Quantitative Detection of Donkey Hide Gelatin (Colla corii asini) Adulteration by Real-Time PCR on the Basis of Single-Copy Nuclear Genes

Abstract

Donkey hide gelatin (Colla corii asini) is well-known for its high nutritional value, especially for medicinal purposes. However, it is also a potential candidate for adulteration because of its low yield and high price. To quantitatively detect adulterated donkey hide gelatin with all possible mixed animal species, a real-time PCR approach on the basis of single-copy housekeeping nuclear reference primers was proposed in this study. For the system establishment, mixtures containing designated contents of pig hide with donkey hide were used to generate a calibration curve on the basis of the ratio of cycle threshold, CT (specificity/reference) with reasonable linearity (5 to 100%). Then, a set of experiments were performed on commercially available samples. The proposed PCR approach could specifically identify donkey hide from mixed animal products and quantify the content of donkey hide gelatin, thus facilitating control over this novel form of donkey hide gelatin adulteration.