Re-evaluation of propane-1,2-diol (E 1520) as a food additive

Pitfalls in the Detection of Volatiles Associated with Heated Tobacco and e-Vapor Products When Using PTR-TOF-MS

We investigated the applicability of proton transfer reaction-time-of-flight mass spectrometry (PTR-TOF-MS) for quantitative analysis of mixtures comprising glycerin, acetol, glycidol, acetaldehyde, acetone, and propylene glycol. While PTR-TOF-MS offers real-time simultaneous determination, the method selectivity is limited when analyzing compounds with identical elemental compositions or when labile compounds present in the mixture produce fragments that generate overlapping ions with other matrix components. In this study, we observed significant fragmentation of glycerin, acetol, glycidol, and propylene glycol during protonation via hydronium ions (H3O+). Nevertheless, specific ions generated by glycerin (m/z 93.055) and propylene glycol (m/z 77.060) enabled their selective detection. To thoroughly investigate the selectivity of the method, various mixtures containing both isotope-labeled and unlabeled compounds were utilized. The experimental findings demonstrated that when samples contained high levels of glycerin, it was not feasible to perform time-resolved analysis in H3O+ mode for acetaldehyde, acetol, and glycidol. To overcome the observed selectivity limitations associated with the H3O+ reagent ions, alternative ionization modes were investigated. The ammonium ion mode proved appropriate for analyzing propylene glycol (m/z 94.086) and acetone (m/z 76.076) mixtures. Concerning the nitric oxide mode, specific m/z were identified for acetaldehyde (m/z 43.018), acetone (m/z 88.039), glycidol (m/z 73.028), and propylene glycol (m/z 75.044). It was concluded that considering the presence of multiple product ions and the potential influence of other compounds, it is crucial to conduct a thorough selectivity assessment when employing PTR-TOF-MS as the sole method for analyzing compounds in complex matrices of unknown composition.

Latest Insights on Novel Deep Eutectic Solvents (DES) for Sustainable Extraction of Phenolic Compounds from Natural Sources

Phenolic compounds have long been of great importance in the pharmaceutical, food, and cosmetic industries. Unfortunately, conventional extraction procedures have a high cost and are time consuming, and the solvents used can represent a safety risk for operators, consumers, and the environment. Deep eutectic solvents (DESs) are green alternatives for extraction processes, given their low or non-toxicity, biodegradability, and reusability. This review discusses the latest research (in the last two years) employing DESs for phenolic extraction, solvent components, extraction yields, extraction method characteristics, and reviewing the phenolic sources (natural products, by-products, wastes, etc.). This work also analyzes and discusses the most relevant DES-based studies for phenolic extraction from natural sources, their extraction strategies using DESs, their molecular mechanisms, and potential applications.

The Additive Influence of Propane-1,2-Diol on SDS Micellar Structure and Properties

Micellar systems are colloids with significant properties for pharmaceutical and food applications. They can be used to formulate thermodynamically stable mixtures to solubilize hydrophobic food-related substances. Furthermore, micellar formation is a complex process in which a variety of intermolecular interactions determine the course of formation and most important are the hydrophobic and hydrophilic interactions between surfactant-solvent and solvent-solvent. Glycols are organic compounds that belong to the group of alcohols. Among them, propane-1,2-diol (PG) is a substance commonly used as a food additive or ingredient in many cosmetic and hygiene products. The nature of the additive influences the micellar structure and properties of sodium dodecyl sulfate (SDS). When increasing the mass fraction of propane-1,2-diol in binary mixtures, the c.m.c. values decrease because propane-1,2-diol is a polar solvent, which gives it the ability to form hydrogen bonds, decreasing the cohesivity of water and reducing the dielectric constant of the aqueous phase. The values of ΔGm0 are negative in all mixed solvents according to the reduction in solvophobic interactions and increase in electrostatic interaction. With the rising concentration of cosolvent, the equilibrium between cosolvent in bulk solution and in the formed micelles is on the side of micelles, leading to the formation of micelles at a lower concentration with a small change in micellar size. According to the 1H NMR, with the addition of propylene glycol, there is a slight shift of SDS peaks towards lower ppm regions in comparison to the D2O peak. The shift is more evident with the increase in the amount of added propane-1,2-diol in comparison to the NMR spectra of pure SDS. Addition of propane-1,2-diol causes the upfield shift of the protons associated with hydrophilic groups, causing the shielding effect. This signifies that the alcohol is linked with the polar head groups of SDS due to its proximity to the SDS molecules.

Chemical Characterization of Electronic Cigarette (e-cigs) Refill Liquids Prior to EU Tobacco Product Directive Adoption: Evaluation of BTEX Contamination by HS-SPME-GC-MS and Identification of Flavoring Additives by GC-MS-O

The present study focused on the determination of benzene, toluene, ethylbenzene and xylenes (BTEX) concentration levels in 97 refill liquids for e-cigs selected by the Italian National Institute of Health as representative of the EU market between 2013 and 2015 prior to the implementation of the European Union (EU) Tobacco Product Directive (TPD). Most of the e-liquids investigated (85/97) were affected by BTEX contamination, with few exceptions observed (levels below the limit of quantification (LOQ) of headspace-solid phase micro extraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) methodology). Across brands, concentration levels ranged from 2.7 to 30,200.0 µg/L for benzene, from 1.9 to 447.8 µg/L for ethylbenzene, from 1.9 to 1,648.4 µg/L for toluene and from 1.7 to 574.2 µg/L for m,p,o-xylenes. The variability observed in BTEX levels is likely to be related to the variability in contamination level of both propylene glycol and glycerol and flavoring additives included. No correlation was found with nicotine content. Moreover, on a limited number of e-liquids, gas chromatography-mass spectrometry-olfactometry (GC-MS-O) analysis was performed, allowing the identification of key flavoring additives responsible of specific flavor notes. Among them, diacetyl is a flavoring additive of concern for potential toxicity when directly inhaled into human airways. The data reported are eligible to be included in the pre-TPD database and may represent a reference for the ongoing evaluation on e-liquids safety and quality under the current EU Legislation.

Value and limitation of structure-based profilers to characterize developmental and reproductive toxicity potential

The uncertainty regarding the safety of chemicals leaching from food packaging triggers attention. In silico models provide solutions for screening of these chemicals, since many are toxicologically uncharacterized. For hazard assessment, information on developmental and reproductive toxicity (DART) is needed. The possibility to apply in silico toxicology to identify and quantify DART alerts was investigated. Open-source models and profilers were applied to 195 packaging chemicals and analogues. An approach based on DART and estrogen receptor (ER) binding profilers and molecular docking was able to identify all except for one chemical with documented DART properties. Twenty percent of the chemicals in the database known to be negative in experimental studies were classified as positive. The scheme was then applied to 121 untested chemicals. Alerts were identified for sixteen of them, five being packaging substances, the others structural analogues. Read-across was then developed to translate alerts into quantitative toxicological values. They can be used to calculate margins of exposure (MoE), the size of which reflects safety concern. The application of this approach appears valuable for hazard characterization of toxicologically untested packaging migrants. It is an alternative to the use of default uncertainty factor (UF) applied to animal chronic toxicity value to handle absence of DART data in hazard characterization.

Evaluation of Second-Hand Exposure to Electronic Cigarette Vaping under a Real Scenario: Measurements of Ultrafine Particle Number Concentration and Size Distribution and Comparison with Traditional Tobacco Smoke

The present study aims to evaluate the impact of e-cig second-hand aerosol on indoor air quality in terms of ultrafine particles (UFPs) and potential inhalation exposure levels of passive bystanders. E-cig second-hand aerosol characteristics in terms of UFPs number concentration and size distribution exhaled by two volunteers vaping 15 different e-liquids inside a 49 m3 room and comparison with tobacco smoke are discussed. High temporal resolution measurements were performed under natural ventilation conditions to simulate a realistic exposure scenario. Results showed a systematic increase in UFPs number concentration (part cm-3) related to a 20-min vaping session (from 6.56 × 103 to 4.01 × 104 part cm-3), although this was one up to two order of magnitude lower than that produced by one tobacco cigarette consumption (from 1.12 × 105 to 1.46 × 105 part cm-3). E-cig second-hand aerosol size distribution exhibits a bimodal behavior with modes at 10.8 and 29.4 nm in contrast with the unimodal typical size distribution of tobacco smoke with peak mode at 100 nm. In the size range 6-26 nm, particles concentration in e-cig second-hand aerosol were from 2- (Dp = 25.5 nm) to 3800-fold (Dp = 9.31 nm) higher than in tobacco smoke highlighting that particles exhaled by users and potentially inhaled by bystanders are nano-sized with high penetration capacity into human airways.

Re-evaluation of propane-1,2-diol esters of fatty acids (E 477) as a food additive

The EFSA Panel on Food Additives and Flavourings (FAF) provides a scientific opinion re-evaluating the safety of propane-1,2-diol esters of fatty acids (E 477) when used as a food additive. The Scientific Committee on Food (SCF) in 1978 endorsed the acceptable daily intake (ADI) of 25 mg/kg body weight (bw) per day, expressed as propane-1,2-diol, established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) in 1974. No adverse effects were observed in short-term studies in rats and dogs at the highest doses tested. The Panel considered that E 477 did not raise a concern for genotoxicity. No chronic toxicity, carcinogenicity, reproductive and developmental toxicity studies with propane-1,2-diol esters of fatty acids were available to the Panel. The Panel considered that any potential adverse effect of propane-1,2-diol ester of fatty acids would be due to propane-1,2-diol, previously re-evaluated as a food additive and for which an ADI of 25 mg/kg bw per day was established. Considering the overall metabolic and toxicity database, the Panel confirmed the previously established ADI for propane-1,2-diol esters of fatty acids (E 477) of 25 mg/kg bw per day expressed as propane 1,2 diol. This corresponds to an ADI for E 477 of 80 mg/kg bw per day, based on the concentration of free and bound propane-1,2-diol amounting to a maximum of 31% as laid down in the EU specification. The Panel concluded that there would not be a safety concern at the reported use levels for E 477 because exposure estimates from the refined non-brand loyal scenario did not exceed the ADI for E 477 in any of the population groups. However, the Panel aims to explore the feasibility of establishing a group ADI for those food additives that result in an exposure to propane-1,2-diol, such as E 477, E 1520 and E 405. Additionally, the Panel will also consider performing a combined exposure assessment to propane-1,2-diol resulting from the use of these food additives. The Panel also recommended some modifications of the EU specifications for E 477.

Re-evaluation of propane-1,2-diol alginate (E 405) as a food additive

The present opinion deals with the re‐evaluation of propane‐1,2‐diol alginate (E 405) when used as a food additive. The Panel noted that absorption, distribution, metabolism and excretion (ADME) data on propane‐1,2‐diol alginate gave evidence for the hydrolysis of this additive into propane‐1,2‐diol and alginic acid. These two compounds have been recently re‐evaluated for their safety of use as food additives (EFSA ANS Panel, 2017, 2018). Consequently, the Panel considered in this opinion the major toxicokinetic and toxicological data of these two hydrolytic derivatives. No adverse effects were reported in subacute and subchronic dietary studies with propane‐1,2‐diol alginate. The available data did not indicate a genotoxic concern for propane‐1,2‐diol alginate (E 405) when used as a food additive. Propane‐1,2‐diol alginate, alginic acid and propane‐1,2‐diol were not of concern with respect to carcinogenicity. The Panel considered that any adverse effect of propane‐1,2‐diol alginate would be due to propane‐1,2‐diol. Therefore, the acceptable daily intake (ADI) of the food additive E 405 is determined by the amount of free propane‐1,2‐diol and the propane‐1,2‐diol released from the food additive after hydrolysis. According to the EU specification, the concentration of free and bound propane‐1,2‐diol amounts to a maximum of 45% on a weight basis. On the worst‐case assumption that 100% of propane‐1,2‐diol would be systemically available and considering the ADI for propane‐1,2‐diol of 25 mg/kg body weight (bw) per day, the Panel allocated an ADI of 55 mg/kg bw per day for propane‐1,2‐diol alginate. The Panel concluded that exposure estimates did not exceed the ADI in any of the population groups from the use of propane‐1,2‐diol alginate (E 405) as a food additive. Therefore, the Panel concluded that there is no safety concern at the authorised use levels.