A DNA Mini-Barcoding System for Authentication of Processed Fish Products.

Shadi Shokralla,Ian King,Mehrdad Hajibabaei,Rosalee S Hellberg,Sara M Handy

doi:10.1038/srep15894

Abstract

Species substitution is a form of seafood fraud for the purpose of economic gain. DNA barcoding utilizes species-specific DNA sequence information for specimen identification. Previous work has established the usability of short DNA sequences—mini-barcodes—for identification of specimens harboring degraded DNA. This study aims at establishing a DNA mini-barcoding system for all fish species commonly used in processed fish products in North America. Six mini-barcode primer pairs targeting short (127–314 bp) fragments of the cytochrome c oxidase I (CO1) DNA barcode region were developed by examining over 8,000 DNA barcodes from species in the U.S. Food and Drug Administration (FDA) Seafood List. The mini-barcode primer pairs were then tested against 44 processed fish products representing a range of species and product types. Of the 44 products, 41 (93.2%) could be identified at the species or genus level. The greatest mini-barcoding success rate found with an individual primer pair was 88.6% compared to 20.5% success rate achieved by the full-length DNA barcode primers. Overall, this study presents a mini-barcoding system that can be used to identify a wide range of fish species in commercial products and may be utilized in high throughput DNA sequencing for authentication of heavily processed fish products.

Highlights

Food fraud from species substitution is an emerging risk given the increasingly global food supply chain and potential food safety issues
The designated DNA barcode for animal species identification is a ~650-bp fragment of the mitochondrial gene coding for cytochrome c oxidase 1 (COI)[5,8]
The sequencing information generated from a small (≥ 100 bp) mini-barcode fragment of COI within the full-length DNA barcode region can provide the information required for identification of individual species with more than 90% species resolution[21,24,26]

Summary

Introduction

Food fraud from species substitution is an emerging risk given the increasingly global food supply chain and potential food safety issues. The need for accurately labelled food products and full disclosure of product composition has become more critical[4,5] One difficulty in this is the authentication process of different seafood products through examination of the physical appearance of specimens. The sequencing information generated from a small (≥ 100 bp) mini-barcode fragment of COI within the full-length DNA barcode region can provide the information required for identification of individual species with more than 90% species resolution[21,24,26]. We designed and optimized multiple primer sets to amplify mini-barcodes within the COI barcode region

Objectives

Methods

Results

Conclusion