Multiplex-PCR As a Rapid and Sensitive Method for Identification of Meat Species in Halal-Meat Products

A review of CRISPR-Cas and PCR-based methods for the detection of animal species in the food chain-current challenges and future prospects

Regular testing and systematic investigation play a vital role to ensure product safety. Until now, the existing food authentication techniques have been based on proteins, lipids, and nucleic acid-based assays. Among various deoxyribonucleic acid (DNA)-based methods, the recently developed Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) based bio-sensing is an innovative and fast-expanding technology. The CRISPR/Cas-9 is known as Clustered Regularly Interspaced Short Palindromic Repeats due to the flexibility and simplicity of the CRISPR/Cas9 site-specific editing tool has been applied in many biological research areas such as Gene therapy, cell line development, discovering mechanisms of disease, and drug discovery. Nowadays, the CRISPR-Cas system has also been introduced into food authentication via detecting DNA barcodes of poultry and livestock both in processed and unprocessed food samples. This review documents various DNA based approaches, in an accessible format. Future CRISPR technologies are forecast while challenges are outlined.

Multiplex PCR and 12S rRNA gene sequencing for detection of meat adulteration: A case study in the Egyptian markets

Recently, DNA-based methods have proved to be accurate, fast and sensitive for meat authentication. According to the European Union, the food safety standards require accurate and detailed composition information of the meat products. Therefore, an accurate, fast and cost-effective identification methodology is needed. In this study, multiplex PCR coupled with 12S rDNA sequencing was employed for the detection of meat adulteration in two red meat products (frozen beef liver and cold cut samples, respectively) in Egypt. Multiplex PCR allowed the identification of ruminant, poultry, pork, and donkey residuals in processed red meat products (cold cuts) in a single step PCR reaction. Preliminary uniplex PCR was performed to evaluate primers specificity using DNA extracted from the positive control samples. The primers produced specific fragments for ruminant, poultry, pork, and donkey as follows: 271, 183, 531 and 145 bp, respectively. Multiplex PCR revealed that none of the samples was contaminated by porcine or donkey residuals, but 62.5% of all tested processed beef samples contained poultry contaminants. The sensitivity of this method was 0.01 ng/μL for beef, poultry and donkey and 0.1 ng/μL for pig. Another promising finding is the identification of all frozen beef liver samples as a cattle species (Bos taurus) through PCR-sequencing of a short fragment of 12S rRNA gene. Finally, we recommend the employment of multiplex PCR and PCR-sequencing of 12S rDNA for quality control in routine analysis of processed and frozen meat products.

Development of a PCR-based assay for detection of Chinese mink tissue in meat products based on the mitochondrial DNA cytochrome-b gene

Species authentication of meat product origins has become an important subject for ensuring the health of consumers. Based on the cytochrome b gene, we developed a PCR-based assay kit for identification of Chinese mink tissues from 10 animal species in meat products, and to evaluate its quality indices including specificity, stability, sensitivity, and repeatability. Kits were made up of DNA extraction and PCR amplification systems based on species-specific, and universal primers. The reference meat mixtures and commercial samples were extracted by the kit and PCR technique was performed to identify the species of mink authenticity. The kit was effective after 20 repeated freeze-thaw cycles and it could be stored at -20 °C for 1 year. The sensitivity showed that a concentration as low as 0.1 ng/μL still can amplify the target band. The specificity test confirmed that the kit was 100% specific. The kit proved to be effective, stable, and reliable for extraction of efficient contents of the genomic DNA and routine analysis of Chinese mink source composition from meat products.