Development and evaluation of a real-time PCR assay for the detection of bovine Milk in foods

was developed and evaluated for the detection of bovine DNA, specifically in the context of bovine milk in foods. Bovine milk was spiked at known concentrations into four complex food matrices -dark chocolate, vegan cookies, dairy-free muffins, and orange juice-chosen for their relevance to allergen recalls and robustness testing. Because milk is considerably lower in DNA concentration than other bovine tissues, beef was used as a control in a parallel set of spiking experiments to evaluate assay performance. The assay detected milk at concentrations as low as 100 ppm across food matrices, except in dark chocolate where internal controls indicate the presence of PCR inhibitors. Comparison between beef and milk spike data suggests that the lower sensitivity of the assay for milk detection is attributable to inherently low bovine DNA concentration in milk. This method should be used as a screening tool or in conjunction with immunoassays when food processing has compromised allergenic proteins.