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PA research II: PAs in dry tea
product and their migration into
tea infusions
The BfR is a partner in an EFSA project
aimed at investigating food products
in Europe for potential PA content. The
job of the BfR is to analyse herbal
teas, teas and food supplements. In
addition, the institute is looking into
the migration of PAs from tea leaves
into tea beverages. For this purpose,
PA profiles and concentrations are
measured in the dry tea product and
the tea infusion and compared with
one another. Moreover, consumer
habits with regard to tea preparation
are being simulated and the influence
of these habits on migration of PAs
into the beverage investigated. These
findings make a key contribution to
assessing the risk of PAs in herbal tea
and tea.
Analytical determination of pyrrolizidine alkaloids in
herbal tea and tea samples
To better assess the potential health risks, the BfR carried out a research
project to measure the concentrations of unsaturated pyrrolizidine
alkaloids in food and feed – including herbal teas and teas. The tested
tea varieties were baby fennel tea, fennel tea, chamomile tea, herbal
tea, peppermint tea, nettle tea, melissa tea, rooibos tea, black tea and
green tea. A total of 184 herbal tea and tea samples from retail out-
lets and 37 medicinal teas from pharmacies were analysed by means
of solid phase extraction followed by liquid chromatography tandem
mass spectrometry. The determination of total PA concentration in the
herbal tea and tea samples was based on the concentrations of seven-
teen individually measured PAs. The first results measured in the non-representative tests were total PA concentrations from 0 to 3.4 milligrams
PA per kilogram of dry product in the tested herbal tea and tea samples.
Potential health risks for high consumers, children,
pregnant women and breastfeeding women
The total PA concentrations in herbal tea and tea samples from the re-
search project subsequently were evaluated in a risk assessment by
the BfR. Estimation of exposure was based on the measured concen-
tration data and the consumption data for herbal tea and tea for adults
from the NVS II National Food Consumption Study and for children from
the VELS study (food consumption survey to determine food intake by
infants and small children for the estimation of the acute toxicity risk
from pesticide residues). The BfR used the MOE (Margin of Exposure)
method, which is an internationally recognised approach to estimate the
potential health risks of substances with genotoxic and carcinogenic
effects. The MOE is calculated from the ratio of two factors: human ex-
posure as a measure of the extent of oral intake of a substance and the
effective oral dose established or calculated in animal tests for a given
tumour incidence. It is assumed here that a MOE of 10,000 or higher for
genotoxic carcinogens poses little danger to health.
In its risk assessment, the BfR came to the conclusion that, despite
the fact that unexpectedly high PA concentrations were measured in
the samples, it is unlikely that short-term intake poses an acute health
risk to adults and children. A short-term intake is considered to be an
intake lasting up to 14 days. With longer-term intake, an impairment to
health is also unlikely in average consumers (adults and children) who
do not prefer any specific variety of herbal tea. Here, the MOE values
are above the relevant health-related margin of 10,000.
Among other things, the BfR measures
the concentrations of pyrrolizidine alka-
loids that migrate into the beverage when
people make tea infusions.
Main Topics 2013 | Pyrrolizidine alkaloids in teas
