Safety evaluation of certain food additives - ipcs inchem

356 ALKOXY-SUBSTITUTED ALLYLBENZENES
from 3–6 cm to 12–16 cm (Miele et al., 2001). Accordingly, early-harvested basil
contains significantly higher levels of methyl eugenol. For basil harvested at the
optimum time and stored over various periods, the concentration of methyl eugenol
in fresh leaves was 0.05%, in leaves stored 2 months, 20.4%, and in leaves crushed
and frozen at 20 °C, 1.6% (Bobin et al., 1991). These are a few of the many factors
leading to the wide variation in lower- and upper-level intakes reported in Table 1.
In certain regions, these factors are used to produce spices with more desirable
flavouring properties, containing, in some cases, relatively high levels of methoxyand
methylenedioxy-substituted allylbenzenes.
In certain regions, there are specialized consumer groups that may be
exposed to higher levels of allylbenzene derivatives. Pesto eaters ingest some of
the highest levels of methyl eugenol, because fresh pesto is prepared from a large
quantity of fresh sweet basil. Considering that a single portion of pesto may contain
up to 10 g of basil (oil content 0.5%) and that the Genovese Gigante cultivar of basil,
the most commonly used basil in pesto preparation in north-western Italy, contains
>40% methyl eugenol, a typical serving of pesto may provide up to 250 μg/kg body
weight (bw) of methyl eugenol (Miele et al., 2001). This single consumption may
result in intakes 1–2 orders of magnitude greater than mean intakes of 80 μg/day
(Table 1). However, because pesto is not consumed daily even for these specialized
consumer groups, their average lifetime intake when calculated on a daily basis
would approach mean or maximum daily intake levels for non-specialized consumer
groups.
1.2.2 Used as flavouring agents
Only estragole and methyl eugenol are used as flavouring agents, and use
is limited to the USA. Based on annual production volumes of 491 kg/year for
estragole and 77 kg/year for methyl eugenol (Gavin et al., 2007), per capita intakes
for the whole population as flavouring agents for the USA are 5 and 0.8 μg/day,
respectively.
2. BIOLOGICAL DATA
2.1 Biochemical aspects
Consistent results from pharmacokinetic and metabolic experiments for
methylenedioxy-substituted allylbenzenes—safrole (No. 1792), myristicin (No. 1791)
and apiole (No. 1787)—and methoxy-substituted allylbenzenes—methyl eugenol
(No. 1790), estragole (No. 1789) and elemicin (No. 1788)—indicate that this group
of substances undergoes rapid and essentially complete absorption following oral
intake (Kamienski & Casida, 1970; Fritsch et al., 1975a, 1975b; Benedetti et al.,
1977; Sutton et al., 1985; Anthony et al., 1987; Lee et al., 1998). Based on studies
in rats and humans, these substances are highly bioavailable following the
consumption of spices containing these constituents (Beyer et al., 2006). A number
of shared biotransformation pathways exist for this group of substances, as
described in section 2.1.2.