Detection of pork in meatballs using probe TaqMan Real-time Polymerase Chain Reaction

Abstract

This study aimed to develop a TaqMan Real-Time Polymerase Chain Reaction method, using a novel primer for detection of pork adulteration in meatballs. The study is important as it described a TaqMan method for product adulteration analysis. TaqMan is known to have a more specific result compared to SYBR green analytical method. Assay in the study combined species-specific primers and TaqMan probes to targeting 153 bp fragment of D-loop mitochondrial region of pork. A specificity test was conducted on fresh tissues of pork, beef, chicken, wild boar, dog, and mouse. Meatballs as samples were prepared from a mixture of pork-beef and wild boar-beef with concentrations as follows: 5%, 10%, 25%, 75%, 90%, and 100%. The linearity and sensitivity of the method were performed by measuring the amplification curve from the dilution series, namely 1000, 200, 100, 10, 5, 1, and 0.5 pg/μL of DNA, extracted from 100% pork meatballs. A repeatability test was conducted as many as six repetitions on 100% pork and 100% wild boar meatballs. This study showed that mitochondrial D-loop species-specific primers and TaqMan probes could identify the DNA of pork and wild boar on the fresh tissues. Additionally, it also resulted in a threshold cycle (Ct) of 17.02 and 17.95 for pork, 22.22 for wild boar, while the negative result for others. The detection limit has shown 5 pg in the meatball formulation. The Relative Standard Deviation (RSD) of repeatability was 1.936% for pork, while 2.140% for wild boar. The developed method was also applied to analyzing commercial meatballs. A TaqMan real-time PCR analytical method using specific primer targeting on 153 bp fragment of the D-loop mitochondrial region could be applied as a standard method for identifying pork and wild boar in food samples intended for halal authentication studies