Determination of mitochondrial cytochrome B gene sequence for red deer (Cervus elaphus) and the differentiation of closely related deer meats

Simultaneous identification of animal-derived components in meats using high-throughput sequencing in combination with a custom-built mitochondrial genome database

Currently, the inspection and supervision of animal ingredients relies primarily upon specific amplification-dependent methods, whose efficiency and accuracy are being seriously challenged by the increasing diversity and complexity of meat products. High-throughput sequencing (HTS) technology was employed to develop an alternative method to detect animal-derived ingredients in meat products. A custom-built database containing 2,354 complete mitochondrial genomic sequences from animals, an identification analysis pipeline based on short-sequence alignment, and a web-based server were built to facilitate this detection. The entire process, including DNA extraction, gene amplification, and sequencing, was established and optimized for both marker gene (part of the CYTB gene)-based detection and total DNA-based detection. Using simulated samples containing various levels of pig, cattle, sheep, chicken, rabbit, and mice ingredients, the detection capability and accuracy of this method were investigated. The results of this study indicated that the method is capable of detecting animal components in meats that are present at levels as low as 1%. Our method was then tested using 28 batches of real meat products such as raw meat slices, raw meat mince, cooked dried meat, cooked meat sausage, and other supermarket samples, with a traditional qPCR method as the control. The results demonstrated an accuracy of 97.65% for the qualitative detection method, which indicate that the developed method is reliable for the detection of animal components. The method is also effective for the identification of unknown food samples containing mixed animal components, which suggests a good future in application.

Sika deer (Cervus nippon)-specific real-time PCR method to detect fraudulent labelling of meat and meat products

Since game meat is more valuable and expensive than meat from domesticated animal species it is a potential target for adulteration. Analytical methods must allow the identification and quantification of meat species to be applicable for the detection of fraudulent labelling. We developed a real-time PCR assay for the authentication of sika deer (Cervus nippon) and products thereof. The primer/probe system amplifies a 71 bp fragment of the kappa-casein precursor gene. Since the target sequence contained only one sika deer-specific base, we introduced a deliberate base mismatch in the forward primer. The real-time PCR assay did not show cross-reactivity with 19 animal and 49 plant species tested. Low cross-reactivity was observed with red deer, fallow deer, reindeer and moose. However, with a ΔCt value of ≥11.79 between sika deer and the cross-reacting species, cross-reactivity will not affect the accuracy of the method. LOD and LOQ, determined by analysing serial dilutions of a DNA extract containing 1% (w/w) sika deer DNA in pig DNA, were 0.3% and 0.5%, respectively. The accuracy was evaluated by analysing DNA mixtures and DNA isolates from meat extract mixtures and meat mixtures. In general, recoveries were in the range from 70 to 130%.

An Updated Review of Meat Authenticity Methods and Applications

Adulteration of foods is a serious economic problem concerning most foodstuffs, and in particular meat products. Since high-priced meat demand premium prices, producers of meat-based products might be tempted to blend these products with lower cost meat. Moreover, the labeled meat contents may not be met. Both types of adulteration are difficult to detect and lead to deterioration of product quality. For the consumer, it is of outmost importance to guarantee both authenticity and compliance with product labeling. The purpose of this article is to review the state of the art of meat authenticity with analytical and immunochemical methods with the focus on the issue of geographic origin and sensory characteristics. This review is also intended to provide an overview of the various currently applied statistical analyses (multivariate analysis (MAV), such as principal component analysis, discriminant analysis, cluster analysis, etc.) and their effectiveness for meat authenticity.

Identification of species origin of meat and meat products on the DNA basis: a review

The adulteration/substitution of meat has always been a concern for various reasons such as public health, religious factors, wholesomeness, and unhealthy competition in meat market. Consumer should be protected from these malicious practices of meat adulterations by quick, precise, and specific identification of meat animal species. Several analytical methodologies have been employed for meat speciation based on anatomical, histological, microscopic, organoleptic, chemical, electrophoretic, chromatographic, or immunological principles. However, by virtue of their inherent limitations, most of these techniques have been replaced by the recent DNA-based molecular techniques. In the last decades, several methods based on polymerase chain reaction have been proposed as useful means for identifying the species origin in meat and meat products, due to their high specificity and sensitivity, as well as rapid processing time and low cost. This review intends to provide an updated and extensive overview on the DNA-based methods for species identification in meat and meat products.

Sequence analysis of mitochondrial 12S rRNA gene can identify meat species

In this study, sequence analysis of mitochondrial 12S rRNA has been applied for meat species identification. The procedure involves polymerase chain reaction (PCR) amplification of a fragment of mitochondrial (mt) 12S rRNA gene and sequencing of amplicons. Amplified product of mt 12S rRNA gene was 456 bp in size. Species sequenced include cattle (Bos indicus), buffalo (Bubalus bubalis), sheep (Ovis aries), goat (Capra hircus) and mithun (Bos frontalis). Sequences were compared with the reported sequences of low land anoa (Bubalus depressicornis), yak (Bos grunniens) and pig (Sus scrofa). There was no effect of routinely used additives or cooking temperature (72, 90, 120 and 180 °C) on the efficacy of PCR amplification. The closely related species like cattle and buffalo, sheep and goat could also be differentiated decisively by sequence analysis. Sequencing and analysis of mt 12S rRNA gene was, hence, found to be an ideal, authentic and unambiguous qualitative method for meat species identification.

Sequence characterization and polymerase chain reaction-restriction fragment length polymorphism of the mitochondrial DNA 12S rRNA gene provides a method for species identification of Indian deer

Characterization of species-specific molecular markers and development of a method for identification of Indian deer species is necessary to monitor illegal trade of parts and products for better conservation and management of the endangered species. In this investigation, we characterized the 12S rRNA gene sequence for differentiation of Indian deer species and developed a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP)-based method for their identification. Universal primers were used for the amplification of the mitochondrial 12S rRNA gene from genomic DNA of chital or spotted deer, hog deer, barking deer, sika deer, musk deer and sambar. PCR products of chital, hog deer and Himalayan musk deer were cloned and sequenced for the first time. Among the Indian deer species, more than 90% similarity was observed in the mitochondrial 12S rRNA gene. The sequences of the above deer species were restriction mapped with the help of Lasergene (DNAstar Inc., Madison, WI, USA). PCR amplicon of these deer species were subjected to restriction digestion with Rsa1, Dde1, Bsr1 and BstSF1 endonucleases that showed a species-specific RFLP pattern. This technique provides a reliable and efficient tool for identification of deer species using a variety of biomaterials.

Characterisation of peacock (Pavo cristatus) mitochondrial 12S rRNA sequence and its use in differentiation from closely related poultry species

1. Poaching of peacocks, the national bird of India, is illegal. People kill this beautiful pheasant bird for tail feathers and mix the meat with chicken or turkey. Differentiation of the meat of these species is essential in order to address the ambiguity about the origin of the sample. 2. The present study was carried out to investigate the use of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) of mitochondrial 12S rRNA gene for identification of these species. 3. Peacock mitochondrial 12S rRNA partial gene was amplified using universal primers, cloned and characterised. It was found to be 446 nucleotides long. 4. Sequence analysis revealed 86.8 and 84.1% similarity with reported turkey and chicken sequences, respectively. Sequence and phylogenetic analysis showed that the peacock is much closer to the turkey than the chicken. 5. PCR-RFLP of 446 bp amplicon using commonly available restriction enzymes AluI and Sau3AI produced a differential pattern for identifying these poultry species unambiguously.

PCR-RFLP authentication of meats from red deer (Cervus elaphus), fallow deer (Dama dama), roe deer (Capreolus capreolus), cattle (Bos taurus), sheep (Ovis aries), and goat (Capra hircus)

PCR-RFLP analysis has been applied to the identification of meats from red deer (Cervus elaphus), fallow deer (Dama dama), roe deer (Capreolus capreolus), cattle (Bos taurus), sheep (Ovis aries), and goat (Capra hircus). PCR amplification was carried out using a set of primers flanking a conserved region of approximately 712 base pairs from the mitochondrial 12S rRNA gene. Restriction site analysis based on sequence data from this DNA fragment permitted the selection of MseI, MboII, BslI, and ApoI endonucleases for species identification. The restriction profiles obtained when amplicons were digested with the chosen enzymes allowed the unequivocal identification of all domestic and game meat species analyzed in the present work.