Duplex droplet digital PCR (ddPCR) for simultaneous quantification of bovine and porcine gelatin in capsules.

Detection of bovine and porcine in gelatin-based products is important as species fraud and product mislabeling may have a detrimental impact on customers who have health, ethical, and religious concerns about animal products. The duplex droplet digital PCR (ddPCR) assay using double-quenched probes has been developed for quantification and detection of porcine and bovine DNA in gelatin capsules. A DNA mixture derived from gelatin was found to have a limit of detection as low as 0.001 ng/µl for porcine samples and 0.01 ng/µl for bovine samples. DNA from 12 other distinct species was tested with the bovine and porcine probes, showing high specificity for this method. The test was validated using fifty-five commercial supplement and pharmaceutical capsules, of which 17 were positive for bovine and/or porcine DNA. This study shows that the duplex ddPCR is reliable for routine analysis in the identification of bovine and porcine origins for gelatin capsules. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-022-01204-x.

Postmarket Laboratory Surveillance for Forbidden Substances in Halal-Certified Foods in Thailand.

Limited information exists regarding adulteration of Halal-certified food by substances forbidden under Islamic law (Haram substances). This study was conducted using forensic laboratory testing to investigate the prevalence of this type of adulteration. In this large-scale survey of Halal-certified food products randomly collected from markets in Thailand, 4,829 food samples from 10 food groups were tested in the laboratory for four potentially Haram substances: porcine DNA, porcine fatty acids, ethanol, and hydroxyproline (gelatin). No samples were adulterated with porcine DNA or fatty acids. However, 62 samples (approximately 1.3%) were positive for ethanol (>0.5% for non-naturally fermented products and >1% for naturally fermented products). The hydroxyproline concentration in the samples was compared with that of a negative control. Gelatin, as indicated by the presence of hydroxyproline, was the major suspicious substance found in these products. Further investigations are required to determine whether the gelatin is of Halal origin. These results from this first large-scale postmarket surveillance of Halal-certified food products for forbidden substances reveals the important role of forensic laboratory testing for supporting Halal supervision and certification. These findings provide useful information for government agencies seeking to encourage Halal compliance by food enterprises and for Muslim consumers and Halal food importers and exporters.