Abstract:

A highly precise quantitative method based on the droplet digital polymerase chain reaction (ddPCR) technique
was developed to detect bovine and porcine ingredients in meat products. By using the ddPCR method, we found good linear
relationships between the raw meat weight and DNA content and between the DNA content and DNA copy number. Using
the DNA content as an intermediate value, we established the following formulae for calculating the weight of the original
raw meat from the specific DNA copy number: Mbeef = 0.062C - 0.943，Mpork = 0.045C - 1.72. By examining the mixed meat
samples of known compositions, we found that the final quantitative results for the mixed samples were similar to the true
raw meat weights, free from interference from exogenous species. Analysis of commercial samples showed that the ddPCR
quantification system enables determination of the proportions of bovine and porcine ingredients in meat products with good
practicability. Quantitative analysis indicates that ddPCR is highly precise in quantifying beef and pork in meat products and
therefore has the potential to be used in routine analysis and meat adulteration of various species.

Key words: droplet digital polymerase chain reaction, meat products, DNA copy number, meat adulteration