Detection of ovine milk adulteration using taqman real-time pcr assay

Food safety, quality and composition have become the subjects of increasing public concern. To prevent fraud and enhance quality assurance, credible analysis of dairy products is crucial. Bovine milk is more widely available and cheaper than milk of sheep and goat. Bovine milk is also processed in large quantities to produce a range of dairy produce. DNA-based methods have proven to be more reliable, because of the stability of DNA under the conditions of high temperature, high pressure, and chemical treatment used during the processing of some food products. The commercial InnuDETECT cheese assay based on the principle TaqMan real-time PCR systems have been tested for the identification and quantification of bovine DNA in ovine milk samples. DNA was extracted using the InnuPREP DNA Mini Kit and quantified by the QuantiFluor dsDNA system. The assay showed good linearity, with correlation coefficient of R2 = 0.983 and efficiency of 86%. The internal control amplified fragment from different mammalian species (cow, sheep and goat), with similar CT values. Detection of bovine DNA in milk mixtures was achieved even in samples containing 0.5% of bovine milk. The InnuDETECT cheese assay has been successfully used to measure bovine DNA in ovine milk, and will prove useful for bovine species identification and quantitative authentication of animal-derived products.

Influence of different curing methods on the fatty acid composition in sausages prepared from red deer meat

These curing agents play a decisive role in obtaining the specific sensory properties, stability and hygienic safety of products such as fermented sausages, ham and, more recently, emulsion type of sausages. The effect of using two different curing agents (sodium chloride and nitrate) on fatty acid compounds in dry-cured deer meat was investigated in our study. The concentration of free fatty acids in the fat depends on the hydrolytic activity of the lipases, the microbial metabolic processes, and the oxidative reactions that work on the free fatty acids released in the lipolysis. The main identified fatty acids in all different types of curing were palmitic acid (16 : 0), oleic acid (c18 : 1 cis-9), stearic acid (C18 : 0). The resulting n-6/n-3 PUFA ratio in the muscle samples of red deer showed no variation in different types of curing and was beneficially low within the range of 3.9 : 1 and 4.49 : 1. Total free fatty acids, whether saturated, monounsaturated or polyunsaturated fatty acids, did not increased (p >0.05) greatly through the processing of dry-cured deer meat. Also there was no effect of curing method on fatty acids composition in two different muscles Semitendinosus muscle (ANOVA, p >0.05, F - 0.003, F crit. - 3.041) and Triceps brachii muscle (ANOVA, p >0.05, F - 0.05, F crit. - 3.01). There were found no significant (p >0.05) differences between fatty acids content in sausages prepared by brining in NaCl and Nitrate salt. The present study revealed that game meat can function as a good source of bioactive compounds that are essential for human nutrition.

Research And Practice: Quantification Of Raw And Heat-Treated Cow Milk in Sheep Milk, Cheese And Bryndza By ELISA Method

The aim of this study was to test the reliability of commercial ELISA tests (RC-bovino) within raw and heat treated cow milk detection in sheep milk and cheese in order to obtain a high-quality, reliable and economically beneficial method suitable for routine application in practice. These tests were subsequently used for quantification of cow milk in commercial "Bryndza". Raw sheep milk, cow milk and heat-treated cow milk (pasteurisation at 72 °C for 15 sec or at 85 °C for 3 sec) were mixed in precisely defined proportions (0 - 100% cow milk in sheep milk). The milk mixtures were sampled to detect adulteration and subsequently cheese was made. By ELISA tests was possible to determine these amounts of raw cow milk in sheep milk: 0.5% (0.2%), 5 % (4.81%), 50% (42.08%) and 75% (56.52%). The pasteurized samples in different combinations gave lower optical density responses than those prepared from raw milk (by approximately 60%). In context with the above mentioned, the relationship between the real and detected amount of cow milk (%) in different production stages (milk, cheese) using a regression analysis was examined. However, a lower reliability of the detection was indicated by R2 values, which ranged from 0.4058 (cheese) to 0.5175 (milk). In practice this means that although individual percentage (%) of cow milk in the sample can be detected, but in the unknown sample it can not be clearly confirm whether the cow milk was raw or heat-treated. In this context, the results can be inaccurate and may not correspond to the real situation. Within monitoring phase of this research, 9 samples of bryndza were analysed with the results of detected cow milk ranged from 11.56% to 14.3%. The obtained results confirm that the appropriate selection of ELISA tests can become an important factor in the setting of analytical capabilities for the detection of milk and cheese adulteration.

CONCENTRATION OF CADMIUM IN MEAT AND SELECTED MEATS PRODUCTS

The cadmium concentrations depend on the environmental conditions and food production methods. The monitoring of cadmium concentration in meat is important for human health. The concentrations of cadmium in meat and meat products collected from central Slovakia, in the central Europe region and from different countries of West Europe were assessed using by AA spectrometer with graphite furnace (PerkinElmer AAnalyst 80, MA, USA). Within starting materials we detected the highest values of cadmium in beef from foreign production (0.1101 ppm), followed by pork from foreign production (0.0901 ppm) in Lovecka salama and pork thigh (0.0523 ppm) in selected ham. In Lovecka salami we were found the highest concentration of cadmium in final samples from foreign starting materials, followed by homogenized samples from foreign starting materials, final samples from domestic starting materials and homogenized samples from domestic starting materials (0.3728, 0.3549, 0.2387, 0.2112 ppm, respectively). The highest concentration of cadmium in selected ham were found in final products from foreign starting materials, homogenized samples from foreign starting materials, final products from domestic starting materials and homogenized samples from domestic starting materials (0.1453, 0.1382,0.0810, 0.0734 ppm, respectively). The obtained results suggested that the concentrations of cadmium are higher in homogenized samples and final products in Lovecka salami and selected ham in comparison with to starting materials. Technological process of meat processing can create a potential source of heavy metals in final products.

Lutein in food supplements available on the markets of the Viszegrad countries

RP-HPLC method with UV-VIS detection was implemented for determination of contents of lutein in food supplements available on the markets in the Czech Republic, Slovakia, Poland, and Hungary. Altogether, 48 samples of food supplements in three dosage forms (22 samples of tablets, 18 samples of soft capsules, and 8 samples of hard capsules) were analysed. The amounts of lutein specified by the producer complied with their real contents only in 7 samples of the food supplements. Lutein in soft capsules showed the highest stability against oxidation; lutein in tablets was more prone to oxidation and lutein in hard capsules was most susceptible to oxidation process. Out of 21 Czech products, only four fell into the category of satisfactory products, three of them were soft capsules and one was a tablet. Out of 27 products manufactured abroad, only three were evaluated as satisfactory products, all of them were soft capsules, out of 48 analysed food supplement samples just seven fell into the category of satisfactory preparations, eight were evaluated as less satisfactory preparations, five were found inadequate products and 28 samples were labelled unsatisfactory. Only one in six analyzed samples contained the amount of lutein specified by the manufacturer, almost 60% of monitored lutein containing food supplement samples fell into the unsatisfactory product category. 

Determining the presence of chicken and turkey meat in selected meat products using realtime PCR method

The one of the most convenient method for the identification of animal species in raw and processed meat products is the examination of DNA sequences. Real-Time PCR are particularly suitable because even small fragments of DNA formed during heat processing of the meat can be amplified and identified. TaqMan Real-Time PCR is a rapid, convenient and sensitive assay for meat identification. For chicken and turkey meat identification we were using species-specific primers and TaqMan probe designed on the mitochondrial cytochrome b. The intensity of the fluorescence signal has risen at a variety of different samples. We analysed sixteen the samples of turkey meat products and we found the incidence of chicken at nine samples in the range of the detection range of the reaction0.1 to 100%.  Sample 8 fluorescence intensity exceeded the detection threshold in the 22.11 cycle (Cp = 22.11); Sample 6, (Cp = 23.19); Sample 1 in 27.08 cycle (Cp = 27.08); Sample 7 in 31,7 cycle (Cp = 31.7) and sample 5 in 32.32 cycle (Cp = 32.32). All Cp values for these samples fluorescence intensity exceeded the detection threshold in earlier cycles as sample the 100% turkey DNA. It follows that in the samples no. 8, 6, 1, 5, and 7 is in the range of chicken DNA detection range of the reaction, from 0.1 to 100%. Sample 11 in the cycle 27,08 (Cp = 27.08); Sample 10 in the cycle 27.8 (Cp = 27.8); sample 16 in 28.03 cycle (Cp = 28.03) and sample 13 in the cycle of 29.18 (Cp = 29.18). In recognition of the results of the monitoring of the content of chicken meat in meat products it is appropriate to further verification and testing detection kits used to work for possible use in practice since it has been found to be sufficient sensitivity and specificity to 30 cycle reaction.

Determination of the species specificity of the primers for the detection of chicken and turkey meat by realtime PCR method

The aim of this work was to use TaqMan Real-Time PCR for quantitative authentication of chicken and turkey meat.To meet this purpose, a specific pair of primers and TaqMan probe was used. The test was aimed at identifying the reaction cycle of turkey and chicken meat using by two sets of primers. With first set of primer designed for chicken we obtained the following results: Cp = 16.18 for 100% chicken DNA Cp = 29, 18 100% turkey DNA It was also amplified DNA of pig that exceeded the detection threshold fluorescence intensities in the 31.07 cycle (Cp = 31.07). Using primers designed for turkey we obtained the following results Cp = 31.16 for 100% CHDNA, Cp =16.18 100% TDNA. It was also amplified the 100% DNA of rabbit in 31.63 cycle (Cp = 31.63) and deer in cycle 32 (Cp = 32). The DNA of all other animal species was amplificated after more than 35 cycles (Cp >35). It follows that the second detection primer pair is specific enough to unrelated species of animals by 30 cycles of the reaction. Species authentication based on DNA analysis from this perspective overcomes all the shortcomings of proteins. At present, DNA analysis use different types of PCR. Is the most progressive Real-time PCR, which is suitable for the specific use of detection (primers and TaqMan probe). The TaqMan Real-time PCR is within the sensitivity and specificity, clearly one of the best methods for identifying the species of chicken and turkey meat. The specificity of this method, however, depends primarily on the specificity of the primers and TaqMan probe. The 30 cycle reaction was chosen by us as the threshold for specificity using primers for authentication chicken and turkey meat.

Detection of Lupine (Lupinus spp. L.) as a food allergen using three methods: end-point PCR, Real-Time PCR and Elisa

The aim of this work was to compare three methods for the detection and quantification of lupine as an allergen in food. The methods that were used in this work were the direct method: ELISA and the indirect methods: end-point PCR and real-time PCR. We examined the detection limit (the sensitivity with which we can detect the presence of the allergen in a sample) and the reliability for performing an analysis. We used 17 samples of plant species from a processing plant for dehydrated soups production and lupine samples from lupine processing companies. Its practical use is wide and it is used mainly in the bakery industry, in the manufacture of confectionery, pasta, sauces, as a substitute for soy and also in the production of gluten-free food, because it does not contain gluten. Lupine, however, is also included in the list of 14 allergenic substances, which in accordance with the EU legislation must be listed on food labels. The high risk group, which suffers from primary sensitization or cross-reaction with peanuts, are allergic patients. In the EU, people who are allergic to peanuts range from 0.7 to 1.5%. In experiment 1, we detected the presence of lupine using primers for the detection of α- and δ-conglutine in the samples, using the end-point PCR method and the detection limit of this reaction was at the level of 100 ppm. For the vizualization of the DNA fragments, we used a 2% agarose gel and UV visualizer. In experiment 2 we detected lupine using the TaqMan real-time PCR reaction and primers for the detection of α and δ-conglutine at the level of 10 ppm of lupine in sample. The CP values of lupine using primers for the detection of α-conglutine was 24.85 ± 0.12 and the reliability equation was R2 = 0.9767. The CP lupine values using primers for the detection of δ-conglutine was 22.52 ± 0.17 and the reliability equation was R2 = 0.9925. In experiment 3, we used a sandwich ELISA method for the detection of lupine and the detection limit was within the range of 2-30 ppm and the reliability of the method according to the reliability equation was R2 = 0.9975. The high sensitivity and equation of reliability justify the use of these methods for the detection and quantification of lupine in practice. The most sensitive indirect method for the detection of lupine in our study was the method of real-time TaqMan PCR with a detection limit  10 000-10 ppm of lupine. The most sensitive direct methot was ELISA with detection limit 2-30 ppm of lupine.

Lead concentration in meat an meat products of different origin

Meat is very rich and convenient source of nutrients including also a large extent of microelements. Contamination with heavy metals is a serious threat because of their toxicity, bioaccumulation and biomagnifications in the food chain. The lead concentrations depend on the environmental conditions and the food production methods. Ingestion of contaminants, especially heavy metals, by animals causes deposition of residues in meat. The aim of this study was to determine the levels of lead in the Malokarpatska and Lovecka salami during the technological processing with comparison to the raw materials originating from domestic and foreign production. Lead content was determined by atomic absorption spectrometry. The starting materials in the Malokarpatska salami were found to contain the highest level of lead in the beef of foreign production (7.58 ppb), followed pork from foreign production (3.43 ppb), beef from domestic production (3.27 ppb), pork bacon from foreign production (2.41 ppb), pork from domestic production (1.63 ppb) and pork bacon from domestic production (1.57 ppb). The average concentration of lead was higher in homogenized samples with addition of additives and spices and ranged between 6.49 to 7.56 ppb. The lead concentration in final product Malokarpatska salami was in the range from 8.57 to 8.89 ppb. The highest mean Pb concentrations in the Lovecka salami in the starting materials were beef from foreign production, beef from domestic production, pork from foreign production, pork bacon from foreign production, pork from domestic production and pork bacon from domestic production (7.31, 3.77, 3.21, 2.40, 2.03, 1.97 ppb, respectively). Increasing concentration of lead was found after the addition of additives, spices and curing compounds causing a threefold increase in the concentration of lead in final products Lovecka and Malokarpatska salami. Technological process of meat processing can create a potential source of heavy metals in final products. Improvements in the food production and processing technology are increasing the chances of food contamination with various environmental pollutants, especially heavy metals.

Genetic diversity and relatedness among seven red deer (Cervus elaphus) populations

Deer (Cervidae) recently belongs to the most important species. The aim of presenting study was evaluation of genetic diversity and relationship within and among seven red deer populations from different origins - Czech Republic, Hungary, hybrids Hungary x New Zealand, Lithuania, New Zealand, Poland and Slovak Republic. This study was conducted to determine the levels of genetic variability and relationships among deer populations from a total of 637 animals originating from seven countries Czech Republic (50), Hungary (35), Hungary x New Zealand hybrids (67), Lithuania (26), New Zealand (82), Poland (347) and Slovak Republic (30).  We used the hair bulbs as a source of DNA.  In total, 213 alleles were observed from the 10 loci surveyed. The number of alleles per locus ranged from 11 (IOBT965) to 35 (T156, RT13). Genetic diversity and relatedness among red deer populations has been performed on a total of 637 animals. A panel of 10 microsatellite markers used in deer were optimized. On the basis of this panel of microsatellites we were investigated genetic variability and relationships by using statistical and graphical programmes. We evaluated how close populations are to each other and their genetic admixture. Molecular genetic data combined with evaluation in statistical programmes could lead to a complex view of populations. 

Xenobiotics and biogenic elements in raw cow's milk

This paper presents the concentration some toxic and biogenic elements in milk from Nitra region. The aim of this investigation was to evaluate 30 samples of raw milk with fat contents 3.8% obtained from milk machine in the Nitra region. Samples were analyzed for metal contents using atomic absorption spectrophotometry (AAS). In comparison with maximum acceptable concentration for milk in the food codex of the Slovak republic, the level of contamination with cadmium was exceeded and reached the value 0.221 µg.ml-1. The copper content ranged from 1.201 µg.ml-1 to 5.810 µg.ml-1 and the average concentration reached 3.793 µg.ml-1.  Iron had an average of 1.824 µg.ml-1. Overall in all milk samples high correlations were found. Between positive correlation (0.7019) and negative correlation between of nickel and potassium concentration in raw milk (-0.72) was found.

Nutirtion labelling of food and allergen in food

The new regulation introduced mandatory nutrition labelling and ordering food manufacturers provide information on energy and six nutrients: fat, saturated fatty acids, carbohydrates, sugars, protein and salt - in that order, and per 100 g or 100 ml. This information should be included in the nutritional table in one visual field (usually on the back cover), moreover, can also be expressed on per serving. It is important to realize that this regulation requires manufacturers indicate the nutritional value in one field of vision, usually on the "back cover" designation in the principal field (e.g. "on the front cover") remains voluntary. Food allergy is a significant public health issue worldwide. Regulatory risk management strategies for allergic consumers have focused on providing information about the presence of food allergens through label declarations. A number of countries and regulatory bodies have recognized the importance of providing this information by enacting laws, regulations or standards for food allergen labelling of ‘‘priority allergens. Increasing volume of the international food trade suggests that there would be value in supporting sensitive consumers by harmonizing (to the extent possible) these regulatory frameworks. As a first step toward this goal, an inventory of allergen labelling regulations was assembled and analyzed to identify commonalities, differences, and future needs.

Quantitative and structural changes of testis and semen quality parameters changes caused by peroral administration of diazinon in rats

The aim of this study was to find the quantitative and structural changes in the rat testis and changes of semen quality after a diazinon administration. METHODS: Rats received diazinon (99% purity) in thier drinking water (40 mg.l-1) with free access. Age of rats at the beginning of the experiment was 30 days and experiment lasted for next 90 days. The histological samples were evaluated by histological and morphometric methods in light microscopy and the samples of semen were evaluated with CASA method. RESULTS: Disintergation of cellular associations in the seminiferous epithelium, germ cells evacuation into the tubule lumen and thier necrosis were mostly observed. Rarely vacuolisation and cracks of epithelium and fibrotisation of interstitial tissue were noted. Morphometric methods have shown extension of epithelium (P<0,01), reduction of  tubule lumen (P<0,001) and dilatation of blood vessels (P<0,001). In CASA analysis elevation of all parameters were noted, with statistically significant increase of DSL, VSL, ALH. Dilatation of blood vessels will be probably one of the most significant finding in diazinon toxicity because changes in blood flow in the testis are the key factors of accurate physiological function of testis. The epithelium despite the serious disintegration of germ cells associations and release of these necrotised germ cells to the lumen was significantly extended. This fact indicates the self-reparation compensational function. The same tendency (stimulation effects) has been found in all analysed sperm parameters. It supports previous hypothesis. CONCLUSIONS: Diazinon in this design of experiment causes the disintegration of the germinal epithelium cells associations consequently leading to necrosis and release of these cells to the tubule lumen. Dilatation of blood vessels and unknown stimulation effect on sperm quality parameters are two other common effects of diazinon. We concluded that diazinon in our subchronic low dose test causes middle to moderate histological,  morphometric and semen quality changes which were partially compensated with some unknown recovery mechanism. Otherwise, subcellular structures and their functions may be damaged which can lead to subfertility. Further investigation of diazinon is needed for verification of our hypothesis.

The yield of dna in thermal terated deer meat

Residuals of DNA are one of the most important factors for detection, traceability and reverse authentication of deer meat. In this project we isolated DNA from deer processed meat and analysed by electrophoresis. Goal of the study was compute ratio between raw meat and several heat processed deer meat. Samples were prepared by five heat treatment techniques (pan roasted with temperature 180-240°C, fried with 156°C, braised with temperature 100-150°C, boiled in 100.2°C water and autoclaved in different time intervals). The highest amount of residual DNA 1927ng was obtained with two hours boiled sample. The lowest value 89.89ng was obtained with one hour braised sample. In technological adjustments highest amount of DNA and 1927ng, so the total yield of 192.7ng.-l was observed in the sample we cooked for two hours at boiling temperature. 

Optimalisation of species identification of common carp (Cyprinus carpio) using SYBR® green I real-time PCRmethod

European Union Member States, together with a number of countries around the world, places great emphasis on ensuring the protection of consumers as a potential food allergic from food allergies. to inform consumers that their product may contain any of the risk of allergenic ingredients. For species identification of fish and fish products as a potential food allergens are used by many analytical methods as well as their authentication. We are in our work applied the method of SYBR® Green I. Real-Time PCR. We focused on pre-designed molecular - genetic marker of common carp (Cyprinus carpio), which comes from the mtDNA control D - loop area. We analyzed its presence in DNA isolates from the 5 kinds of freshwater fish, diluted to 10 % concentration. Results of using the optimized SYBR ® Green I Real-Time PCR method for species identification common carp (Cyprinus carpio) indicate to its suitability.

Nutrigenomic analysis of C677T mutation of MTHFR gene in Slovak population

Total of 124 individuals originated from Slovak Republic has been nutrignomically analysed. Analysis was focused to mutation C677T of MTHFR gene detection and analysis of mutant genotypes frequency. Observed frequency of allele 677C was 0.6998 and allelic frequency of mutant variant 677T was 0.3992. Genotype frequency of mutant heterozygotes with 71% activity of MTHFR enzyme was 0,391 and mutant homozygotes with 33% MTHFR enzyme activity was 0.153. Result shows 64% of Slovak has decreased activity of enzyme MTHFR, and 14.3% of Slovak has predisposition to cancer, cardio vascular diseases, loss of fertility and many others complications according to improper nutrition, low folic acid and B12 vitamin intake. 

Microbial biofilms produced by pseudomonas fluorescens on solid surfaces

A biofilm is a complex aggregation of microorganisms growing on a solid substrate. Biofilms are characterized by structural heterogeneity, genetic diversity, complex community interactions, and an extracellular matrix of polymeric substances. The experimental part was focused on the adhesion of bacterial cells under static conditions and testing the effectiveness of disinfectants on created biofilm. In laboratory conditions we prepared and formed the bacterial biofilms Pseudomonas fluorescens in the four test surfaces of stainless steel, glass and plastic materials - PE (polyethylene) and EPDM (ethylene propylene diene monomer). Over the next 72 hours and 72 hours were observed numbers of adhesion bacterial cells of P. fluorescens on solid surfaces of tested materials. The highest values adhesion cells reached P. fluorescens cells after 72 hours of cultivation on plastic surfaces, where  was increased in adhesion bacterial cells for EPDM in the values of 105 CFU/cm2 and for PE up to 106 CFU/cm2. The subsequent repeated 72-hour cultivation P. fluorescens was an increase (growth) in the number of adhesion bacterial cells to all tested surfaces.

Methods for fish species identification in food products

The need for identification of fishery products in food is currently ongoing issue for both consumers and producers of food. Consumer interest is driven in one the healthy diet, which prefers fish products, as an indispensable ingredient food and on the other hand, is a potential allergen causing health problems in humans allergic to fish protein. Allergy is a phenomenon that significantly affects human health, as well as overall life expectancy of an individual. The large number of fish species are known to trigger allergic reactions directly food intake or inhalation of fumes only, depending on the sensitivity orgamizmu. Large quantity of fish allergens are proteins from the stock protein to enzymes. Methods used for species identifications of fish in food products are PCR sequencing, multiplex PCR, PCR-RFLP, PCR-SSCP, RAPD, real-time PCR.