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A rapid and sensitive multiplex PCR assay was developed for simultaneous identification of the adulteration ingredients of chicken, duck and pork in beef. Specific primers for the mitochondrial genes of Cyt b, CO III, ATPase subunit 8/6 and Cyt b of chicken, duck, pork, and beef, respectively, were adopted in the assay. DNA exaction from meat samples was carried out by using magnetic nanoparticles as rapid separation substrates. The multiplex PCR assay showed that the limit of detection was 0.05% for each species. Moreover, the multiplex PCR specifically identified five beef samples adulterated with pork and one beef samples adulterated with chicken among the 35 commercial samples examined, indicating the practicability of this multiplex PCR method for identifying adulterated ingredients of chicken, duck, and pork in commercial beef products.

Fluorescence polarization (FP) signal is a self-referencing fluorescence signal, and it is less dependent on dye concentration and environmental interferences, which makes FP measurement a highly attractive alternative sensing technology to conventional fluorescent detection methods. Here we adopted a strategy for rapid increase of molecular weight to increase the FP signal for the detection of meat adulteration. The molecular weight of fluorescent labeled primers increased rapidly by slight preamplification, and the FP values were varied accordingly. We found a positive correlation between adulteration ratio and the FP signals. Detection limit for adulterated beef can be reached as low as 0.1% (wt %), meeting or better than the most detection requirements. On the basis of this proposed amplification-integrated FP method, both the standard samples and the commercial processed beef samples were successfully authenticated with satisfied results.

Rapid authentication of meat adulteration is of great importance for food safety. A new FRET-based self-signal-on fluorescent colorimetric PCR approach for rapid, sensitive and specific identification of horsemeat ingredient has been developed. A specific hairpin probe was designed and integrated with the forward primer for the detection of horsemeat. This specific hairpin sequence was designed to generate fluorescent signal only when primers are incorporated into the formation of double-stranded PCR product. The fluorescent signal of the PCR product is in a linear relationship with the proportion of horsemeat ingredient, and could be used for the quantitative detection of horsemeat ingredient in meat products without any post-treatment or analysis of the amplicons. Based on the fluorescent signal intensity, rapid and convenient detection of horsemeat ingredient in beef products was successfully achieved with satisfied specificity and sensitivity.

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