Development and comparison of a porcine gelatin detection system targeting mitochondrial markers for Halal authentication

Abstract

This study aimed to compare the sensitivity of porcine-specific primers targeting different mitochondrial DNA for the detection of porcine gelatin in ramen stock powder designated "Halal" using SYBR Green I real-time PCR. Four mitochondrial DNA markers (D-loop, ATP8, ND5, and 12S rRNA) were used to detect the porcine gelatin DNA. Extraction of DNA from porcine gelatin and spiked mixtures was successfully performed using a DNeasy Mericon Food Kit. Each primer had high porcine specificity for D-loop, ATP8, and ND5 genes, but not the 12S rRNA gene. Also, the detection limit for each primer was tested in a serial dilution of porcine gelatin DNA (10, 1, 0.1, 0.05, 0.01, and 0.005 ng) and ramen stock powder spiked with porcine gelatin (1, 0.1, 0.05, and 0.025%). Assays targeting both D-loop and ND5 genes were able to detect a level as low as 0.01 ng, while the detection limit for the ATP8 gene was 0.05 ng in pure porcine gelatin. The detection limits of D-loop, ATP8, and ND5 genes were 0.05%, 0.1%, and 1% (w/w) in ramen stock powder spiked with porcine gelatin, respectively. In conclusion, a novel detection system targeting the mitochondrial D-loop was superior to the others and could be an effective and simple method to authenticate Halal products.