P18 | Face-off: shark or pig? Molecular authentication of typical products made from shark stomach and intestines available on the Chinese market, purchased online

L. Tinacci¹, X. Zhang², A. Giusti¹, H. Kang² A, S. Li³ C, W. Deng⁴ D, Y. Li⁴, Z. Sun⁴, H. Peng⁴, L. Zou⁵, X. Li², A. Armani¹, J. Wen^4|5 | ¹Dip. Scienze Veterinarie, Università di Pisa; Pisa, Italy ²School of Food Science, Shaoguan University, Shaoguan, China; ³College of Marine Science, Beibu Gulf University, Qinzhou, China; ⁴School of Biology and Agriculture, Shaoguan University, Shaoguan, China; ⁵Technical center of Xining Customs, Xining, China; ⁶Guangdong Provincial Key Lab. of Utilization and Conservation of Food and Medicinal Resources in Northern Region, Shaoguan University, Shaoguan, China

Purpose. Accurate monitoring of the shark product supply chain plays a fundamental role in ensuring traceability, sustainability, and transparency for consumers. This study focused on evaluating the labeling and molecular authentication of foods that have been few-investigated, such as shark stomach (SH-s) and shark intestine (SH-i), available for purchase on the Chinese e-commerce market. In particular, the study aimed to assess the sustainability and potential implications for consumer health related to the identified species. Methods. The product search was conducted through the Taobao e-commerce platform. Sampling was conducted using a non-probabilistic approach. The price (converted to USD/kg) was recorded for each product and subsequently used to estimate the average commercial value for the two types of products. In the absence of a Chinese regulatory standard for the labeling of products marketed through e-commerce, the data reported in the product sheets available on the distribution platform were recorded. In addition, upon receipt of the products, the information on the label was verified against the requirements of the Chinese standard GB7718-2011 on the labeling of prepackaged foods. Molecular authentication of the products was carried out using DNA barcoding on a 655 bp region of the COI gene. Results. A total of 69 frozen products (48 SH-s and 21 SH-i) were selected from five provinces located along the southern and northeastern coasts of China. The market value of SH-s and SH-i was moderate (12.0–13.4 USD/kg). Analysis of online labeling revealed gaps in the commercial presentation of the products, which were designated exclusively by generic trade names (shark tripe or stomach, shark intestine), with no reference to the scientific name. Upon receipt, 91.3% of the products had no label; in the remaining 8.7%, partial non-compliance was found due to the absence of a list of ingredients. DNA barcoding analysis was successfully conducted on all 69 products, allowing molecular authentication of each product. The analysis found that 40.6% of the products belonged to the species Prionace glauca (blue shark) and 59.4% to Sus scrofa, constituting the first confirmed case of complete substitution of a fish matrix with one of terrestrial animal origin.Conclusions. The evidence gathered shows significant shortcomings in product traceability systems and raises concerns about possible economic fraud, serious violations of consumer rights, and potential risks to public health arising from the untraceable circulation of products that could contribute to the spread of infectious diseases and zoonotic diseases. These critical issues, exacerbated by the absence of a national regulatory standard for the labeling of pre-packaged and non-pre-packaged fish products, highlight the urgent need to strengthen traceability, consumer protection, and sustainability mechanisms throughout the fish supply chain.