Pet Food

In recent years human nutrition has been greatly enriched due to the increased availability of goods and to deep lifestyle changes, involving socio-cultural, environmental and ethical aspects. This lead the food industry to experiment and propose a huge variety of products able to meet different nutritional needs, to offer additional services and to satisfy hedonistic demands.

Similarly, in the feed sector, the growing degree of anthropomorphism and the increase of pets wellness related pathologies, such as obesity, have led to the search for innovation in the choice of different formulations of pet-foods. The ingredients selection assumes an ever great appeal to the buyer and is the key element in the spread of feed formulation prepared according to the human food trends. In particular, feed palatability and tastiness is the basis of the growing consensus for the so-called elité products that often evoke in their formulations recipes of traditional national cuisine. Among them, the fish based (trout, salmon, white fishes, tuna-like and sardine-like fishes) super-premium cat feed consist mostly of single-dose portions generally imported from non-EU countries.

In the light of such a wide product range, feed traceability and labeling assume a fundamental role both for the protection of animal health and for the interests of the owner.

In this respect the introduction of the Reg. EC 178/2002 and 882/2004 equalized food and animal feed Business Operators (BO) responsibilities and has led to the harmonization of the official control on products intended for both human and animal consumption. Concerning feed hygiene and traceability requirements, the first legislations step is represented by EC Reg.183/2005, with the explicit exclusion of non food-producing animals. The regulatory framework has been further extended with the adoption of Regulation EC no.767/2009 which has sanctioned the application of all the principles of the previous regulations to all types of feed including those intended for pets.

As specified in the Reg EC n.767/2009, in order to ensure an informed purchase and a correct use of the feed, the Feed BO is the first and solely responsible of both the required information (time, modality of use and analytical composition of the product) and the optional elements highlighted on the label. Any claims and indications that could mislead the purchaser are strictly prohibited. However, especially for imported goods, since the use and publicizing of certain ingredients directly affects the cost of the product, it is plausible that “claiming” and misleading descriptions are used to achieve a greater market appeal.

The visual inspection alone applied to canned feed control is often ineffective due to the loss of species specific morphological characteristics. Among the alternative approaches proposed DNA based analysis has already proven to be an effective tool in the identification of species, also in canned fish products.

In this perspective the study was aimed to identify the fish species contained in 43 cat food products reporting the following valuable species among the ingredients:  “Bianchetto”/Whitebait (juvenile form of Sardine), Tuna, Bonito and Mackerel. Molecular analysis was performed on a portion of the mitochondrial 16srRNA gene already selected and tested as a universal marker for the identification of fish products in numerous studies.

For the analytical setting, considering the potentially high DNA fragmentation degree, primers capable of returning PCR products of variable length between 75 and 295 bp were designed and the obtained short sequences were analyzed running a BLAST (Basic Local Alignment Search Tool) analysis on GenBank and by performing a FINS (Forensically Informative Nucleotide Sequencing) analysis to verify the labeling information in the light of the European provisions.

As already observed in other studies, a short fragment of the 16srRNA gene represents a valuable tool in fish identification, even if with different levels of discriminatory power, and can be used on a wide variety of species. The results highlighted an impressive rate of mislabeling, affecting 100% of the whitebait and 40% of the fillets.

PUBLICATION

1. Armani A., Tinacci L., Xiong X., Castigliego L., Gianfaldoni D., Guidi A. “Fish species identification in canned pet food by BLAST and Forensically Informative Nucleotide Sequencing (FINS) analysis of short fragments of the mitochondrial 16s ribosomal RNA gene (16S rRNA)”. 10.1016/j.foodcont.2014.10.018. Food Control (Accepted for publication 14 October 2014).

2. Guidi A, Tinacci L, Armani A, Castigliego L., Gianfaldoni D, “Species identification in petfoods by using blast analysis of a fragment of the mitochondrial 16s ribosomal rna gene (16srRNA)”, LXVII Convegno della Società Italiana delle Scienze Veterinarie (SISVet), Brescia, Settembre 2013.