Food Additives and Contaminants Part A-chemistry Analysis Control Exposure & Risk Assessment最新文献

In this work, we have developed a method to investigate the presence of four alkaloids and their migration potential from single-use, biodegradable Areca catechu-derived dinnerware. The seeds of Areca catechu palm, commonly referred to as the betel nut, are known to contain high concentrations of four alkaloids: arecoline, guvacoline, areciadine, and guvacine. Migration of these alkaloids into a food simulant was determined using a single-sided migration cell. The results indicate that carboxylic acid alkaloids, arecaidine, and guvacine, preferentially migrate under the experimental conditions which mimic the conditions of use for dinnerware.

Human exposure to polybrominated diphenyl ethers (PBDEs), a class of brominated flame retardants, can occur through consumption of contaminated foods. Since 2007, U.S. meat and poultry samples (beef, pork, chicken, turkey) have been collected every 5 years to assess PBDE levels and consumer exposure to seven PBDEs. Mean ∑PBDE concentrations from beef, pork, chickens, turkeys, dairy cows, and siluriformes (catfish) were 0.19, 0.48, 0.11, 0.60, 0.28 ng/g lipid weight (lw), and 2.5 ng/g wet weight (ww). The ΣPBDEs for all meat classes ranged from 0.005 to 17.7 ng/g lw. Comparison of the 2018-19 survey to the 2007-08 and 2012-13 surveys revealed an overall decrease in the median ΣPBDE residue for all four meat classes with significant reductions in the medians, at 40 - 45%, for pork, chicken, and turkey. As in the previous surveys, BDEs 47 and 99 had higher percentage contributions to the ΣPBDE concentrations than other PBDE congeners, which indicated the penta-BDE formulation was a likely exposure source for animals. An estimate of U.S. consumer daily intake of PBDEs from meat and poultry was 5.0 ng/day which is a decrease from the 2012-13 survey of 6.4 ng/day.

The neurotoxins of the saxitoxin family can be the origin of the human neurological syndrome of paralytic shellfish poisoning via contaminated marine bivalve vectors. A pre-chromatographic oxidation method is the official testing method in the EU, also known as the 'Lawrence method'. It involves several steps, including toxin extraction, solid-phase clean-up, and oxidation to produce fluorescent derivatives. Despite the manual peroxide oxidation involving four pipetting steps, high coefficients of determination were commonly obtained for the calibration curves of the respective toxin oxidation products. However, the 11-hydroxysulphate toxins dcGTX2 + 3, C1 + 2 and GTX2 + 3, often had slightly lower coefficients of determination (i.e. R² < 0.998) than their non-11-hydroxysulphate counterparts dcSTX, GTX5 and STX (i.e. R² > 0.998). Deviations of ±10 s from the respective standard reaction times, caused significant alterations in fluorescent yield for toxins quantified with peroxide but not for those quantified with periodate. The oxidation is an endothermal reaction, and its reaction rate is toxin-specific, with the N11-hydroxysulphate toxins having a slower reaction rate. This was confirmed by incubating GTX2 + 3 and STX at different reaction times. The incubation of toxins in a bivalve matrix also slows down the reaction in comparison with oxidation in dilute acetic acid, giving lower recoveries, as studied here in detail for dcGTX2 + 3. Circumventing the matrix effect by dilution is not possible, as 10% of matrix is enough to cause a reduction to half of the fluorescence yield of dcGTX2 + 3. When heating the N1-H toxins with peroxide, the increase in fluorescence yield is inversely proportional to the recovery values commonly found for each toxin.

Regulatory bodies aim to protect consumers from harmful substances. The use of certain antibiotics is prohibited in food-producing animals in the EU due to their potential detrimental effects on humans. Among these are nitrofuran antibiotics, which degrade rapidly so that their metabolites are used as markers in screening for their illegal use. The use of one metabolite, semicarbazide (SEM), as a marker for detecting the antibiotic nitrofurazone, has been criticized due to the many pathways it can be formed by and its natural occurrence in some food items. A recent change in the reference point of action (RPA) for SEM, as stated in Commission Regulation (EU) 2019/1871, due to a reassessment of sensitivity of the analyses, poses a problem for the export of heather honey in Norway. Norwegian heather honey seems to exceed the lowered RPA in numerous cases. Here we show that Norwegian heather honey samples, but not polyfloral 'summer' honey samples from the same hives, contain SEM. The simplest explanation for the demonstrated pattern is a natural source of SEM in heather honey, not the use of a banned antibiotic. Based on our results, we propose that an exception to the EU regulation should be added, exempting heather honey derived from Calluna vulgaris unless other nitrofurans or their metabolites are found together with SEM.

When manufacturing oral premixes, cross-contamination may occur between medicated and non-medicated feed leading to the exposure of food-producing animals to low concentrations that may result in antimicrobial residues in edible products. This project was designed to assess the level of antibiotic residues in edible pig tissues, faeces and plasma after exposure for 12 days to feed contaminated with sulphadimethoxine/trimethoprim (2% of the therapeutic dosage). Our results show that sulphadimethoxine concentrations can significantly exceed the maximum residue limits (MRL) in liver (618 ± 96 µg/kg) and kidneys (510 ± 73 µg/kg), and that putative metabolites can also be detected in the liver. Based on tissue and plasma data, a pharmacokinetic model was developed to assess which contamination rates would not result in residue concentrations above the MRL. Our simulations show that the contamination rate should remain below 0.2% of the therapeutic dose, i.e. far lower of the tolerated contamination rate.

Kanamycin (KANA) plays a key role in the treatment of bacterial infections and has been widely used in animal husbandry. However, its overuse causes antibiotic residues in animal-derived foods. Determination methods for KANA are urgently needed for food safety. Most of the developed fluorescent aptamer sensors for detecting KANA use parental aptamer (kana-Apt) as recognition unit. However, excessive bases tend to form secondary structures and lead to high background or nonspecific signals. In this study, two fluorescent sensors based on one (kana1-Apt) and two (kana1/kana2-Apt) split fragments were developed for KANA detection. The LODs of the kana1-Apt/ThT system and kana1/kana2-Apt/ThT systems were 4.88 nM and 4.53 nM, respectively. In addition, satisfactory recoveries of the kana1-Apt/ThT system and kana1/kana2-Apt/ThT system were obtained in the detection of KANA in milk, which were 97.6%-104.5% and 98.4%-105.9%, respectively. Moreover, the results indicated that the kana1-Apt fragment plays a critical role in recognition. In conclusion, the results of the present study provide a novel strategy for molecular detection based on split aptamers.

A rapid, sensitive and reliable analytical method for the simultaneous determination of fumonisin B₁ (FB₁) and fumonisin B₂ (FB₂) was developed and optimised using high performance liquid chromatography and fluorescence detection (HPLC-FLD) coupled with online pre-column derivatization using o-phthalaldehyde (OPA) and 2-mercaptoethanol (2-ME). This study focused on the optimisation of the online pre-column derivatization procedure, HPLC parameters, and sample pre-treatment. FB₁ and FB₂ in maize were extracted and purified using immunoaffinity column (IAC) and derived with OPA at room temperature. The OPA reagent was stable for 7 days, and OPA-derivatised products for 15 min. The excitation and emission wavelengths were 335 nm and 440 nm, respectively. Chromatography was performed using a C18 column and gradient elution at 1.0 mL min^-1 with acetonitrile and 0.1% acetic acid at pH 3.21. The LOD values of FB₁ and FB₂ were 0.10 and 0.26 mg kg^-1, respectively, comparable with or lower than those in other reports. The recoveries of FB₁ and FB₂ were between 85.6%-119.2%. The presented method is time-saving and robust, and successfully applied in determining FB₁ and FB₂ in maize.

The influence of temperature, relative humidity, and storage time on the production of Ochratoxin A by the fungus Aspergillus niger in dry parchment coffee was determined under controlled laboratory conditions. Additionally, the roasting curve that would achieve maximum reduction of OTA concentration in roasted coffee was evaluated. The objective was to establish strategies to reduce the risk of product contamination by this mycotoxin in coffee farms and its presence in coffee ready for consumption. For the analysis of the influence of temperature, relative humidity, and storage times on OTA production, sterilized coffee samples incubated with the A. niger strain were used. To obtain the roasting curves, coffee samples stored for 15 days at a temperature of 23 °C and relative humidity of 60% were employed. The OTA concentration of each study samples was quantified by ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS). The results obtained enabled: (1) The understanding of the conditions of temperature, relative humidity, and storage time that favor the production of the toxin by A. niger, thus allowing the development of coffee storage protocols that reduce grain contamination by this toxin, as it was found that increases in storage time and decreases in temperature and relative humidity to certain values are associated with increases in OTA concentration in the DPC. (2) Identifying the roasting curve whereby the coffee was subjected to temperatures from 180 °C to 208.8 °C for 11.23 min, achieving an OTA degradation of 76.4%. This curve serves as a guide for the adjustment of the temperatures and roasting times around the variables present in the process, achieving different roasting profiles, a significant reduction of OTA without affecting the quality of the coffee, and facilitating different chemical, physical, and organoleptic characteristics that can accommodate consumers' tastes and ensure a safe beverage.

Indole-3-acetic acid (IAA) is a natural plant hormone which can also be used as a plant growth regulator. However, its usage on crops is not permitted in the EU, with a maximum residue limit (MRL) currently set at 0.1 mg kg^-1 for all food commodities. As available data on the occurrence of IAA in food commodities are limited, this work aims at evaluating the amount of IAA in important food commodities such as coffee and cereals, but also selected processed ingredients such as cocoa and malt. In total, 133 samples representing 18 different food commodities were analysed for the occurrence of free IAA using a liquid chromatography high resolution mass spectrometry method. IAA was detected in all samples except malt powders and tomatoes. The analysed crops were either grown under conventional, organic, or strictly controlled (i.e. excluding the use of IAA as pesticide/plant growth regulator) farming conditions. No significant differences in the amounts of IAA were found in crops grown under the three different farming conditions. A high percentage of the samples (63%) showed levels of free IAA above the EU MRL. We therefore conclude that the natural abundance of IAA was not properly assessed prior to the establishment of some current EU MRLs. Based on the natural occurrence of IAA in a wide range of foods; we question the need for an MRL for IAA in plant-based foods.

Organophosphate esters (OPEs) have raised great concerns in recent years. However, information regarding their occurrence in infant formula remains limited. Thus, thirty-two OPEs were measured in infant formula sold in Shanghai, China in 2023. The results showed that OPE occurrence in infant formula was widespread. The median concentrations of organophosphate diesters, organophosphate triesters, and total OPEs were 2.28, 5.20, and 8.63 ng/g, respectively. Tris(2-chloroisopropyl) phosphate (TCPP) showed the highest median concentration (1.95 ng/g), followed by triethyl phosphate, bis(1-chloro-2-propyl) phosphate (BCPP), tri-isobutyl phosphate, and triphenyl phosphate (0.532-0.581 ng/g). The dominant chloro-OPEs (TCPP and BCPP) were regional-specific. Compared to corresponding triesters, the diester concentrations were often lower, except for bis(2-butoxyethyl) phosphate and tributoxyethyl phosphate. Additionally, five novel OPEs with phenyl groups were identified, showing high detection frequencies and comparable concentrations to TCPP. Raw materials and food processing methods might affect individual OPEs. The estimated daily intakes (EDIs) ranged from 62.3 to 355 ng/kg bw/day. The highest EDI occurred in infants of 0-6 months of age but posed no obvious health risk for infants and toddlers. Further studies are still needed to evaluate the possible health implications arising from the novel OPEs and their metabolites, as well as the potentially synergistic effects.