Duplex PCR-ELONA for the detection of pork adulteration in meat products

How Helpful May Be a CRISPR/Cas-Based System for Food Traceability?

Genome editing (GE) technologies have the potential to completely transform breeding and biotechnology applied to crop species, contributing to the advancement of modern agriculture and influencing the market structure. To date, the GE-toolboxes include several distinct platforms able to induce site-specific and predetermined genomic modifications, introducing changes within the existing genetic blueprint of an organism. For these reasons, the GE-derived approaches are considered like new plant breeding methods, known also as New Breeding Techniques (NBTs). Particularly, the GE-based on CRISPR/Cas technology represents a considerable improvement forward biotech-related techniques, being highly sensitive, precise/accurate, and straightforward for targeted gene editing in a reliable and reproducible way, with numerous applications in food-related plants. Furthermore, numerous examples of CRISPR/Cas system exploitation for non-editing purposes, ranging from cell imaging to gene expression regulation and DNA assembly, are also increasing, together with recent engagements in target and multiple chemical detection. This manuscript aims, after providing a general overview, to focus attention on the main advances of CRISPR/Cas-based systems into new frontiers of non-editing, presenting and discussing the associated implications and their relative impacts on molecular traceability, an aspect closely related to food safety, which increasingly arouses general interest within public opinion and the scientific community.

Identification of meat adulteration in minced meat samples labeled as beef and mutton in Tehran stores using duplex PCR

Food fraud and profiteering are becoming increasingly common in the meat industry. Therefore, it is essential to identify such practices to prevent consumer deception and maintain food safety. This study aimed to determine the contents of minced meat samples labeled as beef and mutton in retail stores across Tehran province, Iran, to identify instances of meat adulteration. To this end, this study randomly collected 300 minced meat samples labeled as beef and mutton from Tehran stores over 4 years (2018-2022) and analyzed them using duplex polymerase chain reaction (PCR). The results revealed that more than 95% of the samples only contained beef, while only 5% of the samples matched the label and contained a mixture of beef and mutton. This discrepancy between the label and actual contents could be attributed to the price difference between beef and mutton, providing a financial incentive for producers to maximize profits. Given the potential for meat adulteration, increased monitoring of meat products is necessary, including detailed tests such as PCR, which is a fast, easy, sensitive, specific, and highly effective method for detecting meat adulteration. The findings of this study can assist in developing effective strategies to prevent meat adulteration and maintain consumer confidence in the meat industry.

A multilocus DNA mini-barcode assay to identify twenty vertebrate wildlife species

The world faces significant challenges in preserving the diversity of vertebrate species due to wildlife crimes. DNA barcoding, an effective molecular marker for insufficient nuclear DNA, is an authentic and quick identification technique to trace the origin of seized samples in forensic investigations. Here, we present a multiplex assay capable of identifying twenty vertebrate wildlife species utilizing twenty species-specific primers that target short fragments of the mitochondrial Cyt b, COI, 16S rRNA, and 12S rRNA genes. The assay achieved strong species specificity and sensitivity with a detection limit as low as 5 pg of DNA input. Additionally, it effectively discriminated a minor contributor (≥1%) from binary mixtures and successfully identified of noninvasive samples, inhibited DNA samples, artificially degraded DNA samples, and case samples, demonstrating a sensitive, robust, practical and easily interpretable tool in screening, and investigating forensic wildlife crimes.

Meat Authenticity Made Easy: DNA Extraction-Free Rapid Onsite Detection of Duck and Pork Ingredients in Beef and Lamb Using Dual-Recombinase-Aided Amplification and Multiplex Lateral Flow Strips

Meat adulteration is a major global concern that poses a threat to public health and consumer rights. However, current detection techniques, such as quantitative polymerase chain reaction (qPCR) and gas chromatography-mass spectrometry, are time-consuming and require sophisticated equipment. In this study, we developed a rapid onsite identification method for animal-derived ingredients by utilizing a fast nucleic acid lysis buffer to expedite the release of sample nucleic acids and combined it with dual-recombinase-aided amplification (dual-RAA) technology and visual multiplex lateral flow strips (MLFSs). Our method successfully detected duck- and bovine-derived, porcine- and bovine-derived, duck- and ovine-derived, and porcine- and ovine-derived meat in a rapid 20 min onsite detection assay, with a detection limit of 101 copies/50 μL reaction system for target genes. Moreover, our method accurately detected adulterated meat with proportions as low as 1:999. These findings have significant implications for food safety and the protection of consumer rights.

Rapid analysis of meat floss origin using a supervised machine learning-based electronic nose towards food authentication

Authentication of meat floss origin has been highly critical for its consumers due to existing potential risks of having allergic diseases or religion perspective related to pork-containing foods. Herein, we developed and assessed a compact portable electronic nose (e-nose) comprising gas sensor array and supervised machine learning with a window time slicing method to sniff and to classify different meat floss products. We evaluated four different supervised learning methods for data classification (i.e., linear discriminant analysis (LDA), quadratic discriminant analysis (QDA), k-nearest neighbors (k-NN), and random forest (RF)). Among them, an LDA model equipped with five-window-extracted feature yielded the highest accuracy values of >99% for both validation and testing data in discriminating beef, chicken, and pork flosses. The obtained e-nose results were correlated and confirmed with the spectral data from Fourier-transform infrared (FTIR) spectroscopy and gas chromatography-mass spectrometry (GC-MS) measurements. We found that beef and chicken had similar compound groups (i.e., hydrocarbons and alcohol). Meanwhile, aldehyde compounds (e.g., dodecanal and 9-octadecanal) were found to be dominant in pork products. Based on its performance evaluation, the developed e-nose system shows promising results in food authenticity testing, which paves the way for ubiquitously detecting deception and food fraud attempts.

The Optimization of a Label-Free Electrochemical DNA Biosensor for Detection of Sus scrofa mtDNA as Food Adulterations

Fast, sensitive, and easy-to-use methods for detecting DNA related to food adulteration, health, religious, and commercial purposes are evolving. In this research, a label-free electrochemical DNA biosensor method was developed for the detection of pork in processed meat samples. Gold electrodeposited screen-printed carbon electrodes (SPCEs) were used and characterized using SEM and cyclic voltammetry. A biotinylated probe DNA sequence of the Cyt b S. scrofa gene mtDNA used as a sensing element containing guanine substituted by inosine bases. The detection of probe-target DNA hybridization on the streptavidin-modified gold SPCE surface was carried out by the peak guanine oxidation of the target using differential pulse voltammetry (DPV). The optimum experimental conditions of data processing using the Box-Behnken design were obtained after 90 min of streptavidin incubation time, at the DNA probe concentration of 1.0 µg/mL, and after 5 min of probe-target DNA hybridization. The detection limit was 0.135 µg/mL, with a linearity range of 0.5-1.5 µg/mL. The resulting current response indicated that this detection method was selective against 5% pork DNA in a mixture of meat samples. This electrochemical biosensor method can be developed into a portable point-of-care detection method for the presence of pork or food adulterations.

Simultaneous quantitative determination of residues of abamectin, ivermectin, albendazole and its three metabolites in beef and chicken by HPLC-PDA

Antimicrobial drugs are frequently used in a combination or shuttle way to cope with coinfection of bacteria or parasites and prevent drug resistance, thus the accurate quantification of multiple drug residues in animal-derived foods is crucial to ensure food safety. Here, a simple and efficient high-performance liquid chromatography-photodiode array (HPLC-PDA) method was established for the simultaneous quantitative screening of six common residues of antiparasitic drugs, including abamectin (ABM), ivermectin (IVM), albendazole (ABZ) and the three metabolites of ABZ in beef and chicken. The LODs and LOQs for six target compounds in beef and chicken are determined to be 3.2 to 12.5 µg/kg and 9.0 to 30.0 µg/kg, respectively. The calibration curves show good linearity (R² ≥ 0.9990) between the peak area and concentration. The recoveries from the fortified blank samples are all above 85.10%. Finally, the applicability of the HPLC-PDA method is successfully demonstrated by the real sample analysis.

Adulteration detection technologies used for halal/kosher food products: an overview

In the Islamic and Jewish religions, there are various restrictions that should be followed in order for food products to be acceptable. Some food items like pork or dog meat are banned to be consumed by the followers of the mentioned religions. However, illegally, some food producers in various countries use either the meat or the fat of the banned animals during food production without being mentioned in the label on the final products, and this considers as food adulteration. Nowadays, halal or kosher labeled food products have a high economic value, therefore deceiving the consumers by producing adulterated food is an illegal business that could make large gains. On the other hand, there is an insistent need from the consumers for getting reliable products that comply with their conditions. One of the main challenges is that the detection of food adulteration and the presence of any of the banned ingredients is usually unnoticeable and cannot be determined by the naked eye. As a result, scientists strove to develop very sensitive and precise analytical techniques. The most widely utilized techniques for the detection and determination of halal/kosher food adulterations can be listed as High-Pressure Liquid Chromatography (HPLC), Capillary Electrophoresis (CE), Gas Chromatography (GC), Electronic Nose (EN), Polymerase Chain Reaction (PCR), Enzyme-linked Immuno Sorbent Assay (ELISA), Differential Scanning Calorimetry (DSC), Nuclear Magnetic Resonance (NMR), Near-infrared (NIR) Spectroscopy, Laser-induced Breakdown Spectroscopy (LIBS), Fluorescent Light Spectroscopy, Fourier Transform Infrared (FTIR) Spectroscopy and Raman Spectroscopy (RS). All of the above-mentioned techniques were evaluated in terms of their detection capabilities, equipment and analysis costs, accuracy, mobility, and needed sample volume. As a result, the main purposes of the present review are to identify the most often used detection approaches and to get a better knowledge of the existing halal/kosher detection methods from a literature perspective.

Capture, detection and purification of dsDNA amplicons using a DNA binding protein on magnetic beads

Magnetic separation has been widely exploited for capture and detection of nucleic acids, including amplicons. Streptavidin-magnetic beads (SA-MB) are typically employed for this purpose, as well as in biosensing applications. However, remaining biotinylated primer in the amplification reaction can compete with labeled amplicon for binding to the beads. Also, the harsh conditions needed for elution of bound amplicons restrict their use for purification purposes. Herein we show that a sequence-specific DNA binding protein immobilized on magnetic beads can serve as an alternative to SA-MB for these applications. This is enabled by the high binding affinity of scCro DNA binding protein for its specific sequence and its ability to bind dsDNA but not ssDNA. This specific sequence is easily incorporated in the amplicon during amplification with an extended primer. The scCro-MB exhibited higher amplicon binding capacity and detection sensitivity compared to SA-MB when both synthetic and genomic DNA were used as templates for PCR. This resulted not only from increased protein load on the beads but also from minimized interference of excess labeled primer remaining in the unpurified amplification reactions. Finally, a proof-of-concept was provided for the use of the scCro-MB for PCR amplicon purification under mild elution conditions using salt.

Omics-Based Analytical Approaches for Assessing Chicken Species and Breeds in Food Authentication

Chicken is known to be the most common meat type involved in food mislabeling and adulteration. Establishing a method to authenticate chicken content precisely and identifying chicken breeds as declared in processed food is crucial for protecting consumers' rights. Categorizing the authentication method into their respective omics disciplines, such as genomics, transcriptomics, proteomics, lipidomics, metabolomics, and glycomics, and the implementation of bioinformatics or chemometrics in data analysis can assist the researcher in improving the currently available techniques. Designing a vast range of instruments and analytical methods at the molecular level is vital for overcoming the technical drawback in discriminating chicken from other species and even within its breed. This review aims to provide insight and highlight previous and current approaches suitable for countering different circumstances in chicken authentication.

Amplification Refractory Mutation System (ARMS)-PCR for Waxy Sorghum Authentication with Single-Nucleotide Resolution

Waxy sorghum has greater economic value than wild sorghum in relation to their use in food processing and the brewing industry. Thus, the authentication of the waxy sorghum species is an important issue. Herein, a rapid and sensitive Authentication Amplification Refractory Mutation System-PCR (aARMS-PCR) method was employed to identify sorghum species via its ability to resolve single-nucleotide in genes. As a proof of concept, we chose a species of waxy sorghum containing the wx^c mutation which is abundantly used in liquor brewing. The aARMS-PCR can distinguish non-wx^c sorghum from wx^c sorghum to guarantee identification of specific waxy sorghum species. It allowed to detect as low as 1% non-wx^c sorghum in sorghum mixtures, which ar one of the most sensitive tools for food authentication. Due to its ability for resolving genes with single-nucleotide resolution and high sensitivity, aARMS-PCR may have wider applicability in monitoring food adulteration, offering a rapid food authenticity verification in the control of adulteration.

Smartphone-based competitive immunoassay for quantitative on-site detection of meat adulteration

Rapid, sensitive, and portable analytical methods for on-site inspection of food fraud are now an urgent requirement to ensure food quality and satisfy the ethnic considerations of consumers. Hence, for the first time, a colorimetric smartphone-based immunoassay was developed for the on-site detection of pork adulteration in meat. In detail, the immunoassay was based on a competitive strategy in which immobilized standard porcine IgG competed with the target porcine IgG extracted in a single step from meat samples. The parameters involved in each step of the immunoassay conception and the digital colorimetric detection were carefully investigated and optimized. Using polystyrene microplates as ready-to-use stable and portable immunoplatforms, TMB as chromogenic substrate, smartphone as signal readout, and Image J software for image processing; the developed immunoassay was able to detect as low as 0.01% of pork in meat mixtures in a total assay time of 30 min. The selectivity of the immunoassay was evaluated for different meat species, and it was shown to selectively respond only to pork. Furthermore, excellent stability of the prepared immunological platform was demonstrated under extreme temperature conditions (50 °C), which confirms its high portability potential for in situ quantification of pork, while being relatively cost effective and non-laborious. The developed method also provides great precision (RSD < 6%) and accuracy (relative error< 6%). Given the universal use of smartphones as portable and affordable devices, such format of immunoassay could be a promising approach for rapid and sensitive real-time monitoring of food fraud.

Rapid point-of-care testing methods/devices for meat species identification: A review

The authentication of animal species is an important issue due to an increasing trend of adulteration and mislabeling of animal species in processed meat products. Polymerase chain reaction is the most sensitive and specific technique for nucleic acid-based animal species detection. However, it is a time-consuming technique that requires costly thermocyclers and sophisticated labs. In recent times, there is a need of on-site detection by point-of-care (POC) testing methods and devices under low-resource settings. These POC devices must be affordable, sensitive, specific, user-friendly, rapid and robust, equipment free, and delivered to the end users. POC devices should also confirm the concept of micro total analysis system. This review discusses POC testing methods and devices that have been developed for meat species identification. Recent developments in lateral flow assay-based devices for the identification of animal species in meat products are also reviewed. Advancements in increasing the efficiency of lateral flow detection are also discussed.

Dual platform based sandwich assay surface-enhanced Raman scattering DNA biosensor for the sensitive detection of food adulteration

Surface enhanced Raman scattering (SERS) DNA biosensing is an ultrasensitive, selective, and rapid detection technique with the ability to produce molecule-specific distinct fingerprint spectra. It supersedes the long amplicon based PCR assays, the fluorescence and spectroscopic techniques with their quenching and narrow spectral bandwidth, and the electrochemical detection techniques using multiplexing. However, the performance of the SERS DNA biosensor relies on the DNA probe length, platform composition, both the presence and position of Raman tags and the chosen sensing strategy. In this context, we herein report a SERS biosensor based on dual nanoplatforms with a uniquely designed Raman tag (ATTO Rho6G) intercalated short-length DNA probe for the sensitive detection of the pig species Sus scrofa. In the design of the signal probe (SP), a Raman tag was incorporated adjacent to the spacer arm, followed by a terminal thiol modifier, which consequently had a strong influence on the SERS signal enhancement. The detection strategy involves the probe-target DNA hybridization mediated coupling of the two platforms, i.e., the graphene oxide-gold nanorod (GO-AuNR) functionalized capture probe (CP) and SP-conjugated gold nanoparticles (AuNPs), consequently enhancing the SERS intensity by both the electromagnetic hot spots generated at the junctions or interstices of the two platforms and the chemical enhancement between the AuNPs and the adsorbed intercalated Raman tag. This dual platform based SERS DNA biosensor exhibited outstanding sensitivity in detecting pork DNA with a limit of detection (LOD) of 100 aM validated with DNA extracted from a pork sample (LOD 1 fM). Moreover, the fabricated SERS biosensor showed outstanding selectivity and specificity for differentiating the DNA sequences of six closely related non-target species from the target DNA sequences with single and three nucleotide base-mismatches. Therefore, the developed short-length DNA linked dual platform based SERS biosensor could replace the less sensitive traditional methods of pork DNA detection and be adopted as a universal detection approach for the qualitative and quantitative detection of DNA from any source.

Development and Validation of a Novel Five-Dye Short Tandem Repeat Panel for Forensic Identification of 11 Species

Species identification of unknown biological samples is of fundamental importance for forensic applications, especially in crime detection, poaching, and illegal trade of endangered animals as well as meat fraud. In this study, a novel panel was developed to simultaneously identify 10 different animal species (Gallus domesticus, Anas platyrhynchos domesticus, Ovis aries, Sus scrofa domesticus, Bos taurus, Equus caballus, Columba livia domestica, Rattus norvegicus, Mus musculus, and Canis lupus familiaris) and human beings by amplifying 22 short tandem repeat (STR) loci in a multiplex PCR using a set of five fluorescently labeled dyes. This novel 22-STR panel was validated by optimization of PCR conditions as well as species specificity, sensitivity, reproducibility, precision, DNA mixture, and tissue/organ consistency. The results of developmental validation showed that the 22-STR loci achieved high species specificity among 10 animal species and human beings, and the sensitivity of this panel was 0.09 ng. This 22-STR panel identified different meats in mixed samples, and the minimum detected mixture ratio in the current test was 10% (0.1 ng/1 ng). This sensitive, accurate, and specific 22-STR panel can be used for forensic species identification and the detection of meat fraud and adulteration.

Recombinase Polymerase Amplification Based Multiplex Lateral Flow Dipstick for Fast Identification of Duck Ingredient in Adulterated Beef

Simple Summary

The adulteration and authenticity of meat and meat products has become a global social problem. Beef is often intentionally adulterated with cheap meat. In order to ensure the authenticity of meat, and provide technical support to regulatory authorities, we developed a rapid and visual method to detect duck ingredient in adulterated beef. This method is implemented recombinase polymerase amplification (RPA) and multiplex lateral flow dipstick (MLFD) cascade. The whole RPA-MLFD reaction process can be finished within 35 min, and the results can be determined by naked eyes. RPA-MLFD was applied to simultaneously detect duck ingredient and beef ingredient without using additional instruments. An adulteration ratio as low as 5% of duck ingredient in beef can be easily measured. Moreover, we confirmed that our new method held good potential in the detection of commercially processed meat samples. Therefore, this study reports a useful animal derived meat adulteration detection method, which have potential application in future.

Abstract

Meat adulteration has become a global social problem. In order to protect consumers from meat adulteration, several methods have been developed to identify meat species. However, the conventional methods are labor-intensive, time-consuming and require instruments. In the present study, a rapid and visual method based on recombinase polymerase amplification (RPA) and multiplex lateral flow dipstick (MLFD) was developed to detect duck ingredient in adulterated beef. Using recombinase and strand displacement polymerase enable RPA to amplify different double-labeled DNA amplicons at room temperature, which can be further detected by MLFD. The whole reaction process can be finished within 35 min, and the results can be determined by naked eyes. As low as 5% of duck ingredient in adulterated beef can be easily measured. Moreover, we confirmed that our new method held good potential in the detection of commercially processed meat samples. In conclusion, this study reported a useful animal derived meat adulteration detection method, which have potential application in future.

Comparative review and the recent progress in detection technologies of meat product adulteration

Meat adulteration, mainly for the purpose of economic pursuit, is widespread and leads to serious public health risks, religious violations, and moral loss. Rapid, effective, accurate, and reliable detection technologies are keys to effectively supervising meat adulteration. Considering the importance and rapid advances in meat adulteration detection technologies, a comprehensive review to summarize the recent progress in this area and to suggest directions for future progress is beneficial. In this review, destructive meat adulteration technologies based on DNA, protein, and metabolite analyses and nondestructive technologies based on spectroscopy were comparatively analyzed. The advantages and disadvantages, application situations of these technologies were discussed. In the future, determining suitable indicators or markers is particularly important for destructive methods. To improve sensitivity and save time, new interdisciplinary technologies, such as biochips and biosensors, are promising for application in the future. For nondestructive techniques, convenient and effective chemometric models are crucial, and the development of portable devices based on these technologies for onsite monitoring is a future trend. Moreover, omics technologies, especially proteomics, are important methods in laboratory detection because they enable multispecies detection and unknown target screening by using mass spectrometry databases.

Molecularly Imprinted Nanogels Capable of Porcine Serum Albumin Detection in Raw Meat Extract for Halal Food Control

Accurate, simple, and valuable analytical methods for detection of food contamination are rapidly expanding to evaluate the validity of food product quality because of ethnic considerations and food safety. Herein molecularly imprinted nanogels (MIP-NGs), capable of porcine serum albumin (PSA) recognition, were prepared as artificial molecular recognition elements. The MIP-NGs were immobilized on a quartz crystal microbalance (QCM) sensor for detection of pork contamination in real beef extract samples. The MIP-NGs-based QCM sensor showed high affinity and excellent selectivity toward PSA compared to reference serum albumins from five different animals. The high PSA specificity of MIP-NGs led to the detection of pork contamination with a detection limit of 1% (v/v) in real beef extract samples. We believe the artificial molecular recognition materials prepared by molecular imprinting are a promising candidate for halal food control.

Methodology for identification and quantification of chicken meat in food products

Introduction. The problem of food adulteration is highly relevant today. Food manufacturers are increasingly replacing expensive raw materials with cheaper poultry. We aimed to develop an effective method for identification and quantification of chicken meat and egg products in multicomponent meat systems using real-time PCR. Study objects and methods. We studied native animal tissue, namely that of chicken, pork, beef, turkey, quail, duck, horse meat, rabbit, sheep, and goat. Standard samples were taken from pure fresh chicken muscle tissue. We also used raw, boiled, and powdered chicken eggs. For a semiquantitative analysis of chicken mass in the sample, we compared the threshold cycle (Ct) of chicken DNA and the threshold cycles of calibration samples. To ensure the absence of PCR inhibition, we used an internal control sample which went through all the stages of analysis, starting with DNA extraction. Results and discussion. We developed a methodology to qualitatively determine the content of chicken tissue in the product and distinguish between the presence of egg products and contamination on the production line. The method for chicken DNA identification showed 100% specificity. This genetic material was detected in the range of 0.1% to 0.01% of chicken meat in the sample. The efficiency of the duplex PCR system for chicken DNA detection was more than 95% (3.38 on the Green slope channel and 3.45 on the Yellow slope channel). The analytical sensitivity of the primers was 40 copies/reaction. Conclusion. Our methodology is suitable for analyzing multicomponent food products, raw materials, feed, and feed additives. It can identify the content of chicken meat at a concentration of up to 1%, as well as distinguish egg impurities from contamination of various origin. PCR allows differentiation between chicken meat and egg products.