A Double-Gene Metabarcoding Approach for the Authentication of Shrimp Surimi-Based Products.

Background/objectives: Shrimp surimi-based products (SSPs) are composed of minced shrimp meat and are highly susceptible to food fraud as fish surimi. This study employed a double-gene metabarcoding approach to authenticate SSPs sold on Chinese e-commerce platforms.

Methods: 16S rRNA and 12S rRNA genes were amplified and sequenced from 24 SSPs. Mislabeling was evaluated based on the correspondence between the ingredients (only those of animal origin) reported on the products' labels and the molecular results.

Results: Overall, 87.50% of SSPs (21/24) were found to be mislabeled. The replacement of with other shrimp species was particularly noteworthy. Interestingly, in some SSPs, the primary species detected in terms of sequence abundance were not shrimp but fish, pork, chicken, and cephalopods, raising concerns regarding both health risks and ethical issues related to SSP consumption. The 12S rRNA sequencing results revealed that fish species like , , and were added to some SSPs in significant proportions, with certain products relying on fish priced from "Low" to "High" levels to substitute higher-cost shrimp. Notably, many fish species in SSPs were highly vulnerable to fishing, raising sustainability concerns. Overall, the high mislabeling rate in SSPs, as well as the detection of endangered fish species (), underscores significant quality control issues.

Conclusions: DNA metabarcoding has proven to be an effective tool for ingredient authentication in processed seafood.