Detection of polyphosphates in seafood and its relevance toward food safety

Bisphenol analogues in infant foods in south China and implications for infant exposure

Bisphenol analogues (BPs) are commonly used as modifiers, stabilizers and photo-initiators in polymer materials, including those used in food packaging. Compared to adults, infants are more sensitive to chemicals because their bodies are growing and not fully developed. Therefore, it is essential to determine the concentrations of BPs in common infant foods to assess infant exposure and prevent hazards. We collected 54 infant formula (IF) samples, 90 complementary food (CMF) samples and 62 breastmilk samples from breastfeeding women in south China. Tandem mass spectrometry coupled to liquid chromatography separation (HPLC-MS/MS) was used to detect the concentrations of 8 BPs in the three types of food samples. The estimated daily intake (EDI) of infants was also assessed. The results showed that the detection frequency of bisphenol F (BPF), bisphenol S (BPS), bisphenol AF (BPAF) and bisphenol AP (BPAP) were relatively high among the different infant foods. BPF, BPP and BPS were predominant among the detected BPs. The lowest 95th EDI for BPA was 0.67 ng kg-bw-1 day-1, exceeding the tolerable daily intake (TDI) limit for BPA set by the European Food Safety Authority in 2023. Thus, BP exposure is a significant risk to infants. More attention should be paid to the presence of BPs in daily use products and food, and intake limits should be set for BPs other than BPA.

Ratiometric fluorescent detection of total phosphates in frozen shrimp samples using catalytic active Zr(IV) modified gold nanoclusters

Phosphate salts are important food additives in a variety of foods. In this study, the Zr(IV) modified gold nanoclusters (Au NCs) were prepared for ratiometric fluorescent sensing of phosphate additives in seafood samples. Compared with bare Au NCs, the synthesized Zr(IV)/Au NCs showed stronger orange fluorescence at 610 nm. On the other hand, the Zr(IV)/Au NCs retained the phosphatase-like activity of Zr(IV) ions and could catalyze the hydrolysis of fluorescent substrate 4-methylumbelliferyl phosphate to produce blue emission at 450 nm. The addition of phosphate salts could effectively inhibit the catalytic activity of Zr(IV)/Au NCs, resulting the fluorescence decrease at 450 nm. However, the fluorescence at 610 nm almost unchanged upon the addition of phosphates. Based on this finding, the ratiometric detection of phosphates using the fluorescence intensity ratio (I₄₅₀/I₆₁₀) was demonstrated. The method has been further applied for sensing total phosphates in frozen shrimp samples with satisfactory results.

Fly-antennae-inspired biomass-based fluorescent platform for NH3 quantitative detection and visual real-time monitoring of seafood spoilage

Traditional strategies for quantitative detection of NH₃ and monitoring of seafood spoilage still have some pervasive issues of cumbersome operation, time-consuming, high-cost, and inefficient real-time monitoring, and visualization. Integration of biomass-based materials and aggregation-induced emission (AIE) fluorescence probes exhibit conceivable potential in seafood detection and environmental monitoring. Herein, a fly-antennae-inspired biomass-based solid-state fluorescent platform (PAA-FP) with effective, easy-to-use, reusable, low-cost and highly sensitive characteristics is nanoengineered for NH₃ quantitative detection (detection limit = 0.5 ppm) and visual real-time monitoring of seafood spoilage using smartphones. The PAA-FP possesses an anticipative "fly-antennae-like" microstructure and offers selective recognition of NH₃ by naked eyes in daylight with excellent solid-state fluorescence properties. Moreover, PAA-FP is simply reused at least 5 times after AcOH fumigation. Comprehensive application experiments substantiate that PAA-FP successfully achieves quantitative detection of NH₃ and realizes the visual real-time daylight monitoring of food spoilage using a simple color recognizing smartphone software. The present study demonstrates an effective fabrication strategy to explore various multifunctional biomass-based materials for sensing hazardous and noxious substances.

Analysis of added phosphates in hake fillets by ion-exchange chromatography: A case study of false positives induced by nucleotides coelution

This study aimed to optimize an ion-exchange chromatography method for an accurate quantification of phosphates. Coelution of nucleotides was detected following the quantification of small amounts of di- and trimetaphosphates in hake fillets. In some samples, triphosphates were added to the glaze ice, therefore, defrosting waters (glaze ice + drip loss of fillets) should be analyzed for an effective assessment of the use of phosphates in seafood. Even low amounts of adenosine 5'-diphosphate (ADP) and inosine 5'-monophosphate (IMP) triggered false positive results for P₂O₇^4- and P₃O₉^3-. Keeping the initial isocratic conditions for longer was crucial for the separation of ADP from P₂O₇^4- and of IMP from P₃O₉^3-. The improved method showed that in general, hake fillets did not have diphosphates, and trimetaphosphates were residual. Triphosphates were clearly added in only four defrosting waters, and in most of the remaining ones, diphosphates and trimetaphosphates contents corresponded to false positive results.

Suspect screening and untargeted analysis of veterinary drugs in food by LC-HRMS: Application of background exclusion-dependent acquisition for retrospective analysis of unknown xenobiotics

The presence of veterinary drug and pesticide residues in food products pose considerable threats to human health. Monitoring of these residues in food is mainly carried out using targeted analysis by triple quadrupole mass spectrometry. However, these methods are not suitable for suspect screening and untargeted analysis of unknowns. The main objectives of this study were to develop a new high-resolution mass spectrometry (HRMS)-based analytical strategy for retrospective analysis of suspect and unknown xenobiotics and to evaluate its performance in the tentative identification of 48 veterinary drugs as "unknowns" spiked in a pork sample. In the analysis, a newly developed background exclusion data-dependent acquisition (BE-DDA) technique was employed to trigger the product ion (MS/MS) spectral acquisition of the "unknowns", and an in-house precise-and-thorough background-subtraction (PATBS) technique was applied to detect these "unknowns". Results showed that untargeted data mining of the acquired LC-MS dataset by PATBS was able to find all the 48 veterinary drugs and 46 of them were triggered by BE-DDA to generate accurate MS/MS spectra. The dataset of recorded accurate full-scan mass and MS/MS spectra of all the xenobiotics of the test pork sample is defined as the xenobiotics profile. Searching the xenobiotic profile of the test pork sample using mass spectral data of selected veterinary drugs (as suspects) from the mzCloud spectral library led to the correct hits. Searching against the mzCloud spectral library using the mass spectral data of selected individual veterinary drugs (as unknowns) from the xenobiotics profile tentatively confirmed their identities. In contrast, analysis of the same sample using ion intensity-data dependent acquisition only recorded the MS/MS spectra for 34 veterinary drugs. In addition, a data independent acquisition method enabled the acquisition of the fragment spectra for 44 veterinary drugs, but their spectral data displayed only one or a few true product ions of individual analytes of interest along with many fragments from coeluted biological components and background noises. This study demonstrates that this analytical strategy has a potential to become a practical tool for the retrospective suspect screening and untargeted analysis of unknown xenobiotics in a biological sample such as veterinary drugs and pesticides in food products.

Perchlorate and chlorate in breast milk, infant formulas, baby supplementary food and the implications for infant exposure

Perchlorate and chlorate are ubiquitous pollutants in various types of foodstuffs, drinking water and environmental compartments. They have raised great concerns due to potential adverse effects on human thyroid functions. Dietary intake is considered as the predominant pathway for human exposure to perchlorate and chlorate. Nevertheless, data on human exposure to the chemicals above remain limited, particularly for the most vulnerable populations such as infants. In the present study, 62 breast milks, 53 infant formulas, 88 baby supplementary food and 50 tap water samples were collected in South China and the levels of perchlorate and chlorate were measured in these samples. Perchlorate and chlorate were frequently detected in more than 90% of measured samples. In these different types of samples, the median concentrations of perchlorate were 0.65 μg/L, 0.61 μg/kg, 0.56 μg/kg and 1.18 μg/L, respectively, while the median concentrations of chlorate were 1.73 μg/L, 2.48 μg/kg, 2.67 μg/kg and non-detected, respectively. Health risk assessment using hazard quotient suggested that perchlorate and chlorate exposure in the sampled baby food are not expected to increase the risk of an adverse health effect. To our knowledge, this is the first study simultaneously investigating perchlorate and chlorate exposure in Chinese infants via food intake.

Undeclared (Poly)phosphates Detection in Food of Animal Origin as a Potential Tool toward Fraud Prevention

(Poly)phosphates are approved as water-preserving and emulsifying agents that improve the appearance and consistency of many food products. The labelling of added (poly)phosphates is essential for protecting vulnerable population groups and to prevent unfair trade practices resulting in economic fraud. The problems with (poly)phosphates' utilisation concerns both analytical and legislative issues, such as: (1) their straightforward detection; (2) excessive addition altering freshness perception and misleading consumers; (3) uncontrolled usage increasing foodstuff weight; (4) application in products where they are not permitted; and (5) no indication on the label. Bearing all these issues in mind, the main purpose of this study was the quantification and screening of the (poly)phosphates profile in meat, marine and dairy products (160 samples), of which 43 were without declared (poly)phosphate treatment. Analysis was completed by high-performance ion-exchange chromatography either with conductometric detection or coupled to Q-Exactive Orbitrap high-resolution mass spectrometry. Although the (poly)phosphates profiles varied greatly according to species and processing type, the following criteria for detection of illicit treatment were established: high orthophosphate level, quantified short-chain (poly)phosphate anions and the presence of long-chain forms. In conclusion, the instrumental platforms used in this study can be recommended to inspection bodies as reliable methods for the detection of food adulteration with (poly)phosphates.

Online extraction based on ionic covalent organic framework for sensitive determination of trace per- and polyfluorinated alkyl substances in seafoods by UHPLC-MS/MS

The ionic covalent organic framework (TPB-BFBIm-iCOF) was facilely synthetized by the size-controllable confinement method and chosen as the online solid phase extraction (SPE) adsorbent. This adsorbent showed fast adsorption equilibrium (5 min) and high adsorption capacity (87.7-140.8 mg g^-1) for the per- and polyfluorinated alkyl substances (PFASs). The TPB-BFBIm-iCOF microsphere revealed the satisfactory enrichment performance for PFASs by means of the electrostatic interaction, hydrophobic effect and ordered channel structure. After extraction, the loaded TPB-BFBIm-iCOF-online SPE column was eluted and applied to the ultrahigh performance liquid chromatography tandem mass spectrometry analysis. Under the optimum conditions, the method displayed satisfactory linearity (R² ≥ 0.9910) and low limits of detection (≤0.0017 ng g^-1) for five seafoods. The relative recoveries of PFASs were 85.3%-109.4% with the relative standard deviation ≤ 9.9%. The method exhibited potential value in monitoring the toxicokinetics and environmental behaviors of PFASs.

Safety assessment of condensed phosphate intake from fishery and processed marine food products in Korea with respect to gender, age, and region

Condensed phosphates are used as food additives, especially in marine products and meat, to improve food quality. The import and consumption of fishery and processed marine food products in Republic of Korea have reportedly increased by ~5 per cent annually. However, processed marine food products are often intentionally adulterated with excessive amounts of condensed phosphates to increase their weight. Excessive intake of condensed phosphates via consuming processed marine food products can lead to various adverse effects on human health due to anionic imbalance. Herein, we conducted a safety assessment of condensed phosphates in 14 types of fishery and processed marine food products in Korea for the first time. Subgroup analysis of various factors including gender, age, and region was also performed, and the risk level of exposure for each group was estimated. Safety assessments by age and gender indicated that infants were at the highest risk. In the regional safety assessment, Chungnam, the most inland region, showed the lowest risk. For both the general and the high-intake groups (95th percentile) in all classifications, the risk was lower (<20 per cent) than the international standard, and the phosphorus content of the 14 types of processed marine products in Korea was confirmed to be safe for human consumption.