Josef Kameník

The aim of the study was to evaluate the dietary effect of condensed tannins (CT) from red quebracho (Schinopsis lorentzii) and broiler age on the physicochemical properties, mineral composition, and amino acid content in the meat of broilers ...

This study aimed to?evaluate the effects of?dietary administration of?peppermint (Mentha piperita) alone and in?combination with southernwood (Artemisia abrotanum) on?performance, body and carcass composition, physicochemical characteristics, ...

Protective cultures are an increasingly industrially relevant biopreservation tool for meat and meat products, responding to simultaneous demands for microbiological safety, extended shelf life, and reduced reliance on synthetic preservatives within clean-label frameworks. This review summarizes current advances in protective cultures applied to meat systems, with emphasis on technological functions, efficacy boundaries, and safety-related due diligence. We discuss the dominant inhibitory mechanisms of lactic acid bacteria and related protective taxa—acidification, competitive exclusion, and antimicrobial metabolites (including bacteriocins)—and highlight why performance is strongly strain- and matrix-dependent under realistic storage conditions. Practical applications are reviewed across raw meats (spoilage delay under refrigeration and vacuum/MAP) and processed or ready-to-eat products, where post-processing surface application emerges as a critical control point for limiting Listeria monocytogenes outgrowth during chilled storage. Key implementation constraints include technological compatibility and sensory neutrality, which are influenced by product buffering capacity, salt content, available fermentable substrates, packaging atmosphere, and temperature. From a safety perspective, we synthesize evidence on antimicrobial resistance in food-associated cultures and outline contemporary qualification strategies combining phenotypic susceptibility testing with genome-based screening to exclude acquired and potentially transferable resistance determinants. Overall, protective cultures should be viewed as a targeted hurdle integrated into holistic preservation systems rather than a standalone substitute for hygiene and process control.

Plant analogues of animal foods are currently being increasingly produced worldwide to supply the market with alternative products made from plant-based ingredients. In this study, the acrylamide (AA) content was determined by coupled liquid chromatography with mass spectrometry before and after heat treatment of plant-based meat product alternatives (PBMAs; burger patties, steaks, nuggets, schnitzels), authentic meat products (nuggets, strips¸ schnitzels), plant-based cheese alternatives (PBCAs) and authentic cheese. In PBMAs without breadcrumb coating (burgers, steaks), the AA concentrations before as well as after heat treatment remained below the method limit of quantification (20 g/kg), while in PBMAs with breadcrumb coating such as nuggets or schnitzels, frying statistically significantly (p < 0.05) increased the AA content from 28.5 (min-max <20-98) g/kg to 44.5 (28-170) g/kg. A similar trend was observed for authentic meat products with breadcrumb coating – increase of AA after heat treatment from 15.5 (<20-33) g/kg to 36.5 (<20-64) g/kg. In both PBCAs and authentic cheese, frying in breadcrumb coating also increased AA concentrations (to 20.0 (<20-42) g/kg and 31.5 (<20-39) g/kg, respectively). It was found that the source of the AA increase during heat treatment was therefore the breadcrumb coating, not the plant analogues themselves or authentic meat products or cheeses. Only in PBCAs without breadcrumb coating produced from minced almonds, heat treatment increased AA contents to as much as 1,217 g/kg, which is already a high-risk concentration. Our results imply the need for deeper investigation into AA content in heat-treated PBCAs made from minced almonds.

The aim of this study was to evaluate microbiological, physicochemical, instrumental, and sensory parameters of jerky and biltong and to identify potential associations affecting their overall quality and safety. In total, 39 samples of various types of jerky (beef, turkey, venison, pork, and chicken) and 7 samples of beef biltong were analysed. The jerky and biltong samples showed low water activity values (a_w < 0.800), which makes them microbially stable products that can be stored at room temperature without the risk of further bacterial growth. Listeria monocytogenes was not detected in any of the 92 analysed samples. From a food safety perspective, the finding of Salmonella Enteritidis in one chicken jerky sample was unacceptable. Total viable count (TVC) values showed high variability, with findings over 8 log CFU/g. These high TVC values indicate heavily contaminated meat used to prepare dried products, or errors in the technological process that allowed bacterial growth. Both are unacceptable from a food quality and safety perspective. This means that more attention needs to be paid to the production process by processors, as well as by competent authorities. The analyses confirmed a high average protein content (>50%) in the final products and a low average fat content ( 0.05). Similarly, there was no difference in TBARS values (p > 0.05). Microbial counts (TVC, lactic acid bacteria, and Enterobacteriaceae) were strongly affected by water activity, which was strongly negatively correlated with dry matter and its components such as proteins and ash/NaCl.

Efforts to reduce sodium chloride levels in meat products within the European Union are closely aligned with the World Health Organization’s recommendation to limit daily sodium intake to a maximum of 5 g per person. The nutritional significance of excessive salt intake is well-established, and the role of sodium chloride in meat products is not only crucial for sensory quality but also for hygienic safety. The aim of this study was to evaluate the impact of varying salt concentrations (1.4%, 1.6%, 1.8%, and 2.0%) on selected quality parameters of two common processed meat products: grilling sausages (Špekáčky) and frankfurters (Wiener Würstel). Sensory analysis was conducted with a relatively high number of trained evaluators (n = 73 for Wiener Würstel; n = 63 for Špekáčky). The results indicated that moderate salt reduction had no statistically significant effect (p > 0.05) on either the sensory attributes or the hygienic quality of the products. The method of salt content determination was shown to be critical for accurate assessment. These findings suggest that both types of reformulated products with reduced sodium content can be effectively used in production without compromising quality. Therefore, such formulations may serve as viable strategies for the food industry to contribute to public health objectives by reducing dietary sodium intake.

With increasing popularity of food delivery services, the microbial safety of transported meals should be ensured. An effect of the type of a meal (cooked rice; mashed potatoes; mushroom sauce), inner primary packaging (sugarcane bagasse [SB] tray; polypropylene [PP] tray), secondary container (polyester/polyethylene foam/aluminum foil [PPA] bag; PP box) on the time interval of the internal hot ready-to-eat (RTE) meal temperature decrease to the value critical for Bacillus cereus growth (40 °C) was tested during a simulated delivery; in aliquot samples of the same meals, B. cereus growth was quantified presuming a natural contamination of the meals. Type of a meal had no effect on the tested time interval (p > 0.05). Packaging a meal in the PP tray as compared to the SB tray and inserting primary trays into the PP box instead of PPA bag delayed (p < 0.05) the internal meal temperature decrease by 50 and 15 min, respectively. Average B. cereus counts in the naturally contaminated meals after the four-hour culturing at 40 °C was 2.99 log CFU·g⁻¹. It was concluded that a hot RTE meal delivered up to four hours under the tested conditions is not likely to facilitate B. cereus growth above unacceptable levels.

With increasing popularity of food delivery services, the microbial safety of transported meals should be ensured. An effect of the type of a meal (cooked rice; mashed potatoes; mushroom sauce), inner primary packaging (sugarcane bagasse [SB] tray; polypropylene [PP] tray), secondary container (polyester/polyethylene foam/aluminum foil [PPA] bag; PP box) on the time interval of the internal hot ready-to-eat (RTE) meal temperature decrease to the value critical for Bacillus cereus growth (40 °C) was tested during a simulated delivery; in aliquot samples of the same meals, B. cereus growth was quantified presuming a natural contamination of the meals. Type of a meal had no effect on the tested time interval (p > 0.05). Packaging a meal in the PP tray as compared to the SB tray and inserting primary trays into the PP box instead of PPA bag delayed (p < 0.05) the internal meal temperature decrease by 50 and 15 minutes, respectively. Average B. cereus counts in the naturally contaminated meals after the four-hour culturing at 40 °C was 2.99 log CFU/g. It was concluded that a hot RTE meal delivered up to four hours under the tested conditions is not likely to facilitate B. cereus growth above unacceptable levels.

The aim of this study was to assess the germination and growth of two strains of Bacillus cereus following the artificial inoculation of six selected hot dishes with spores which were then stored at temperatures of 40, 50, and 60 °C for 0.5, 1.0, 2.0, 2.5, 3.0, and 4.0 h. The water activity of the prepared meals varied between 0.967 and 0.973 and the salt content between 0.74 and 1.40%. The pH value of four dishes exceeded 6.0, but for two (tomato sauce and ratatouille) it was 4.6. The tested strain DSM 4312 showed good growth abilities and attained a population exceeding 6.0 log CFU/g within 4 h at 40 °C in foods with pH values > 6.0. The study demonstrated that a drop in food temperatures to 40 °C is risky, while no growth of B. cereus was detected within 4 h at 50 and 60 °C. The growth rate of B. cereus is conditioned not merely by environmental conditions (temperature, pH values, food composition), but also by the bacterial strain.

Meat aging is an important process that affects the quality of meat and is traditionally used mainly for beef. However, in recent years, there has been an increasing demand for pork products subjected to dry aging. The aim of this study was to compare selected parameters (microbiological quality, instrumental analyses of texture and color of meat, weight loss) of pork neck and loin with bone and skin together subjected to dry aging for 14 days. The microbiological profile (total viable psychrotrophic count, Enterobacteriaceae, psychrotrophic lactic acid bacteria, Pseudomonas spp.) on the surface of the meat with the skin and the lateral cutting surfaces without skin was compared on the first day after slaughter and after 14 days of dry aging. The results of this study demonstrated that dry aging did not significantly deteriorate the microbiological profile. Statistically significant weight losses were observed after 14 days of aging. The dry aging of pork had no significant effect on lightness (L*), redness (a*), and shear force. Significant differences were observed for yellowness (b*) and meat hardness (p < 0.05).