Application of antimicrobial chitosan-Furcellaran-hydrolysate gelatin edible coatings enriched with bioactive peptides in shelf-life extension of pork loin stored at 4 and -20 °C

In this study, the authors investigate the preservative capabilities of edible coatings comprising a blend of chitosan, furcellaran and gelatin hydrolysate enhanced with the bioactive peptides RW4 and LL37. The preservative effects on pork samples stored for 21 days at 4 °C and 6 months at -20 °C were studied, while examining changes in microbiological contamination, pH levels, water activity and sensory attributes. Microbiological analyses reveal the coatings' antimicrobial efficacy against aerobic bacteria, microscopic fungi and yeasts, particularly during the initial storage period, when coated samples exhibit microbial reductions of 0.5-2 log CFU/g compared to the controls. The coatings have no discernible impact on water activity during storage in refrigerated or freezer conditions. Notably, differences in pH development can be observed between the coated and control samples, potentially attributable to the antimicrobial action of the coatings. Sensory analysis allows to highlight the inhibition of deterioration related to sensory attributes through the use of edible coatings. In conclusion, employing bioactive peptide-enriched edible coatings holds promise for extending the shelf-life of perishable foods.

Effect of Bear Garlic Addition on the Chemical Composition, Microbiological Quality, Antioxidant Capacity, and Degree of Proteolysis in Soft Rennet Cheeses Produced from Milk of Polish Red and Polish Holstein-Friesian Cows

This study aimed to assess the effect of milk source and bear garlic addition on the selected properties of soft rennet cheese. Cheeses were produced from cow milk derived from two sources: Polish Red cows (PR) and Polish Holstein-Friesian cows (PHF) with a 0.5% (w/w) addition of bear garlic (Allium ursinum L.) dried leaves. Chemical composition and fatty acid profiles (GC) were determined in fresh cheeses. Fresh and stored for two weeks cheeses were subjected to microbiological studies, i.e., total aerobic bacteria count (TABC); count of Lactococcus sp., yeast and molds; coliforms; analysis of the proteolysis extension by means of o-phthaldialdehyde (OPA) assay and free amino acids content (HPLC); antioxidant capacity as 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and ferric reducing antioxidant power (FRAP); as well as pH and water activity. Cheeses with bear garlic herbs were more prone to proteolysis but this was not accompanied by any effect on the microbial counts, water activity or pH. Cheeses produced from PR milk contained less monounsaturated fatty acids (MUFA) but were richer in n-3 PUFA and had a lower n-6/n-3 FA ratio than cheeses from PHF milk. Bear garlic addition increased DPPH anti-radical power but had less of an effect on the FRAP values.

OPTIMIZATION AND VALIDATION OF HPLC-FLD METHOD FOR DETERMINATION OF AFLATOXIN B1 AND PRODUCTION OF THIS MYCOTOXIN BY ASPERGILLUS SECTION FLAVI ISOLATES

A high performance liquid chromatography coupled with fluorescence detection (HPLC-FLD) was evaluated for the monitoring of aflatoxin B1 (AFB1) production by Aspergillus section Flavi isolates, which were found in the commodities of Slovak origin (barley and tomatoes). Rapid validation of the method was performed and the method was applied for the determination of the mycotoxin. Based on the calculated validation characteristics, the method showed high sensitivity and reproducibility. The LOD and LOQ determined were 0.03 and 0.10 µg.mL-1 which is fully acceptable for the determination of the AFB1 in isolates from plant commodities. The calibration graph was linear in the concentration range of 0.01– 10.0 µg.mL-1. The optimized method was used for the analysis of the mycotoxin in three Aspergillus section Flavi isolates. The submerse cultivation was performed at 25±1°C in yeast extract sucrose liquid medium and material was collected on the 7th, 14th and 21st day of cultivation.  Simple sample extraction was carried out with use of ethyl acetate, and measurement was done with use of the mobile phase consisting of water and methanol by HPLC-FLD. Production of the AFB1 by isolates was ranging from <LOD (0.03 µg. mL-1) to 49.38 µg.mL-1 with the highest concentration on the 14th day of cultivation. The maximum level of AFB1 was achieved by the Isolate 1 (isolated from barley, Kolíňany, 2018).

CURRENT OVERVIEW IN THE FIELD OF APPLICATION OF EDIBLE COATINGS/FILMS (MEAT PRODUCTS EXAMPLES)

Preservation and storage of food is an integral part of the food industry. There is currently a progress in the field of preservation and storage technologies, which reflects the demands made by consumers. Active and intelligent packaging is an innovative technique that offers a wide range of possibilities for improving the quality of the food. In accordance with the green policy and the demands of consumers for the minimum addition of chemical additives to food, there is an open space for the application of edible coatings/films as packaging materials for food. Edible coatings/films due to their natural character are able to act as carriers of wide range of bioactive substances, dyes, nutraceuticals, which can extend the shelf life of food and, at the same time, preserve or improve the quality of food. From these substances, the focus is on phytochemicals, nanoparticles, probiotics, protein hydrolysates or bioactive peptides and others from wide range of sources. The possible incorporation of bioactive peptides with a wide range of bioactive effects is a current topic that attracts the attention of researchers.

The Effect of Heat Treatment on Cow's Milk Protein Profiles

Milk is a food of high nutritional value processed by heat treatment. Heat treatment of milk is a technological process designed to inhibit the growth of microorganisms and extend the shelf life of products. The heating process directly affects the molecular structure of whey proteins by the process of denaturation. It leads to the formation of a whey protein−casein polymer complex. Based on these facts, milk heat-treatment conditions should be controlled during milk processing. This work focuses on describing the whey protein denaturation process and formation of the complex of whey protein with casein. The effect of heat treatment on individual milk protein fractions alpha-casein (α-cas), beta-casein (β-cas), kappa-casein (κ-cas), beta-lactoglobulin (β-lg) and alpha-lactalbumin (α-la) was studied by SDS-PAGE. Formation of the whey protein−casein polymer complex increased significantly (p < 0.05) on increasing the temperature and duration of the heat treatment.

Evaluation of nutritional composition and sensory properties of cheese, cheese spreads and traditional butter from Slovak production

Cheese production is associated with the analysis of its nutritional composition as well as with the sensory evaluation of the acceptance of the products. The paper is aimed at the determination of basic chemical parameters such as the content of proteins, fat, dry matter, salt and, pH and also on the evaluation of sensory properties of hard cheeses by the sensory panel. The GC-MS analysis of cheeses, cheese spreads, and traditional butter was performed to evaluate the aroma profile of the dairy products analyzed. The dry matter in the analyzed cheeses varied between 56.75 and 71.83%, the fat content varied from 18.73 to 30.83%, and the salt from 1.21 to 2.61%. The presence of proteins was found between 27.76 and 32.61% and the pH of the cheeses ranged from 5.21 to 6.01. The results of the sensory analysis were processed using a PCA map. The results showed that sample no. 5 was rated within all attributes as the best. Sample 3, 2, and 1 followed. Sample 4 received the lowest score. The volatile aromatic compounds that contribute to a taste perception were analyzed by GC-MS in dairy products. The aroma profile was built by the volatile compounds that belonged to chemical families of alcohols, aldehydes, ketones, esters, amides, amines, imines, and terpenes. In particular, cheeses contained mostly alcohols (3-methyl-1-butanol), aldehydes (3-methylbutanal and benzaldehyde), and ketones (acetoin, 2,3,3-trimethylcyclobutanone, 2-heptanone, 2,3-butanedione, acetone, 2-butanone, 2-nonanone, 2- pentanone).  The spreads most often contained alcohols (represented by 2-methyl-1-butanol, 3-methyl-1-butanol and cyclopropane-1,2,3-d3-methanol), aldehydes (2-methylbutanal, 3-methylbutanal, benzaldehyde) and ketones (acetoin, 2-heptanone, 2-pentanone, 2-butanone and 2,3-butanedione).

Food adulteration and safety regarding detected market cases and consumer opinions

Food fraud is one of the long-standing causes of scandals attracting particular attention for a long time. This study aimed to monitor food fraud in the European Union and to identify the relationships among the countries where the cases were reported, adulterated commodities (seafood, eggs, milk, meat, fish, and their products) and types of fraud. The secondary data were covered by the survey focused on consumer knowledge about fraudulent activities, ingredient substitution, masking of origin, mislabeling, placing on the market of foods not fit for human consumption within Slovak inhabitants. Primary and secondary data were used to achieve this aim. Primary data were obtained from the Food Fraud and Quality Knowledge Center (KCFFQ) and secondary data from the questionnaire survey from 354 respondents. During the period from 2017 to 2019, 163 cases of food fraud were reported, most of which originated from Italy and mainly concerned fish and fish products. Based on primary data and one-way ANOVA statistical tests, we confirmed five hypotheses. There was found no statistical impact of the country on the type of food fraud (p = 0.0067), but the significant effect was determined on which food was adulterated (p = 0.000001). There was no statistical correlation among years and countries where the cases were reported (p = 0.110), but the statistically significant correlation was confirmed among years and commodities (p = 0.0043) and types of fraud reported (p = 0.009). Based on the processed secondary data from the questionnaire, we can conclude some information or public interest in food fraud problems.

Effect of commercial yogurt starter cultures on fermentation process, texture and sensoric parameters of white yogurt

In this work, we have compared and described the fermentation process of two commercial yogurt starter cultures during the white yogurt production. We used freeze-dried thermophilic starter culture YoFlex® YF - L812 and deep-frozen starter culture Delvo® Fresh YS – 241 for the production of white yogurts. We analysed titration acidity, active acidity, total viable counts, texture, and sensory parameters of white yogurts produced in laboratory conditions. This research was performed for dairy company Mliekareň Kopanice Selce, s.r.o., Slovakia. We did not found statistically significant differences (p >0.05) in titration acidity of both yogurts after 7 hours of fermentation. We did not found statistically significant differences (p >0.05) in the pH of both yogurts after 7 hours of fermentation. We found statistically significant differences (p <0.05) in all textural parameters (hardness, consistency, cohesion, and viscosity). The total viable count of microorganisms in yogurts after 24 hours of fermentation was 6.28 x 107 and 7.14 x 107 respectively.

Effect of preservatives on the shelf-life and sensory characteristics of pasteurized liquid whole egg stored at 4°C

The study focused on the effects of traditional (benzoate-sorbate and triphosphates) and alternative (nisin, Laktocid, Defence JB, and Galimax Flavor) food preservatives on the microbiological quality and sensory properties of pasteurized liquid whole eggs (LWE). The LWE samples with the addition of a test preservative and a control were stored at 4°C for 45 D. The selected microbiological parameters, sensory attributes, and color space parameters were determined. The results were statistically analyzed by means of factorial ANOVA, followed by the Tukey post hoc test. The multivariate method of principal component analysis based on the correlation matrix was employed to assess the relationships between pH and sensory characteristics of LWE. Total plate counts at the end of storage differed significantly, being the lowest in samples with benzoate-sorbate (1.69 ± 0.12 log cfu.g-1) and Laktocid (2.12 ± 0.12 log cfu.g-1). The final counts of lactic acid bacteria on day 45 were lower in the samples with benzoate-sorbate, triphosphates, nisin, and Laktocid (maximum 1.01 ± 1.44 log cfu.g-1). The amounts of yeasts at the end of storage did not differ among samples with different preservatives; none were detected in any samples with the exception of Defence JB (1.28 ± 1.90 log cfu.g-1). The lowest final mold count was observed in LWE with Laktocid (0.92 ± 1.29 log cfu.g-1). In conclusion, Laktocid showed great potential as a preservative; it had however a negative impact on pH value and the sensory properties of LWE.

Authentication and preference mapping of ham

Effective connection between the food industry and consumer demands are specific needs of consumers whitch were monitored in this study by using a preferential mapping method. Preference mapping is based on Principal Component Analysis (PCA), which is performed on preferences ratings given for each product and preferences of each consumer through an online questionnaire. Key features for the consumer choice were colour, odour, consistency, total flavour and overall appearance. We verified the composition and mapped the preferences of 10 hams purchased in Slovakia. In view of the persistence of identified cases of food counterfeiting and meat fraud, intensive monitoring and scrutiny is required through effective and accurate analytical methods, which are crucial for maintaining consumer confidence and ensuring compliance with local legislation and labeling. The reference approach for identifying animal species in food is the PCR method, which is however limited to several animal species, meat types. The use of microarray technology enables the identification of a wider range of animal species and greater user comfort, especially the speed of obtaining the results. It allows 24 animal species to be identified in one analysis in 8 samples at a time. Detection was performed using Chipron LCD Aarray Kit Meat 5.0. In all analyzed samples, components of animal origin were identified in accordance on the packaging of the products. The Meat 5.0 LCD chip, which was used for analysis, has detected the presence of other animal species.

Authentication of poultry products at the breed level using genetic markers

The Oravka tawny is a Slovak national breed of chicken. This breed has combined utility, which means it is valuable for both its meat and eggs. The Oravka tawny is linked to a specific region, Orava, and therefore these products could be protected by European geographical indication. The labeling and sale of chicken meat by the traditional breed of origin are widely used to promote quality and attract those products in the marketplace. For that use, we created the system and method of authentication that can reliably distinguish between the Oravka tawny, other chicken breeds, and other of Oravka”™s colorful characters. In our research, we analyzed 153 chicken feathers from the Oravka breed as well as from breeds used in the process of breeding the Oravka to their current state. They were divided into nine populations. To separate those populations, we used seven microsatellite markers recommended by FAO (Food and Agriculture Organization) and other authors. To create separate clusters of individual breeds, we used DAPC (discriminant analysis of principal components) analysis.

Characteristics of textural and sensory properties of Oštiepok cheese

Oštiepok is a traditional half-fat semi-hard cheese made in Slovakia. The basic raw material used to produce oštiepok cheese is ewe's milk, a mixture of ewe's and cow's milk or cow's milk. Oštiepok cheese is produced either directly at a small-scale mountainside sheep farm, using the traditional on-farm method of production, or at dairies, using the industrial method. Oštiepok cheese was produced as far back as the beginning of the 18th century. An industrial production of Oštiepok cheese using cow's milk were laid by the Galbavý family in Detva (Slovakia) in 1921. The cheese is originally made by cutting off fresh sweet cheese, which is pressed into a wooden, hand-cut and decorated round shape where it is left to stand. Subsequently, it is removed and immersed in warm salty water, left to stand there until the salt penetrates completely in. Then it is necessary that it pass slightly. In its salty water, the ostrich produces its traditional durability, its surface is slightly peeled, mostly yellowish. This cheese may or may not be steamed and may be smoked or unsmoked. Slovenský oštiepok is a protected trade name under the EU's protected geographical indication. A similar cheese is made in the Polish Tatra Mountains under the name Oscypek. The cheeses differ in ingredients' ratios, cheesemaking process and the characteristics of the final products. In this study we have characterized textural and sensory properties of the Oštiepok cheese produced in Slovakia made from ewe's milk, a mixture of ewe's and cow's milk and cow's milk.

Consumers´ awareness of food safety

Eating food is one of the most important needs of every person, so their safety and quality should be crucial for everyone. People expect, that food they eat is hygienically and health safe. Unfortunately, people usually start to focus on food safety only when various food scandals are exposed and it is too late. Mass consumption of food is the cause of a high risk to human health, but only in the case of harmful food. Food-borne diseases are a common and widespread phenomenon in all parts of the world, regardless of the economic development of the country. Protection of human, animal and plant health is one of the main economic priorities of each country. The political objective of the European Union is therefore to ensure that European Union citizens have access to safe and nutritious foods, so it must meet strict safety standards. In ensuring food safety, it is necessary to take into account all aspects of the food production chain as a whole, because each subject can have a potential impact on food safety. This paper deals with the issues of food safety and food quality. The main objective was to find out how consumers perceive higher quality food and whether they read information included on the food packaging. Primary data were obtained from a survey that was conducted on the sample of 478 respondents living in Slovakia. For a deeper analysis, several assumptions, which were verified by Friedman Test, Chi-Square Test of Independence, Wilcoxon Signed-Rank Test, were formulated. The survey has found out that 84% of respondents buy higher quality food and 60% purchase them because of health-related reasons. More than half of respondents search for the information about food safety on the Internet and the same percentage considere government as the most reliable source of information about food safety. Unfortunately, just more than one quarter of them read the information on food label and for 34% is this information unsufficient.

Food safety from a consumers´ point of view: food quality

Food safety is a topic that is currently very much and often discussed. This may be a debate among political representatives, representatives of the food industry, but also among consumers, ie. general public. The issue of food safety and quality is very important in view of the growing globalization of economy, whose mission is to encourage food businesses to improve the production process as a whole and competitiveness. As in every sector, the food market faces many problems arising from market opening, business environment diversity or non-compliance with legislative requirements. The effects of these market imperfections are ultimately borne by the consumer. It is, therefore, appropriate to ensure that consumers are adequately informed about the food they consume. Food production is carried out according to European and world standards. A Slovak customer purchases food imported from abroad. This fact can be caused by the pricing of individual foods but also by the lack of Slovak producers. Foreign competition liquidates the quality Slovak producers. The principle of customers should be to support the economy of the state and to buy domestic food. The submitted document deals with issues of food safety, control and quality of food. The aim of the work was to examine the attitudes of consumers to food safety based on the acquired knowledge and research results, to identify their interest in food safety. It also involved identifying global food safety issues and analyzing consumers' views on the problem under consideration and its impact on their purchasing behavior. Primary data was obtained from a survey that was performed on a sample of 478 respondents. Based on the survey, it was confirmed that 85% of respondents perceive the different quality of the food sold on the Slovak market. Nearly two-thirds of the respondents said they were paying attention to the quality of the groceries. More than half of respondents expressed satisfaction with hygienic sales conditions. Almost 80% think that high-quality food is commonly available. Statistical testing has confirmed the significantly lower quality of food produced abroad. Other assumptions were formulated for more detailed analysis and their relationships were verified by using the statistical methods (Friedman Test, Chi-Square Test of Independence, Wilcoxon Signed-Rank Test).

Food safety from consumer perspective: health safety

Food industry along with agriculture constitute a major economy sector in most countries, because in addition to water intake and oxygen availability, food is another basic determinant for functioning of the human organism. For the proper functioning of human body, it is imperative that the customer chooses food so that the daily diet includes all the necessary nutrients in a reasonable proportion. At present, however, it is becoming more and more common that foodstuffs do not meet strict standards, are not properly stored, the packaging is damaged, or hygiene standards are not being adhered to, and therefore, in addition to health benefiting substances, they also contain harmful ones. According to the World Health Organization, the death of up to 2 million people a year around the world is caused by foods harmful to human health. The main objective of this report was to assess how consumers perceive the health safety of food in Slovakia and to find out whether some types of food are considered as potentially harmful to health. Primary data were obtained through a questionnaire survey conducted from October to December 2017 on a sample of 478 respondents. Respondents answered to 12 factual, and 9 classification questions, which were consequently analyzed using the Friedman test, Nemenyi test and Chi-Square test of Independence. Survey results showed that the majority of respondents had concerns about the health harming effects of food only occasionally and they trust the hygienic level of the restaurant facilities (60.5%), fast food (53%) and frozen food (49.2%) with few reservations. As the most hazardous foods are considered poultry meat, eggs and mayonnaise. If the consumer's health is endangered by food, the guilty party should be punished by ban (61.9%) or by suspension (19.5%).

Content of endogenous sulfur dioxide in wines

Content of free and total endogenous sulfur dioxide were evaluated by classical iodometric titration in must, during winemaking processes and in bio-wine. No exogenous sulfur dioxide was added in any technological operations to simplify the evaluations. In addition, the results were corrected on the content of reductons (total content of reducing substances). The results confirmed formation of endogenous sulfur dioxide from sulfur containing substances (sulfur containing amino acids etc.) in both experiments. Microbial sulfur dioxide is preferably bound to carbonyl substances. Only minor part is present in the free (active) form of the sulfur dioxide. In addition, total content of polyphenols (TPC) and total antioxidant capacity (TAC) were determined by spectrophotometry at the same time. A procedure OIV-MA-AS323-O4B: R 2009 was used. Contents of "free" and "total" sulfur dioxide (with/without correction on contents of reductons) and total content of reductones were determined after complexing the sulfur dioxide with formaldehyde. A standard spectrophotometric method using Folin-Ciocalteu reagent was applied for determination of total content of polyphenolics (TPC) at 765 nm after 60 min incubation. The results were expressed as tannin equivalents (in mg.L-1). A standard DPPH (2,2´-difenyl-1-picrylhydrazyl dissolved in methanol) spectrophotometric method was applied for determination of total antioxidant capacity (TAC) at 515 nm. Depletion of the color intensity was measured after 60 min incubation against blank (methanol) and absorbance decrease Δ(A) = (A0 - A1)/A0 was calculated and used for construction of calibration curve. The TAC values were expressed as ascorbic acid concentrations (in mg.L-1).

The effect of UV-C irradiation on grape juice turbidity, sensoric properties and microbial count

In this work, we investigated the effect of UV-C radiation (254 nm) on turbidity, microbial count and sensoric properties of the grape juices treated or not treated with sulphur dioxide. The UV-C radiation is considered to be germicidal against microorganisms. This technology is routinely used to treat drinking water. Application of this method for the purpose of treating the wine was tested in few studies. These studies have shown a positive effect on the inactivation of microorganisms, but they not dealt in detail with the sensory properties of grape juice after the treatment. The main idea of using this method appears to eliminate the sulphur dioxide from wine making technology. There are people who have a genuine allergy to sulfites, and these allergies are often linked with asthma. These people have an rapid onset of symptoms when drinking liquids like wine treated with sulphur dioxide. In our work we have found that the application of this method of treating the grape juice is problematic. Intensity of UV-C radiation increases the turbidity of grape juices. This effect was observed in all grape juices with or without addition of sulphur dioxide and also in clarified or not clarified grape juices. We found that UV-C radiation negatively affect the sensory properties of grape juices. This effect was more pronounced in grape juices treated with SO2. The smell and taste were significantly negatively changed. Exposure of grape juice treated with sulphur dioxide to UV-C radiation can probably lead to arising the sulphur compounds, which affects the smell and taste of grape juices. Also, it is very likely that the negative change in taste and smell may affect the quality of produced wines. For this purpose, we do not recommend to use UV-C treatment for the grape juice treatment. It will be interesting to conduct a detailed analysis of the grape juices composition before and after UV-C radiation treatment.

Effect of thermal treatment on rutin content in selected buckwheat products using calcium as an internal tracer

Reversed-phase high-performance liquid chromatography (RP-HPLC) was used for rutin (quercetin-3-rutinoside) determination in selected buckwheat products (whole meal flour, broken seeds, seed hulls, herbs and baked cereal breads). The effect of various thermal procedures on content of rutin was evaluated using calcium as an internal tracker to correct changes in mass and composition of the buckwheat products. These factors are very seldom taken into account. The results show non-significant changes in rutin levels obtained in whole meal flour and broken seed samples after thermal treatment up to 150°C. Higher temperature already caused sudden fall in the observed rutin concentrations. The evaporation of some volatile compounds and degradation products can decrease the mass of the samples and formally increase the content of rutin (35.5 ±4.7 mg per 100 g for whole meal flour and 10.2 ±0.4 mg per100 g for broken seeds at 150°C). Serious decrease of rutin contents at elevated temperatures (>150°C) can be explained by its degradation (by breaking off the C-C bond in quercetin-3-rutinoside moiety) and/or evaporation (24.3 ±1.4 mg per 100 g for whole meal flour and 3.06 ±0.3 mg per100 g for broken seeds at 180°C). In case of baked cereal breads the level of rutin changed in dependence on the ratio between buckwheat and corn flour. Longer time leaching and higher temperature implicate higher rutin content in infusions prepared from buckwheat seed hulls and herbs.

Verification of animal species in ham and salami by DNA microarray and Real time PCR methods

Consumer protection and detecting of adulteration is very important and has a wide societal impact in the economic sphere. Detection of animal species in meat products and the use of combining different methods is one of the means to achieve relevant product status. The aim of this study was to reveal whether or not the products label clearly meets the content declared by producer. In our study, 29 samples of meat products such as salami and ham obtained from stores and supermarkets in Slovakia were analyzed to detect the existing animal species according to the product label the use of Chipron LCD Array Analysis System, Meat 5.0. Products in which the presence of non-declared animal species has been detected were subjected to testing by the innuDETECT PCR Real-Time Kit, repeatedly. The results showed that 20 (68.96%) samples were improperly labeled. From in total 14 tested ham samples 11 (78.57%) products exhibited non-conformity with declared composition. Tested salami samples (15) revealed 9 (60%) incorrectly labelled products. The results obtained by DNA Microarray and Real Time PCR methods were identical, and both methods should be extensively promoted for the detection of animal species in the meat and meat products.

Microbiological quality of fresh and heat treated cow's milk during storage

The aim of the present study was to evaluate the microbiological quality of raw milk from milk vending machine and heat treated milk during storage. There were analyzed 120 samples of milk (30 samples of fresh milk, 30 samples of raw milk stored 4 day at 4 °C, 30 samples of heat treated milk - 70 °C  stored 4 day at 4 °C and 30 samples of heat treated milk - 100 °C stored 4 day at 4 °C). Total viable counts (TVC), coliform bacteria (CB) and microscopic filamentous fungi (MFF) were determined by microbiological analysis. Plate dilution method were used for microbiological analysis. The number of total viable counts (TVC) in fresh milk ranged from 4.08 log KTJ.mL-1 to 4.89 CFU.mL-1. TVC in raw milk after storage ranged from 5.31 log CFU.mL-1 to 6.81 log CFU.mL-1. TVC in heat treated milk with temperature 70 °C after storage ranged from 3.89 log CFU.mL-1 to 4.45 log CFU.mL-1 and TVC in heat treated milk with temperature 100 °C after storage ranged from 2.96 log KTJ.mL-1 to 3.91 log KTJ.mL-1 in heat treated milk with temperature 100 °C after storage. The number of CB were in range from 1.49 log CFU.mL-1 to 1.89 log CFU.mL-1 in fresh milk, from 1.99 log CFU.mL-1 to 2.61 log CFU.mL-1 in raw stored milk. Coliform bacteria were not present in heat-treated milk samples. The values of MFF ranged from 0 log CFU.mL-1 to 2.01 log CFU.mL-1 in fresh milk, from 1.43 log CFU.mL-1 to 3.98 log CFU.mL-1 in raw milk after storage, from 1.33 log CFU.mL-1 to 3.41 log CFU.mL-1 in heat treated milk with temperature 70 °C after storage and from 1.30 log CFU.mL-1 to 3.32 log CFU.mL-1 in heat treated milk with temperature 100 °C after storage.

Authentication of caprine milk and cheese by commercial qPCR assay

The objective of the study was to investigate potential adulteration of commercial caprine milks and cheeses with bovine milk using commercial qPCR assay. The assay comprised of bovine-, ovine- and caprine-specific primers and TaqMan probe and mammalian internal control. Specificity, sensitivity, linearity, reproducibility and efficiency of the bovine assay were tested as well. Specificity was verified by running reaction on the DNA of other milk-producing species (caprine and ovine) and made-up bovine-caprine (v/v) milk mixes. In both experiments, a bovine DNA fragment was amplified whereas no amplification was obtained from the other species. Sensitivity, linearity, reproducibility and efficiency were tested on 10-fold dilution series of 10 ng bovine DNA. The assay has shown good linearity (R2 = 0.983) within whole range, with efficiency of 86% and excellent reproducibility (SD around the CT for the technical replicates <0.5). The sensitivity was adequate, as calculated LOD and LOQ were 1.44 pg and 2.94 pg of bovine DNA, respectively. Finally, the assay was used to authenticate 5 caprine milk samples and 5 caprine cheese samples, purchased from local supermarkets. Totally, 1 milk sample has shown the fluorescence signal, which exceeded baseline in cycle 39.01 ±0.69. However, the signal was above LOD and LOQ suggesting that there could not be unambiguously declared any adulteration with bovine milk. Amplification of bovine-specific DNA was not observed in the other samples indicating products were not adulterated. The commercial qPCR assay has proved that real-time PCR assays, as well as DNA-based techniques in a general, are the excellent and reliable tools for fighting with frauds in the food industry and protecting the public health. 

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.