potato products
Analysis of glycoalkaloids
The EU recommends the analysis of glycoalkaloids by liquid chromatography with UV diode array detection (LC-UV-DAD) or with mass spectrometry coupling (LC-MS). The limit of quantification (LOQ) of each substance should be around 1 mg/kg.
Our accredited method uses LC-MS/MS for measurement and has a LOQ of 1 mg/kg. With this method, the two glycoalkaloids α-solanine and α-chaconine can be determined in plants of the family of Solanaceae and products made from them.
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Relevant Sources
[1] Commission Recommendation (EU) 2022/561 on monitoring the presence of glycoalkaloids in potatoes and potato-derived productsg
[2] EFSA: Call for continuous collection of chemical contaminants occurrence data in food and feed
[3] EFSA: Standard Sample Description 2.0 (SSD)
[4] FAQ to the BfR from 23 April 2018: Frequently asked questions about solanine (glycoalkaloids) in potatoes
Written by:
Stephanie Frisch
Eurofins Food & Feed Testing Leipzig GmbH