Analysis of Quinolizidine Alkaloids in lupins and lupin products

Increasing importance of lupins as local and vegetarian/vegan protein source

June 2020 (Update: March 2021). Eurofins Food & Feed Testing laboratories in Germany now offer the analysis of quinolizidine alkaloids in lupins and lupin products. The LC-MS/MS method covers all quinolizidine alkaloids named in an EFSA study for which reference standards are commercially available with a limit of quantification of 10 mg/kg for lupine seeds and a limit of quantification of 1 mg/kg for processed food containing lupins. The turn-around time for the analysis of quinolizidine alkaloids is 7 days with express analysis possible upon request.

Occurrence in plants

Quinolizidine alkaloids (QA) are toxic secondary plant metabolites occurring in lupins. In total, more than 170 QAs are known. Due to their high alkaloid content, wild lupins are referred to as bitter lupins. Various breedings with comparatively low alkaloid levels from the 1920s and 1930s are known as sweet lupins. Sweet lupins may contain a maximum of 5% bitter seeds (Regulation (EC) No 1121/2009). Economically important species are Lupinus albus (white lupin), Lupinus angustifolius (narrow-leaved lupin) and Lupinus luteus (yellow lupin) in Europe and Oceania, as well as Lupinus mutabilis in the Andes.

Approximately three quarters of lupin production originates from Oceania. European production accounts for approximately 200,000 mt. With their tolerance for infertile soils, lupins are ideal pioneering plants and do not require much fertilization. Additionally, they improve soil quality due to nitrogen fixation by associated rhizobial symbionts.

Occurrence in food and feed

Due to their high protein content lupins are an alternative to soybeans in food and feed. Lupin production has been supported by the German Federal Office for Agriculture and Food in a “lupin-network” from 2014 to 2019. As a local and vegan protein source lupins currently evolve to be a “trend food”.

Apart from their traditional usage as a snack in Mediterranean countries, lupins are now increasingly used as flour, in spreads and as a substitute for meat and milk. Even in bakery products, pasta, drinks and coffee substitutes lupins can be found. Additionally, lupins are used as feed for cattle, sheep, goats and in aquaculture.

Toxicology

Symptoms of acute quinolizidine alkaloid intoxication are similar to curare intoxication. As competitive acetylcholine inhibitor quinolizidine alkaloids interfere with neuronal signal transduction at the motor endplate. A resulting respiratory arrest can lead to death. Available data for chronic exposure is still very limited.

Sweet lupins can contain more than 100 mg/kg quinolizidine alkaloids; the content of QA in bitter lupins may be even higher. In Europe, currently no maximum levels for quinolizidine alkaloids in food are set. Only sweet lupins may be used as feed (Regulation (EU) No 68/2013). In Australia and New Zealand, a maximum level of 200 mg QA / kg applies for lupins (FSANZ Schedule 19, 2017). A maximum of 5 mg sparteine/kg is allowed in alcoholic beverages. The European Food Safety Authority (EFSA) has issued a scientific opinion on the risk of quinolizidine in food and feed in September 2019. Based on a margin of exposure (MOE) approach, the risk of acute intoxication is low if less than 0.16 mg QA / kg bw are taken up orally.

Primarily sweet lupins are used as food and feed but technical debittering of bitter lupins is also possible. The highest risk of acute intoxication results from insufficiently debittered lupins.

Analysis of quinolizidine alkaloids

Our experts from the Competence Centre for mycotoxins and toxic plant alkaloids of Eurofins Food & Feed Testing laboratories in Germany, Eurofins WEJ Contaminants GmbH, offer the analysis of the most important quinolizidine alkaloids via LC-MS/MS. The scope of the method covers all quinolizidine alkaloids named in the EFSA study for which reference standards are commercially available with a limit of quantification of 10 mg/kg for lupine seeds and a limit of quantification of 1 mg/kg for processed food containing lupins.

• lupanine
• α-isolupanine
• 13α-hydroxylupanine
• lupinine
• angustifoline
• sparteine
• multiflorine
• cytisine

Please contact us

Do you have any questions on the analysis of quinolizidine alkaloids? Do not hesitate to contact your personal account manager or send an e-mail to our expert Carina Kellner.