RESUMO
Species substitution in meat products is a common problem reported worldwide. This type of food fraud is, typically, an intentional act for economic gain, using sources of low-priced meats in high-value meat products. Consequences include economic, health, and religious concerns. Highly sensitive and efficient techniques are thus required to detect meat species. This paper describes a method based on real-time PCR to detect 10 animal species (Bos taurus, Sus scrofa, Ovis aries, Capra hircus, Gallus gallus, Meleagris gallopavo, Bubalus bubalis, Equus caballus, Felis catus, and Canis familiaris) in meat product. The method combines species-specific and universal (used here as internal positive control) primers, and applies melt curve analysis for amplicon checking. Method accuracy was evaluated on 46 experimental meat mixtures and all species were correctly identified in all cases, at 1% test sensitivity. Analysis of 14 commercial meat products revealed that 6 of 14 samples had nondeclared bovine and/or chicken material. We performed an interlaboratory comparison using the reference meat mixtures and commercial samples, achieving 100% of reproducibility. The developed test proved to be effective and reliable for routine analysis of meat products. PRACTICAL APPLICATION: This paper describes a fast and reliable method for species detection in meat products based on real-time PCR. It can be applied for analysis of in natura or processed meat. The method proposed here can play an important role in controlling the origin of meat products, ensuring their quality and safety for the entire food industry-producers to consumers.
Assuntos
Contaminação de Alimentos/análise , Produtos da Carne/análise , Reação em Cadeia da Polimerase em Tempo Real , Animais , Búfalos , Gatos , Bovinos , Galinhas , Primers do DNA , Cães , Cabras , Cavalos , Limite de Detecção , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Análise de Sequência de DNA , Carneiro Doméstico , Especificidade da Espécie , Sus scrofa , PerusRESUMO
Medicinal plants are used throughout the world, and the regulations defining their proper use, such as identification of the correct species and verification of the presence, purity and concentration of the required chemical compounds, are widely recognized. Herbal medicines are made from vegetal drugs, the processed products of medicinal species. These processed materials present a number of challenges in terms of botanical identification, and according to the World Health Organization (WHO), the use of incorrect species is a threat to consumer safety. The samples used in this study consisted of the dried leaves, flowers and roots of 257 samples from 8 distinct species approved by the WHO for the production of medicinal herbs and sold in Brazilian markets. Identification of the samples in this study using DNA barcoding (matK, rbcL and ITS2 regions) revealed that the level of substitutions may be as high as 71%. Using qualitative and quantitative chemical analyses, this study identified situations in which the correct species was being sold, but the chemical compounds were not present. Even more troubling, some samples identified as substitutions using DNA barcoding contained the chemical compounds from the correct species at the minimum required concentration. This last situation may lead to the use of unknown species or species whose safety for human consumption remains unknown. This study concludes that DNA barcoding should be used in a complementary manner for species identification with chemical analyses to detect and quantify the required chemical compounds, thus improving the quality of this class of medicines.