Molecular detection of chicken and red-meat adulteration in locally processed meat products

Background: Food adulteration in processed meat products remains an important authenticity and consumer-protection problem because grinding, curing, seasoning and heating remove the visible identity of meat ingredients. DNA-based species detection is suitable for verifying declared meat species in products marketed as single-species or general meat products. 
Methods: A cross-sectional market-surveillance study was performed on 90 locally processed meat products, including beef burgers, beef sausages, minced red meat, kofta/kebab preparations and chicken-based processed products. Genomic DNA was extracted using a commercial food DNA extraction kit, assessed spectrophotometrically and amplified by conventional multiplex PCR targeting mitochondrial cytochrome b fragments for chicken, cattle and sheep. Positive reference meats, no-template controls, negative extraction controls and internal amplification controls were included in the workflow. PCR products were visualized by agarose gel electrophoresis and compared with declared label information. 
Results: Amplifiable DNA was obtained from 86 of 90 samples (95.6%). Among PCR-valid samples, the overall molecular-label discordance was 30.2%. Undeclared chicken DNA was the most frequent unexpected marker in red-meat-labelled products, especially in sausage and burger samples. Undeclared cattle/sheep DNA was detected less frequently in chicken-labelled products. Product categories differed numerically in discordance, but the chi-square comparison was not statistically significant. 
Conclusion: Species-specific multiplex PCR is a practical screening tool for detecting undeclared chicken and red-meat DNA in locally processed meat products. The workflow is suitable for routine food-control laboratories; however, quantitative qPCR or sequencing confirmation is recommended when regulatory decisions require estimation of adulterant mass fraction or legal enforcement.