Edible DNA Barcode Labeling for Authenticity and Traceability of Foods

Introduction:  For the food industry, traceability is a critical issue throughout all stages of production, processing, and distribution. Most food producers go through significant effort and expense to provide products that are easily traced back to their source. However, other producers use intentional mislabeling to distribute inferior products. This damages markets and creates an elevated safety risk, because the fraudulent products are difficult to trace. The key to advancing global food supply chain efficiency, accountability, and security is through traceability.

Purpose: We have developed a technology for enhanced traceability and monitoring of adulteration by labeling foods with unique and edible DNA “barcodes.”

Methods: Synthetic DNA was mixed with carnauba wax and applied to fresh apples using a standard industrial coating process in a commercial packing facility. Similarly, cantaloupes were labeled with either one or both of two DNA barcodes (or none, as a control) in spiked carnauba wax through manual spraying in a commercial packing facility. Olive oil was also labeled with barcode DNA to gauge the ability of our technology to detect adulteration (by dilution), to evaluate the effects of edible DNA barcode on sensory qualities, and to assess the effects of olive maturity on DNA stability. Subsequently, DNA was extracted from the fruit wax coatings and olive oil, and qPCR was performed to measure recovery of barcode DNA. All samples were tested in triplicate.

Results: DNA was recovered from the surface wax of all 23 treated apples tested. DNA was also recovered from the waxed rinds of all 76 treated cantaloupes tested, with one false positive. Maturity level of olive oil had no measurable effect on DNA stability, and sensory testing showed no difference between tagged and untagged olive oil (P>0.05).

Significance: These results suggest that small amounts of DNA may be applied to food products using conventional processes, to facilitate traceability throughout the supply chain by distinguishing products specific to a producer and source.