Accurate determination of meat mass fractions using DNA measurements for quantifying meat adulteration by digital PCR

The alarming problem of meat adulteration emphasises the demand for accessible analytical approaches for food regulatory agencies to detect and, specially, to measure altered meat fractions. This study proposes a novel cross-species triplex droplet digital polymerase chain reaction (ddPCR) assay to simultaneously identify and quantify the ratios of pork/beef meat fractions from a total DNA content, including processed and autoclaved meat, without requiring a standard, achieving high sensitivity with a limit of quantification estimated at 0.1% (w/w) and a limit of detection down to 0.01% (w/w). A single copy nuclear gene, beta-actin, was employed as a target, accompanied with myostatin gene as a cross-species target to quantify the meat background. The duplex assay provided a simultaneous quantification of pork and myostatin, whereas the triplex assay was able to detect pork, beef and myostatin with a decrease of technical error, cost and time.