Multiplex-PCR Assay for Simultaneous Identification of Lamb, Beef and Duck in Raw and Heat-Treated Meat Mixtures

Rapid detection of adulterated lamb meat using near infrared and electronic nose: A F1-score-MRE data fusion approach

Individual detection techniques cannot guarantee accurate and reliable results when combatting the presence of adulterated lamb meat in the market. Here, we propose an approach combining the electronic nose and near-infrared spectroscopy fusion data with machine learning methods to effectively detect adulterated lamb meat (mixed with duck meat). To comprehensively analyse the data from both techniques, the F1-score-based Model Reliability Estimation (F1-score-MRE) data fusion method was introduced. The obtained results demonstrate the superiority of the F1-score-MRE method, achieving an accuracy rate of 98.58% (F1-score: 0.9855) in detecting adulterated lamb meat. This surpasses the performance of the traditional data fusion and feature concatenation methods. Furthermore, the F1-score-MRE data fusion method exhibited enhanced stability and accuracy compared with the single electronic nose and near-infrared data processed by the self-adaptive BPNN model (accuracy: 94.36%, 93.66%; F1-score: 0.9435, 0.9368). This study offers a promising solution to address concerns regarding adulterated lamb meat.

Development of Seven New dPCR Animal Species Assays and a Reference Material to Support Quantitative Ratio Measurements of Food and Feed Products

Laboratory testing methods to confirm the identity of meat products and eliminate food fraud regularly rely on PCR amplification of extracted DNA, with most published assays detecting mitochondrial sequences, providing sensitive presence/absence results. By targeting single-copy nuclear targets instead, relative quantification measurements are achievable, providing additional information on the proportions of meat species detected. In this Methods paper, new assays for horse, donkey, duck, kangaroo, camel, water buffalo and crocodile have been developed to expand the range of species that can be quantified, and a previously published reference assay targeting the myostatin gene has been modified to include marsupials and reptiles. The accuracy of this ratio measurement approach was demonstrated using dPCR with mixtures of meat DNA down to 0.1%. However, the limit of detection (LOD) of this approach is not just determined by the assay targets, but by the samples themselves, with food or feed ingredients and processing impacting the DNA yield and integrity. In routine testing settings, the myostatin assay can provide multiple quality control roles, including monitoring the yield and purity of extracted DNA, identifying the presence of additional meats not detected by the suite of species-specific assays and potentially estimating a sample-specific LOD based on measured copy numbers of the myostatin target. In addition to the myostatin positive control assay, a synthetic DNA reference material (RM) has been designed, containing PCR targets for beef, pork, sheep, chicken, goat, kangaroo, horse, water buffalo and myostatin, to be used as a positive template control. The availability of standardised measurement methods and associated RMs significantly improves the reliability, comparability and transparency of laboratory testing, leading to greater confidence in results.

Development of a multiplex PCR assay for the simultaneous detection of big blue octopus (Octopus cyanea), giant Pacific octopus (Enteroctopus dofleini), and common octopus (Octopus vulgaris)

Since octopuses are similar in appearance and can be processed into various forms, seafood fraud has been reported. In this study, we developed the PCR assay to simultaneously detect three octopuses (big blue octopus, giant Pacific octopus, and common octopus). Specific primer sets were designed based on COI gene. We observed that the specific PCR amplicon sizes were 84 bp for big blue octopus, 117 bp for giant Pacific octopus, and 166 bp for common octopus, respectively. This assay was then used to test for specificity and did not show cross-reactivity with 15 cephalopods families. The limit of detection of the multiplex PCR assay was 0.1 pg. Subsequently, 30 commercial food products were then monitored to evaluate the applicability of this assay. All products were specifically amplified, and three octopus species of interest were distinguished. Therefore, this assay can be used as an octopus authentication tool in the seafood industry.

A Multiplex PCR Assay Combined with Capillary Electrophoresis for the Simultaneous Identification of Atlantic Cod, Pacific Cod, Blue Whiting, Haddock, and Alaska Pollock

With an increased consumption of seafood products, food fraud with fish resources has been continuously reported. In particular, codfish has been exploited worldwide as a processed product in fresh, frozen, smoked, canned, or ready-to-eat dish forms. However, it is challenging to identify processed fish products after processing because of their similar morphological characteristics. Substitution and mislabeling of codfish among different species are also happening deliberately or unintentionally. Thus, it is necessary to distinguish cod species to prevent fish adulteration and food fraud. In this study, we developed a multiplex PCR for simultaneously identifying five cod species within Gadidae using capillary electrophoresis. Then, their species-specific primer sets were designed by targeting the mitochondrial cytochrome b gene. Subsequently, the amplicon sizes obtained were 237 bp, 204 bp, 164 bp, 138 bp, and 98 bp for Atlantic cod, Pacific cod, blue whiting, haddock, and Alaska pollock, respectively. The specificity of each primer was further tested using 19 fish species, and no cross-reactivity was observed. The limit of detection of this multiplex PCR assay was 1 pg. The developed multiplex PCR assay can be applied to 40 commercial food products successfully. This detection method will be efficient for managing seafood authentication by simultaneously analyzing multiple cod species.

Short targeting multiplex PCR assay to detect and discriminate beef, buffalo, chicken, duck, goat, sheep and pork DNA in food products

Food fraud is a global problem raising increased concerns during the past decades and food authenticity is now a burning issue. Beef, buffalo, chicken, duck, goat, sheep, and pork are heavily consumed meats bearing nutritional, economic and cultural/religious importance and are often found to be adulterated in raw and processed states. To authenticate these species, we developed and validated a highly specific multiplex (heptaplex) PCR assay targeting short length amplicons (73-263 bp) using seven pairs of species-specific primer sets targeting mitochondrial cytochrome b (cytb) and NADH dehydrogenase subunit 5 (ND5) genes. Specificity checking (in silico and in vitro) against 25 non-target species revealed no cross-species amplification. The developed multiplex assay was validated with various adulterated and heat-treated (boiled, microwaved and autoclaved) meatball products and were found to show high sensitivity and stability under all processing conditions. The assay was sensitive enough to detect 0.01-0.005 ng of DNA from raw meat and 0.5% (w/w) adulterated meat in mixed matrices. A market survey revealed mislabelling of 95% beef and 15% chicken products while pork products were found pure. Given some advantageous features including short sizes of amplicons, exceptional stability and superior sensitivity, the developed assay could be conveniently used for discriminatory detection of target species with a variety of raw meat as well as processed meat products undergoing extreme processing treatments.

A Simple and Reliable Single Tube Septuple PCR Assay for Simultaneous Identification of Seven Meat Species

Multiplex PCR methods have been frequently used for authentication of meat product adulteration. Through screening of new species-specific primers designed based on the mitochondrial DNA sequences, a septuple PCR method is ultimately developed and optimized to simultaneously detect seven species including turkey (110 bp), goose (194 bp), pig (254 bp), sheep (329 bp), beef (473 bp), chicken (612 bp) and duck (718 bp) in one reaction. The proposed method has been validated to be specific, sensitive, robust and inexpensive. Taken together, the developed septuple PCR assay is reliable and efficient, not only to authenticate animal species in commercial meat products, but also easily feasible in a general laboratory without special infrastructures.

Fraud in Animal Origin Food Products: Advances in Emerging Spectroscopic Detection Methods over the Past Five Years

Animal origin food products, including fish and seafood, meat and poultry, milk and dairy foods, and other related products play significant roles in human nutrition. However, fraud in this food sector frequently occurs, leading to negative economic impacts on consumers and potential risks to public health and the environment. Therefore, the development of analytical techniques that can rapidly detect fraud and verify the authenticity of such products is of paramount importance. Traditionally, a wide variety of targeted approaches, such as chemical, chromatographic, molecular, and protein-based techniques, among others, have been frequently used to identify animal species, production methods, provenance, and processing of food products. Although these conventional methods are accurate and reliable, they are destructive, time-consuming, and can only be employed at the laboratory scale. On the contrary, alternative methods based mainly on spectroscopy have emerged in recent years as invaluable tools to overcome most of the limitations associated with traditional measurements. The number of scientific studies reporting on various authenticity issues investigated by vibrational spectroscopy, nuclear magnetic resonance, and fluorescence spectroscopy has increased substantially over the past few years, indicating the tremendous potential of these techniques in the fight against food fraud. It is the aim of the present manuscript to review the state-of-the-art research advances since 2015 regarding the use of analytical methods applied to detect fraud in food products of animal origin, with particular attention paid to spectroscopic measurements coupled with chemometric analysis. The opportunities and challenges surrounding the use of spectroscopic techniques and possible future directions will also be discussed.

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.

Heptaplex Polymerase Chain Reaction Assay for the Simultaneous Detection of Beef, Buffalo, Chicken, Cat, Dog, Pork, and Fish in Raw and Heat-Treated Food Products

Species authentication of meat and fish products is crucial to safeguard public health, economic investment, and religious sanctity. We developed a heptaplex polymerase chain reaction assay targeting short amplicon length (73-198 bp) for the simultaneous detection and differentiation of cow, buffalo, chicken, cat, dog, pig, and fish species in raw and processed food using species-specific primers targeting mitochondrial cytb, ND5, and 16s rRNA genes. Assay validation of adulterated and various heat-treated meatball matrices showed excellent stability and sensitivity under all processing conditions. The detection limit was 0.01-0.001 ng of DNA under pure states and 0.5% meat in meatball products. Buffalo was detected in 86.7% (13 out of 15) of tested commercial beef products, while chicken, pork, and fish products were found to be pure. The developed assay was efficient enough to detect target species simultaneously, even in highly degraded and processed food products at reduced time.

Modern analytical methods for the detection of food fraud and adulteration by food category

This review provides current information on the analytical methods used to identify food adulteration in the six most adulterated food categories: animal origin and seafood, oils and fats, beverages, spices and sweet foods (e.g. honey), grain-based food, and others (organic food and dietary supplements). The analytical techniques (both conventional and emerging) used to identify adulteration in these six food categories involve sensory, physicochemical, DNA-based, chromatographic and spectroscopic methods, and have been combined with chemometrics, making these techniques more convenient and effective for the analysis of a broad variety of food products. Despite recent advances, the need remains for suitably sensitive and widely applicable methodologies that encompass all the various aspects of food adulteration. © 2017 Society of Chemical Industry.