Identification of hare meat by a species-specific marker of mitochondrial origin

Effects of Sex and Hunting Season on Carcass and Meat Quality Characteristics of the Brown Hare (Lepus europaeus)

The objective of the study was to determine the effects of sex and hunting season on the carcass, meat and fat quality of hunted brown hares (Lepus europaeus). Twenty-two hares of both sexes hunted in winter (December) during two hunting seasons in accordance with the law on hunting in Lithuania were evaluated using reference methods The data were subjected to two-factor analysis of variance in the general linear (GLM) procedure. No significant differences in carcass measurements and muscularity or internal organs between the sexes of brown hares were found; however, the hunting season appeared to affect the size of hares. The biceps femoris (BF) thigh muscle of males had lower (p < 0.05) dry matter content and higher (p < 0.05) drip loss compared with females. The hunting season demonstrated an effect (p < 0.001) on protein and hydroxyproline contents in the longissimus thoracis et lumborum (LTL) and affected dry matter, protein and hydroxyproline contents (p < 0.05, p < 0.001 and p < 0.01, respectively) in BF muscles, and differences in the colour of muscles were also observed. The shear force in the Warner-Bratzler (WB) test was higher (p < 0.001 and p < 0.01, respectively) for LTL and BF muscles during the first hunting season. The hunting season did not affect the total SFA in the intramuscular fat (IMF) of all the tissues, but it affected levels of monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids in the muscles. No differences were found in the total saturated fatty acids (SFA) of both muscles between the sexes, but females demonstrated lower (p < 0.05 and p < 0.01, respectively) and more favourable n-6/n-3 PUFA ratios in the muscles and fat and a lower (p < 0.05) thrombogenic (TI) index in the LTL compared with males.

PCR-RFLP identification of meat from red deer, sika deer, roe deer, fallow deer, mouflon, wild boar, hare and cattle

Meat authentication is currently a key topic in relation to the quality and safety of food of animal origin at all levels of production and the global distribution chain. New polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP) based on digestion of PCR products with two restriction enzymes, MboII and AciI, have been developed for the specific identification of raw and heat-processed meat from red deer (Cervus elaphus), sika deer (Cervus nippon), roe deer (Capreolus capreolus), fallow deer (Dama dama), mouflon (Ovis musimon), wild boar (Sus scrofa), hare (Lepus europaeus) and cattle (Bos taurus). The PCR primers were targeted in a well-conserved region of the cytochrome b (CYTB) gene to amplify a 378 bp region of all the analysed species. This simple, rapid and cost-effective method is suitable for identification of the meat of game species and their possible substitution by beef.

Determination of mammalian DNA in commercial canine diets with uncommon and limited ingredients

Over‐the‐counter (OTC) limited ingredient canine diets could be reliable alternatives to veterinary therapeutic formulations for the diagnosis and management of adverse food reaction (AFR). However, the possibility of undeclared ingredients jeopardizes the efficacious use of OTC options for medical purposes. The objective was to determine the presence of undeclared ingredients in OTC canine dry diets marketed as limited or single protein source diets. Twenty‐one OTC adult canine diets marketed as limited or single protein source diets were purchased. Multiplex PCR was used to screen for DNA of 10 mammalian species with species‐specific primers that anneal to regions of the mitochondrial cytochrome b gene. The presence of DNA from one or more species not declared on the label was identified in all 21 diets: cow (Bos taurus), pig (Sus scrofa), sheep (Ovis sp.), goat (Capra hircus) and bison (Bison bison). Twenty diets were positive for the declared protein source and one diet was negative for the declared species. Cat (Felis catus), dog (Canis sp.), horse (Equus sp.), mouse (Mus musculus) and rat (Rattus norvegicus) DNA was not identified in any samples. The presence of undeclared mammal species in OTC canine dry diets marketed as having limited or single protein source ingredients may complicate AFR diagnosis and treatment. However, PCR can detect a miniscule amount of DNA which might not be clinically significant, because the amount needed to elicit a response is unknown. Quantification of the contamination was not determined in this study, precluding discrimination of intentional adulteration from unavoidable cross‐contamination.

A quantitative polymerase chain reaction assay for the detection of equine (horse and donkey)-originated meat in processed bovine meat products

Meat is one of the most important basic foodstuffs in human nutrition. Nowadays, adulteration and authenticity are common problems for meat products. Identification of meat species is important in terms of consumer protection and prevention of adulteration. There are different methods to determine adulteration of meat and meat products. These methods are histological controls, serological tests, and quantitative polymerase chain reaction. In this study, species identification and quantification analysis of meat and meat products were done by using horse-, donkey-, and bovine-specific primers with quantitative polymerase chain reaction method. Triple meat mixtures containing horse and donkey meat ranging from 0.1 to 50% levels were prepared within a bovine mixture for using species identification and quantification analysis. The method specificity was confirmed by melting curve analysis. In conclusion, quantitative polymerase chain reaction is an easy, rapid, and reliable method for meat species identification, and with this study an applicable method was developed for the detection and quantification of equine-originated meat in bovine meat products.

Effect of age and gender on carcass traits and meat quality of farmed brown hares

A total of 48 sub-adult hares and adult reproducing farmed hares were used to characterize carcass and meat traits according to the age and gender of animals. With respect to carcass traits, when age increased, the carcass weight significantly increased (2022 to 3391 g; P<0.001), but dressing out percentages did not change. The dissectible fat (1.3% to 2.2%; P<0.05) and Longissimus lumborum (LL) proportions (13.5% to 14.5%; P<0.001) and muscle-to-bone ratio of hind legs (5.11 to 6.23; P<0.001) increased, whereas the hind leg proportions decreased (37.3% to 36.3%; P=0.01). As for the meat quality, the pH of hind leg (5.74 to 5.83; P<0.001) and LL (5.53 to 5.69; P<0.001) increased with age, while the L* index decreased in both cuts (42.9 to 34.4 in hind leg; 45.1 to 40.3 in LL; P<0.001). The redness index increased at the hind leg (4.07 to 5.76; P<0.001), while it decreased at LL (3.03 to 1.46; P<0.001). In the case of the hind leg, meat thawing losses decreased (1.58% to 1.02%), and shear force increased (2.97 to 4.02 kg/g). In the case of LL, thawing losses decreased (8.79% to 4.91%; P<0.001) in the adult hares compared with the sub-adult ones. Meat water and protein contents decreased in the hind leg and LL of the adult hares compared with the sub-adult ones, whereas ether extract increased in a restricted range in LL only (0.92% to 1.11%; P<0.001). In the case of the hind leg, the rate of the saturated fatty acids (SFA) decreased (41.0% to 26.7%), and the rate of the polyunsaturated fatty acids (PUFA) increased (34.0% to 45.3%) (P<0.001). In the case of LL, SFA (38.6% to 42.9%) and monounsaturated fatty acids (19.4% to 27.2%) increased, whereas PUFA decreased (42.0% to 30.1%) when the age increased (P<0.001). Gender affected only the slaughter results and carcass traits. In conclusion, farmed hares have favourable slaughter results (high dressing percentage), carcass traits (high hind legs and loins rates), and meat nutritional value (high-protein, low-fat meat). This fact would offer additional commercial opportunities, in addition to restocking, to hare farmers.

Cross priming amplification with nucleic acid test strip analysis of mutton in meat mixtures

A simple, sensitive, accurate and affordable rapid detection of meat species authentication is urgently needed in food industry. In this study, a cross priming amplification (CPA) combining nucleic acid test strip (CPA-Strip) assay for rapid detection of mutton from meat mixture were developed and its feasibility was investigated. In an isothermal CPA system, cytochrome b (cytb) gene as target was amplified at 63°C for 60min. The nucleic acid strip was able to show the corresponding test line in the presence of target gens in 5min. Non-targeting gene interference was not evident. The CPA-Strip has been applied for the detection of 0.1-100% mutton in a thermal treated meat mixtures with a detection limit of a detect limit of 1%. CPA-Strip assay would be a promising simple, rapid and sensitive method for identification of target species in raw and processed meat mixtures.

Meat Species Identification using Loop-mediated Isothermal Amplification Assay Targeting Species-specific Mitochondrial DNA

Meat source fraud and adulteration scandals have led to consumer demands for accurate meat identification methods. Nucleotide amplification assays have been proposed as an alternative method to protein-based assays for meat identification. In this study, we designed Loop-mediated isothermal amplification (LAMP) assays targeting species-specific mitochondrial DNA to identify and discriminate eight meat species; cattle, pig, horse, goat, sheep, chicken, duck, and turkey. The LAMP primer sets were designed and the target genes were discriminated according to their unique annealing temperature generated by annealing curve analysis. Their unique annealing temperatures were found to be 85.56±0.07℃ for cattle, 84.96±0.08℃ for pig, and 85.99±0.05℃ for horse in the BSE-LAMP set (Bos taurus, Sus scrofa domesticus and Equus caballus); 84.91±0.11℃ for goat and 83.90±0.11℃ for sheep in the CO-LAMP set (Capra hircus and Ovis aries); and 86.31±0.23℃ for chicken, 88.66±0.12℃ for duck, and 84.49±0.08℃ for turkey in the GAM-LAMP set (Gallus gallus, Anas platyrhynchos and Meleagris gallopavo). No cross-reactivity was observed in each set. The limits of detection (LODs) of the LAMP assays in raw and cooked meat were determined from 10 pg/μL to 100 fg/μL levels, and LODs in raw and cooked meat admixtures were determined from 0.01% to 0.0001% levels. The assays were performed within 30 min and showed greater sensitivity than that of the PCR assays. These novel LAMP assays provide a simple, rapid, accurate, and sensitive technology for discrimination of eight meat species.

Detection of rabbit and hare processed material in compound feeds by TaqMan real-time PCR

Food and feed traceability has become a priority for governments due to consumer demand for comprehensive and integrated safety policies. In the present work, a TaqMan real-time PCR assay targeting the mitochondrial 12S rRNA gene was developed for specific detection of rabbit and hare material in animal feeds and pet foods. The technique is based on the use of three species-specific primer/probe detection systems targeting three 12S rRNA gene fragments: one from rabbit species, another one from hare species and a third fragment common to rabbit and hare (62, 102 and 75 bp length, respectively). A nuclear 18S rRNA PCR system, detecting a 77-bp amplicon, was used as positive amplification control. Assay performance and sensitivity were assessed through the analysis of a batch of laboratory-scale feeds treated at 133°C at 3 bar for 20 min to reproduce feed processing conditions dictated by European regulations. Successful detection of highly degraded rabbit and hare material was achieved at the lowest target concentration assayed (0.1%). Furthermore, the method was applied to 96 processed commercial pet food products to determine whether correct labelling had been used at the market level. The reported real-time PCR technique detected the presence of rabbit tissues in 80 of the 96 samples analysed (83.3%), indicating a possible labelling fraud in some pet foods. The real-time PCR method reported may be a useful tool for traceability purposes within the framework of feed control.