Development and validation of a liquid chromatographic tandem mass spectrometric method for the analysis of patulin in apple and apple juice

Simultaneous Monitoring and Decontamination of Pesticide Residues in Phytomedicine-Enriched Betel Leaf Utilizing QuEChERS-GC-MS/MS Technology to Safeguard Public Health

BACKGROUND

The presence of undesirable substances, including pesticides (xenobiotics) in betel leaf (Piper betel), is a great concern for consumers because it is chewed and consumed directly. To protect the consumer's health, a modified QuEChERS method for monitoring purposes and subsequent decontamination process has been developed.

OBJECTIVE

The goal of this work was to establish a multi-residue analytical method for monitoring nonpermitted organophosphorus pesticide residues in betel leaf, as well as cost-effective cleaning strategies.

METHOD

The homogenized 15 g samples (20 betel leaf samples collected in West Bengal, India) were extracted with a modified QuEChERS method using acetonitrile, reconstituted to acetone, and finally analyzed by GC-MS/MS. Possible decontamination techniques (such as tap water washing, 2% saltwater washing, and lukewarm water washing) were evaluated.

RESULTS

The limit of detection ranged from 0.003 to 0.005 mg/kg, and limit of quantification was 0.01 mg/kg. Recoveries ranged from 80 to 120% with RSDr 9%. One sample was found to contain three pesticides 4 to 7 times higher than MRLs. Suggested decontamination methods allowed reducing toxic traces below European limits.

CONCLUSIONS

The suggested approach is useful for determining pesticide residues in betel leaves quickly. Traditional techniques of processing betel leaves may reduce pesticide residues below regulatory limits.

HIGHLIGHTS

A multi-residue method and decontamination of pesticides in betel leaf using QuEChERS-GC-MS/MS technology with satisfactory method performance was achieved. Domestic decontamination techniques have a high efficacy in reducing pesticide residues from betel leaves, making them safe for human consumption.

Analysis of Patulin in Apple Products Marketed in Belgium: Intra-Laboratory Validation Study and Occurrence

Apple and apple derivatives (e.g., juices, puree) are the most important foodstuffs contaminated with patulin (PAT) in the human diet. To routinely monitor these foodstuffs and ensure that the PAT levels are below the maximum permitted levels, a method using liquid chromatography combined with tandem mass spectrometry (LC-MS/MS) has been developed. Afterwards, the method was successfully validated, reaching quantification limits of 1.2 μg/L for apple juice and cider, and 2.1 μg/kg for puree. Recovery experiments were performed with samples fortified with PAT in the range of 25-75 μg/L for juice/cider and 25-75 μg/kg for puree. The results show overall average recovery rates of 85% (RSD_r = 13.1%) and 86% (RSD_r = 2.6%) with maximum extended uncertainty (U_max, k = 2) of 34 and 35% for apple juice/cider and puree, respectively. Next, the validated method was applied to 103 juices, 42 purees and 10 ciders purchased on the Belgian market in 2021. PAT was not found in the cider samples, but it was present in 54.4% of the tested apple juices (up to 191.1 μg/L) and 7.1% of the puree samples (up to 35.9 μg/kg). When comparing the results to the maximum levels set by Regulation EC n° 1881/2006 (i.e., 50 μg/L for juices and 25 μg/kg for puree for adults, and 10 μg/kg for infants and young children), exceedances were observed in five apple juices and one puree sample, for infants and young children. Using these data, a potential risk assessment for consumers can be suggested, and it is found that the quality of apple juices and purees sold in Belgium needs further regular surveillance.

An Improved Analytical Approach Based on µ-QuEChERS Combined with LC-ESI/MS for Monitoring the Occurrence and Levels of Patulin in Commercial Apple Juices

Patulin (PAT) is a mycotoxin produced in fruits, especially in apples, by diverse fungal species that can be transferred into industrial apple juice during processing. An accurate, effective, and selective method has been validated for the quantification of PAT in different commercial apple juices by combining a modified µ-QuEChERS procedure with high-pressure liquid chromatography (LC) equipped with a triple quadrupole mass spectrometer (QqQMS). This sample extraction procedure reduced interference from the sugar-rich matrix, and the separation was performed using the C18 Atlantis T3 column within 10 min. PAT was found by MS with electrospray negative ionization (ESI−) in the mode of multiple reaction monitoring (MRM). The correlation coefficient (R2 = 0.999) satisfied the prerequisite of linearity for PAT in the concentration range of 2–50 μg/kg. The limits of detection (LOD) and quantification (LOQ) of PAT were 0.32 and 1.15 μg/kg, respectively, which were compliant with the maximum levels settled in Commission Regulation (EC) No. 1881/2006. The recoveries were within the 92–103% range, at three fortified levels of 2, 20 and 50 μg/kg, with relative standard deviations lower than 7%. Based on analytical validation, it was confirmed that the µ-QuEChERS/HPLC-MS/MS method is an enhanced, reliable, and quick approach for determination of PAT in apple juice. The current approach proposes reduced sample preparation and analysis time. In addition, it is economical, environmentally friendly, and simpler to implement in comparison to traditional approaches.

Mycotoxin Monitoring, Regulation and Analysis in India: A Success Story

Mycotoxins are deleterious fungal secondary metabolites that contaminate food and feed, thereby creating concerns regarding food safety. Common fungal genera can easily proliferate in Indian tropical and sub-tropical conditions, and scientific attention is warranted to curb their growth. To address this, two nodal governmental agencies, namely the Agricultural and Processed Food Products Export Development Authority (APEDA) and the Food Safety and Standards Authority of India (FSSAI), have developed and implemented analytical methods and quality control procedures to monitor mycotoxin levels in a range of food matrices and assess risks to human health over the last two decades. However, comprehensive information on such advancements in mycotoxin testing and issues in implementing these regulations has been inadequately covered in the recent literature. The aim of this review is thus to uphold a systematic picture of the role played by the FSSAI and APEDA for mycotoxin control at the domestic level and for the promotion of international trade, along with certain challenges in dealing with mycotoxin monitoring. Additionally, it unfolds various regulatory concerns regarding mycotoxin mitigation in India. Overall, it provides valuable insights for the Indian farming community, food supply chain stakeholders and researchers about India's success story in arresting mycotoxins throughout the food supply chain.

Chemical strategies for triggering the immune response to the mycotoxin patulin

Mycotoxins represent a major concern for human and animal health because of their harmful effects and high occurrence in food and feed. Rapid immunoanalytical methods greatly contribute to strengthening the safety of our food supply by efficiently monitoring chemical contaminants, so high-affinity and specific antibodies have been generated for almost all internationally regulated mycotoxins. The only exception is patulin, a mycotoxin mainly produced by Penicillium expansum for which such a target has not yet been achieved. Accordingly, no point-of-need tests commonly used in food immunodiagnostics are commercially available for patulin. In the present study, three functionalized derivatives conforming to generally accepted rules in hapten design were firstly tested to generate suitable antibodies for the sensitive immunodetection of patulin. However, these conventional bioconjugates were unable to elicit the desired immune response, so an alternative strategy that takes advantage of the high electrophilic reactivity of patulin was explored. Patulin was reacted with 4-bromothiophenol, and the obtained adduct was used to produce antibodies with nanomolar affinity values. These results demonstrated for the first time that targeting the adduct resulting from the reaction of patulin with a thiol-containing compound is a promising approach for developing user-friendly immunoanalytical techniques for this elusive mycotoxin.