Scientific Opinion on Flavouring Group Evaluation 217 Revision 2 (FGE.217Rev2), consideration of genotoxic potential for α,β-unsaturated ketones and precursors from chemical subgroup 4.1 of FGE.19: lactones

Occurrence and Synthesis Pathways of (Suspected) Genotoxic α,β-Unsaturated Carbonyls in Chocolate and Other Commercial Sweet Snacks

α,β-Unsaturated carbonyls are highly reactive and described as structural alerts for genotoxicity. Ten of them (either commercially available or synthesized here by combinatorial chemistry) were first investigated throughout the chocolate-making process by solvent-assisted flavor evaporation (SAFE) coupled to GC-MS/SIM. Monitored α,β-unsaturated aldehydes were formed during chocolate production, primarily through aldol condensation of Strecker aldehydes triggered by bean roasting. Notably, levels of 2-phenylbut-2-enal (up to 399 μg·kg-1) and 5-methyl-2-phenylhex-2-enal (up to 216 μg·kg-1) increased up to 40-fold. Dry conching caused evaporation of α,β-unsaturated carbonyls, while wet conching partially restored or increased their levels due to cocoa butter addition. Further analyses showed that α,β-unsaturated aldehydes also occurred in most commercial sweet snacks (up to 16 μg·kg-1), although often at lower concentrations than in roasted cocoa or derived chocolates. In the end, none of the monitored α,β-unsaturated aldehydes did raise a health concern compared to current maximum use levels (2-5 mg·kg-1). On the other hand, much higher levels of genotoxic furan-2(5H)-one were found in crepe and cake samples (up to 4.3 mg·kg-1).

Mechanisms of Nitrosamine Mutagenicity and Their Relationship to Rodent Carcinogenic Potency

A thorough literature review was undertaken to understand how the pathways of N-nitrosamine transformation relate to mutagenic potential and carcinogenic potency in rodents. Empirical and computational evidence indicates that a common radical intermediate is created by CYP-mediated hydrogen abstraction at the α-carbon; it is responsible for both activation, leading to the formation of DNA-reactive diazonium species, and deactivation by denitrosation. There are competing sites of CYP metabolism (e.g., β-carbon), and other reactive species can form following initial bioactivation, although these alternative pathways tend to decrease rather than enhance carcinogenic potency. The activation pathway, oxidative dealkylation, is a common reaction in drug metabolism and evidence indicates that the carbonyl byproduct, e.g., formaldehyde, does not contribute to the toxic properties of N-nitrosamines. Nitric oxide (NO), a side product of denitrosation, can similarly be discounted as an enhancer of N-nitrosamine toxicity based on carcinogenicity data for substances that act as NO-donors. However, not all N-nitrosamines are potent rodent carcinogens. In a significant number of cases, there is a potency overlap with non-N-nitrosamine carcinogens that are not in the Cohort of Concern (CoC; high-potency rodent carcinogens comprising aflatoxin-like-, N-nitroso-, and alkyl-azoxy compounds), while other N-nitrosamines are devoid of carcinogenic potential. In this context, mutagenicity is a useful surrogate for carcinogenicity, as proposed in the ICH M7 (R2) (2023) guidance. Thus, in the safety assessment and control of N-nitrosamines in medicines, it is important to understand those complementary attributes of mechanisms of mutagenicity and structure-activity relationships that translate to elevated potency versus those which are associated with a reduction in, or absence of, carcinogenic potency.

Occurrence of Perillaldehyde and Other (Suspected) Genotoxic Flavoring Substances in Water-Based Beverages Consumed by Belgian Children

Despite the extensive use of flavoring substances in food, their monitoring for regulatory purposes is currently limited. This raises public health issues, especially as some compounds are prohibited due to (geno)toxicity. A solvent-assisted flavor evaporation (SAFE) method coupled with GC/MS (SIM) was validated here for diverse water-based beverages. Thirty flavoring substances out of the 38 targeted were validated, showing good analytical performances and confirming the versatility of the SAFE technique. The method was then applied to 94 samples, including fruit juices, iced teas, lemonades, colas, and sports beverages. Overall, seven different flavoring substances of interest were detected in the samples. Perillaldehyde and furan-2(5H)-one, two genotoxic flavoring substances, were found at concentrations up to 153 and 143 μg·kg-1, respectively. Perillaldehyde levels were significantly higher in commercial citrus juices than in freshly squeezed juices. Food control laboratories could use the developed method to face the current growing need to improve flavoring substance monitoring and conduct risk assessments.

Scientific opinion on the renewal of the authorisation of proFagus Smoke R714 (SF-001) as a smoke flavouring Primary Product

The EFSA Panel on Food Additives and Flavourings (FAF) was requested to evaluate the safety of the smoke flavouring Primary Product proFagus Smoke R714 (SF-001), for which a renewal application was submitted in accordance with Article 12(1) of Regulation (EC) No 2065/2003. This opinion refers to the assessment of data submitted on chemical characterisation, dietary exposure and genotoxicity of the Primary Product. ProFagus Smoke R714 is obtained by pyrolysis of beech and oak woods as main source materials. Based on the compositional data, the Panel noted that the identified and quantified proportion of the solvent-free fraction amounts to 39 weight (wt)%, thus the applied method does not meet the legal quality criterion that at least 50% of the solvent-free fraction shall be identified and quantified. At the maximum proposed use levels, dietary exposure estimates calculated with DietEx ranged from 0.7 to 10.9 mg/kg body weight (bw) per day at the mean and from 2.2 to 42.5 mg/kg bw per day at the 95th percentile. The Panel concluded that three components in the Primary Product raise a potential concern for genotoxicity. In addition, a potential concern for genotoxicity was identified for the unidentified part of the mixture. The Primary Product contains furan-2(5H)-one, for which a concern for genotoxicity was identified in vivo upon oral administration. Considering that the exposure estimates for this component are above the threshold of toxicological concern (TTC) of 0.0025 μg/kg bw per day for DNA-reactive mutagens and/or carcinogens, the Panel concluded that the Primary Product raises concern with respect to genotoxicity.

Flavouring Group Evaluation 217 Revision 3 (FGE.217Rev3): consideration of genotoxic potential for α,β-unsaturated ketones and precursors from chemical subgroup 4.1 of FGE.19: lactones

The Panel on Food Additives and Flavourings of the European Food Safety Authority was requested to evaluate the genotoxic potential of four flavouring substances [FL-no: 10.023, 10.030, 10.057 and 13.012] from subgroup 4.1 of FGE.19. For three of these substances [FL-no: 10.023, 10.030 and 13.012], the concern for genotoxicity has been ruled out in previous revisions of Flavouring Group Evaluation 217 (FGE.217). However, in FGE.217Rev2, a concern for genotoxicity could not be ruled out for 3a,4,5,7a-tetrahydro-3,6-dimethylbenzofuran-2(3H)-one [FL-no: 10.057]. After publication of FGE.217Rev2, industry provided additional genotoxicity studies for [FL-no: 10.057], which are evaluated in the present opinion FGE.217Rev3. The flavouring substance [FL-no: 10.057] did not induce gene mutations or numerical or structural chromosomal aberrations in vitro. Based on these data, the Panel concluded that the concern for genotoxicity is ruled out for [FL-no: 10.057]. Consequently, it can be evaluated through the Procedure.

Scientific opinion on Prosmoke BW 01

The EFSA Panel on Food Additives and Flavourings (FAF) was requested to evaluate the safety of Prosmoke BW 01 as a new smoke flavouring primary product, in accordance with Regulation (EC) No 2065/2003. Prosmoke BW01 is produced by pyrolysis of beechwood (Fagus sylvatica L.) sawdust. Its water content is estimated at 56 wt%, the total identified volatile fraction accounts for 28 wt% of the primary product, corresponding to 64% of the solvent-free mass, while the unidentified fraction amounts to 16 wt% of the primary product. Analytical data provided for three batches demonstrated that their batch-to-batch-variability was sufficiently low. However, for the batch used for the toxicological studies, there were substantial deviations in the concentration of nearly all the constituents compared to the other three batches. The dietary exposure of Prosmoke BW 01 was estimated to be between 6.2 and 9.2 mg/kg body weight (bw) per day, respectively, using SMK-EPIC and SMK-TAMDI. Using the FAIM tool, the 95th percentile exposure estimates ranged from 3.2 mg/kg bw per day for the elderly to 17.9 mg/kg bw per day for children. The Panel noted that furan-2(5H)-one is present in all batches of the primary product at an average concentration of 0.88 wt%. This substance was evaluated by the FAF Panel as genotoxic in vivo after oral exposure. The Panel considered that the (geno)toxicity studies available on the whole mixture were not adequate to support the safety assessment, due to limitations in these studies and because they were performed with a batch which may not be representative for the material of commerce. Considering that the exposure estimates for furan-2(5H)-one are above the TTC value of 0.0025 μg/kg bw per day (or 0.15 μg/person per day) for DNA-reactive mutagens and/or carcinogens, the Panel concluded that Prosmoke BW 01 raises a concern with respect to genotoxicity.