DNA barcoding revealing seafood mislabeling in food services from Spain

Highlights

• This study included 313 samples in 204 mass caterers from 15 Spanish regions.

• DNA-barcoding has been successfully used for seafood products' mislabelling.

• One out of two mass caterer establishments served mislabeled meals in Spain.

• These results reveal the carelessness in the manipulation of seafood products.

Abstract

Commercialization of seafood is one of the most complex food chains at international level and it is therefore one of the food commodities most likely to face challenges related to fraud and authenticity. In this sense, several studies have revealed a high percentage of fraud for species substitution both at retail and food service level worldwide including European Union. Spain is one of the European countries with the highest consumption of fisheries and aquaculture products and it is therefore a very interesting region to evaluate the impact of seafood fraud in food services. The study presented in this paper is the first large-scale attempt to study the rate of seafood fraud in food services across Spain. A total of 313 samples were collected in 204 mass caterer outlets from 15 Spanish Autonomous Communities and successfully sequenced. DNA barcoding revealed that 50 % of the food services establishments sold mislabeled seafood. Dusky grouper and tope shark showed the highest mislabelling percentages ranging from 86 to 100 %. Overall results evidence the complexity of international seafood supply chains supported by the fact that many of the species reported substituting local species, are coming from Asian, South American and South African regions.

Introduction

Safe and trusted food value chains are needed to support human safety and health, as well as socio-economic growth at a time of rising global demand. The fisheries sector is crucial to meet food requirements worldwide (FAO, 2018). Fish consumption in the EU is currently 14.6 million tonnes per year (25 kg per capita per year) and it is expected to increase by some 1.5 million tonnes by 2030 (EU, 2018). However, almost 75 % of seafood products consumed in Europe are imported from outside Europe. Under this complex and global scenario necesary labeling rules to ensure the traceability of seafood products and eventually protect consumer‘s rights is essential. In this vein, European Union labeling law states that seafood products, among other characteristics, must be labeled with the complete scientific name of the species together with the commercial name. In some cases, the same commercial name corresponds to different species with diverse commercial value depending on countries and regions, what might cause confusion among consumers.

In a policy report published in 2013 by the European Parliament, seafood was identified and included in the top three of more fraudulent foodstuffs in Europe (Committee on the Environment, 2013). Seafood fraud can actually happen during catching, at the wholesaler, during processing, in the retail sector and in food services -defined as those businesses, institutions, and companies responsible for any meal prepared outside the home- including restaurants (Muñoz-Colmenero et al., 2016; Pardo et al., 2018). Food services is a sector especially vulnerable to fraudulent practices being at the end of the food chain. External morphological characteristics of the seafood are removed during filleting and the storage conditions and cooking process can also alter the colour. In this scenario, the consumer is unable to verify that what he has ordered from the menu is what is served on the plate. Although attending to the previously cited legislation, it is not mandatory to detail the scientific denomination for food services Nevertheless according to regulation EC No 1169/2011 the information of ingredients detailed in a product should accomplish transparency requirements.

In order to detect seafood fraud, reliable analytical methods are needed for species identification being mitochondrial DNA barcoding the most widely used technique for this purpose (Griffiths et al., 2014). As a matter of fact, the vast majority of the studies aimed at clarifying the mislabelling extent in the seafood production chain have been carried out by DNA barcoding (Pardo et al., 2016). Moreover, the great majority of these studies have commonly focused at the retail end of the supply chain, mainly supermarkets and fishmongers (Pardo et al., 2016). Specifically, different studies have focused on the seafood fraud incidences in the Spanish retail sector (Crego-Prieto et al., 2012; Espiñeira and Vieites, 2012; Garcia-Vazquez et al., 2011; Herrero et al., 2011b; Muñoz-Colmenero et al., 2016; Santaclara et al., 2015). It is worth mentioning that, in general, the increased awareness of industry to improve the transparency of the food chain, as well as the growth of the number of control activities launched by the European Official Control Bodies, have achieved a significant reduction in the number of misdescription incidences (Mariani et al., 2015). Nonetheless, in the food services sector the scenario is different as it has been revealed in some recent studies showing a mislabeling rate ranging from 25 to 65 % at Spanish restaurants (Gordoa et al., 2017; Horreo et al., 2019; Muñoz-Colmenero et al., 2016; Pardo et al., 2018). Similar findings have also been described in other European countries, Brazil, USA and Canada (Bénard-Capelle et al., 2015; Pardo et al., 2018; Staffen et al., 2017; Warner et al., 2019). In countries with a record of significant seafood mislabelling incidents, such as Spain, regular monitoring campaigns would be desirable to keep an update of the variations. To cope with this aim we decided to carry out a mislabeling monitoring campaign based on citizen science initiatives. This approach was previously and effectively applied in Europe and USA by research institutions (Bénard-Capelle et al., 2015; Horreo et al., 2019; Pardo et al., 2018; Warner et al., 2019) and even with students as collectors of samples for teaching activities (Borrell et al., 2016).

For this purpose, we have collected and barcoded for the first time a statistically representative number of seafood samples and establishments from several Spanish Autonomous Communities, to assess the degree of seafood mislabeling in Spanish food services.