Could do better! A high school market survey of fish labelling in Sydney, Australia, using DNA barcodes
Could do better! A high school market survey of fish labelling in Sydney, Australia, using DNA barcodes
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作者：
A. Mitchell;Anna Rothbart;G. Frankham;Rebecca N. Johnson;L. Neaves
加工海产品不易根据物理特征识别，这使得该行业容易受到产品错误标签的影响（全球估计有5-30%的错误标签）。这既是一个食品安全问题，也是一个消费者保护问题，因为更便宜的物种可以取代更昂贵的物种。DNA条形码被证明是一个有价值的工具，用于验证鱼产品。我们与高中生合作，通过DNA条形码进行市场调查和随后的物种评估，以调查澳大利亚悉尼零售商使用的鱼类产品名称的准确性。方法从悉尼的两家零售商匿名购买了68种鱼类样本，以50种不同的常见名称出售。记录每个产品名称，并与澳大利亚鱼类名称标准（AFNS）进行协调。将样品进行DNA条形码化，并使用简化的学生数据门户界面将所得序列保存在在线生命数据条形码系统中。结果40%的鱼类名称不符合AFNS标准，但其中一半是拼写错误或供应商提供的信息超过了标准要求。另一半不符合规定的样本被赋予了AFNS上没有列出的通用名称。尽管缺乏标准化，但DNA条形码数据证实了零售商对93%的样本和90%的物种样本的识别。讨论我们报告的悉尼零售商的错误标签水平（7%的样本或10%的物种）与全球5- 30%的比例相比是有利的，但与澳大利亚唯一的DNA条形码鱼类认证研究相比是不利的，该研究发现霍巴特没有确认的错误标签。我们的研究样本主要是澳大利亚农产品，只有两家零售商，没有餐馆。我们有限的样本结果表明，虽然许多悉尼鱼零售商试图实施自愿鱼名标准，标准是不够的。由于澳大利亚75%的海鲜进口，而其他国家的餐馆通常比零售商的合规水平低，因此在概括这些结果之前需要进行更广泛的调查。DNA条形码是一种强大而简单的方法，由可访问的在线分析工具支持。将鱼类条形码纳入高中科学课程，为学生提供了宝贵的第一手科学研究经验，并汇集了新南威尔士州与遗传学和可持续性有关的不同课程。鉴于技术，设备和试剂现在很容易获得，我们预计未来澳大利亚的高中，公民科学家和消费者团体将更多地采用DNA条形码技术。然而，商业鱼类的DNA条形码诊断（数据和分析方法）仍有很大的进一步发展空间。
Background Processed seafood products are not readily identifiable based on physical characteristics, which leaves the industry vulnerable to high levels of product mislabelling (globally estimated at 5–30% mislabelled). This is both a food safety issue and a consumer protection issue as cheaper species could be substituted for more expensive species. DNA barcoding is proving to be a valuable tool for authentication of fish products. We worked with high school students to perform a market survey and subsequent species assessment via DNA barcoding to investigate the accuracy of fish product names used by retailers in Sydney, Australia. Methods Sixty-eight fish samples, sold under 50 different common names, were purchased anonymously from two retailers in Sydney. Each product name was recorded and reconciled with the Australian Fish Names Standard (AFNS). Samples were DNA barcoded and resulting sequences were deposited in the online Barcode of Life Data system using the simplified Student Data Portal interface. Results Forty percent of the fish names did not comply with the AFNS, however, half of these were either spelling errors or vendors supplied more information than the standard requires. The other half of the non-compliant samples were given common names not listed on the AFNS. Despite this lack of standardization, DNA barcode data confirmed the retailers’ identifications for 93% of samples and 90% of species sampled. Discussion The level of mislabelling we report for Sydney retailers (7% of samples or 10% of species) compares favorably with the global rates of 5–30%, but unfavorably with the only previous DNA barcode fish authentication study for Australia, which found no confirmed mislabelling in Hobart. Our study sampled mostly Australian produce, only two retailers and no restaurants. Results of our limited sample suggest that although many Sydney fish retailers attempt to implement the voluntary fish name standards, the standards are inadequate. As Australia imports 75% of its seafood, and in other countries restaurants generally show lower levels of compliance than retailers, broader surveys are needed before generalizing these results. DNA barcoding is a powerful yet simple method supported by accessible online analytical tools. Incorporation of fish barcoding into high school science classes provided students with valuable firsthand experience in scientific research and drew together different strands of the NSW curriculum relating to genetics and sustainability. Given the techniques, equipment, and reagents are now readily accessible, we expect to see greater uptake of DNA barcoding technology by high schools, citizen scientists and consumer groups in Australia in future. However, there remains much scope for further development of DNA barcode diagnostics (both data and analytical methods) for commercial fish species.