Tofu processing: selected parameters from the seeds to the final products and by-products Daniela Lukáčová, Martina Fikselová, Radoslav Židek, Jozef Čapla, Peter Zajác Scifood, 2026 The efficiency of soy food production, particularly tofu, depends on a complex of physicochemical properties of soybean seeds (Glycine max). This study analyzes 187 soybean samples to evaluate the primary determinants of tofu yield/production. The main objective was to analyze the relationships among selected physicochemical properties of soybeans and tofu production. The methods applied were Near-Infrared Spectroscopy (NIR), physical parameters (hydration coefficient, thousand seed weight [TSW]), and correlation and regression analyses to identify relationships among hydration potential, seed properties, dry matter content, and the amino acid profile. Our results show that the hydration potential is strongly positively associated with seed dry matter content, indicating that dry matter is a critical predictor of water absorption efficiency. Raw tofu yield demonstrated a clear positive correlation with the physical properties of the seeds, including TSW and the hydration coefficient. An original contribution of this work is the identification of a negative amino-acid signature associated with reduced tofu yield. Aspartic acid, histidine, alanine, and glycine showed significant negative correlations with tofu raw yield, whereas proline content showed a slight positive association.
Biodegradable organic waste as a substrate for edible insect production: regional availability and conversion potential in Slovakia Radoslav Židek, Vladimír Vietoris, Radovan Kasarda, Nina Moravčíková, Miroslav Palko, Maroš Palko, Ľubomír Belej Scifood, 2026 The global demand for sustainable protein sources is rapidly increasing due to environmental pressures associated with conventional livestock production. This study integrates regional waste statistics, spatial analysis, and species-specific bioconversion modelling to estimate the theoretical potential of compostable municipal waste for insect-derived protein production in Slovakia. Regional data on municipal waste generation and treatment were obtained from the Statistical Office of the Slovak Republic for eight NUTS-3 administrative regions (2024 baseline). Two complementary approaches were applied: a conservative empirical approach based on R03 organic recovery flows, and a model-based estimation using 40% of total municipal waste as the organic fraction (OFMSW). Four insect species were evaluated: Hermetia illucens (black soldier fly), Tenebrio molitor (yellow mealworm), Acheta domesticus (house cricket), and Locusta migratoria (migratory locust). Biomass conversion was modelled using deterministic mass-balance equations with species-specific bioconversion efficiencies (0.16–0.20 kg DM per kg substrate DM) and protein content coefficients (47–60% DM), each selected as the mid-range estimate from primary experimental literature. The results reveal pronounced regional heterogeneity in compostable substrate availability, with western and densely populated regions exhibiting the highest absolute quantities. Protein production potential varied substantially across species and regions, with T. molitor demonstrating both the highest biomass yield and the highest protein production density per unit substrate, while L. migratoria exhibited the highest protein content per unit produced biomass. Expanded sensitivity analysis (±30% for bioconversion yield coefficients, ±15% for dry matter fraction, ±10% for protein content) confirmed the directional robustness of model outputs while quantifying the substantial uncertainty range inherent in regional bioconversion estimates. A regulatory scenario based on Regulation (EC) No. 1069/2009 indicates that approximately 35% of the theoretical substrate base is currently compliant for use in insect rearing for animal feed, representing the practically realisable fraction of the identified bioconversion potential. The study identifies key nutritional compatibility constraints between waste stream composition and insect species requirements, highlighting the importance of substrate blending for efficient bioconversion. These findings provide a spatially explicit foundation for planning circular bioeconomy strategies integrating waste management and sustainable insect protein production in Slovakia.
PHENOLIC CONTENT OF APPLE POMACE AFFECTED BY THEIR MICROWAVE IRRADIATION Martina Fikselová, Silvia Jakabová, Radoslav Židek, Lucia Zeleňáková, Jozef Čapla, Simona Kunová, Paulína Letková, Jana Kolačkovská Journal of Microbiology Biotechnology and Food Sciences, 2025 Thermal degradation mechanisms and products of some polyphenols, such as quercetin and rutin, have been intensively observed. The structural changes of polyphenols caused by food processing, may lead to different changes. The aim of this work was to test the changes of TPC, selected individual phenols and antioxidant activity of apple pomace gained from producers and compared to the samples prepared in laboratory conditions caused by microwave irradiation. Antioxidant activity was determined by the DPPH method, total polyphenolic content with use of Folin-Ciocalteau reagent and individual phenolic substances by HLPC -DAD method. The control samples were treated by the microwave radiation for 1 min. in a microwave oven at 650 W. The results of DPPH method showed an increased inhibition of DPPH radical, so higher antioxidant activity, mainly at laboratory prepared samples of pomace was detected. At TPC evaluation, an increase in the content of total polyphenols was observed similarly, at 3 of 4 irradiated samples the significant increase was detected at the level of significance p=0.001. Several individual phenols were detected after irradiation of pomace in higher amounts as well. Application of microwave irradiation in the extraction process might lead to significant increase of the total phenolic content.
Traces of Human-Mediated Selection in the Gene Pool of Red Deer Populations Nina Moravčíková, Radovan Kasarda, Radoslav Židek, John Colin McEwan, Rudiger Brauning, Tomás Landete-Castillejos, Louis Chonco, Juraj Ciberej, Jaroslav Pokorádi Animals, 2023 In this study, we analysed the effect of human-mediated selection on the gene pool of wild and farmed red deer populations based on genotyping-by-sequencing data. The farmed red deer sample covered populations spread across seven countries and two continents (France, Germany, Hungary, Latvia, New Zealand, Poland, and Slovakia). The Slovak and Spain wild red deer populations (the latter one in a large game estate) were used as control outgroups. The gene flow intensity, relationship and admixture among populations were tested by the Bayesian approach and discriminant analysis of principal components (DAPC). The highest gene diversity (He = 0.19) and the lowest genomic inbreeding (FHOM = 0.04) found in Slovak wild population confirmed our hypothesis that artificial selection accompanied by bottlenecks has led to the increase in overall genomic homozygosity. The Bayesian approach and DAPC consistently identified three separate genetic groups. As expected, the farmed populations were clustered together, while the Slovak and Spanish populations formed two separate clusters. Identified traces of genetic admixture in the gene pool of farmed populations reflected a strong contemporary migration rate between them. This study suggests that even if the history of deer farming has been shorter than traditional livestock species, it may leave significant traces in the genome structure.
Czechoslovakian wolfdog genomic divergence from its ancestors canis lupus, german shepherd dog, and different sheepdogs of european origin Nina Moravčíková, Radovan Kasarda, Radoslav Židek, Luboš Vostrý, Hana Vostrá-Vydrová, Jakub Vašek, Daniela Čílová Genes, 2021 This study focused on the genomic differences between the Czechoslovakian wolfdog (CWD) and its ancestors, the Grey wolf (GW) and German Shepherd dog. The Saarloos wolfdog and Belgian Shepherd dog were also included to study the level of GW genetics retained in the genome of domesticated breeds. The dataset consisted of 131 animals and 143,593 single nucleotide polymorphisms (SNPs). The effects of demographic history on the overall genome structure were determined by screening the distribution of the homozygous segments. The genetic variance distributed within and between groups was quantified by genetic distances, the FST index, and discriminant analysis of principal components. Fine-scale population stratification due to specific morphological and behavioural traits was assessed by principal component and factorial analyses. In the CWD, a demographic history effect was manifested mainly in a high genome-wide proportion of short homozygous segments corresponding to a historical load of inbreeding derived from founders. The observed proportion of long homozygous segments indicated that the inbreeding events shaped the CWD genome relatively recently compared to other groups. Even if there was a significant increase in genetic similarity among wolf-like breeds, they were genetically separated from each other. Moreover, this study showed that the CWD genome carries private alleles that are not found in either wolves or other dog breeds analysed in this study.
SPORTS TALENT SEARCH: GENES VERSUS MOTOR TESTS Šimonek, J., Židek, R., Шимонек, Я., Жидек, Р. Human Sport Medicine, 2021 J. Šimonek 1, jsimonek@ukf.sk, ORCID: 0000-0003-4242-4891, R. Židek 2, r.a.d.o.z.i.d.e.k@gmail.com, ORCID: 0000-0003-4751-1257 1Constantine the Philosopher University in Nitra, Nitra, Slovakia, 2Slovak University of Agriculture in Nitra, Nitra, Slovakia Шимонек Яромир, PhD в области спортивной кинантропологии, профессор кафедры физического воспитания и спорта, педагогический факультет, Университет имени Константина Философа. Ул. Андрея Глинки, 1, 94974, г. Нитра, Словакия. E-mail: jsimonek@ukf.sk, ORCID: 0000-0003-4242-4891. Жидек Радослав, PhD в области генетики, доцент кафедры гигиены и безопасности пищевых продуктов, факультет биотехнологии и пищевых наук, Словацкий сельскохозяйственный университет. Ул. Андрея Глинки, 2, 94976, г. Нитра, Словакия. E-mail: r.a.d.o.z.i.d.e.k@gmail.com, ORCID: 0000-0003-4751-1257.
Detection of adulteration of traditional Slovak bryndza ewe’s cheese with cow’s lump cheese by isoelectric focusing of gamma caseins Peter Zajác, Elena Beňová, Radoslav Židek, Jozef Čapla, Lucia Benešová, Jozef Čurlej, Jozef Golian International Journal of Food Properties, 2021 “Slovak bryndza” is a traditional Slovak cheese manufactured by milling a lump of matured ewe’s cheese or by milling a mixture of lump ewe’s cheese and lump cow’s cheese. The percentage of lump ewe’s cheese is greater than 50% w/w dry matter. Differences in the purchase prices of ewe’s and cow’s milk create the potential for adulteration. The detection of cow’s milk compounds by isoelectric focusing of γ-caseins after plasmolysis is a suitable method for the determination of adulteration of this traditional cheese. The analysis and final results may be affected by factors affecting laboratory activity and biological factors. Biological factors are manifested primarily as variations in the casein content of ewe’s and cow’s milk. Despite this variation, this method may also be used for quantification purposes. We were able to establish a reliable calibration line from the internal reference materials prepared in our laboratory. The mean composition of Slovak bryndza cheese determined in our research was protein 18.7 ± 1.9 g 100 g−1, fat 24.0 ± 1.8 g 100 g−1, lactose 1.5 ± 1.9 g 100 g−1, ash 4.5 ± 0.3 g 100 g−1, fat in dry matter 49.3 ± 2.6 g 100 g−1, casein 18.4 ± 1.9 g 100 g−1, gamma casein 0.60 ± 0.19 g 100 g−1, and bovine-to-ovine gamma casein ratio 0.65 ± 0.12 g 100 g−1.
Risk assessment of fat-soluble vitamins based on genetic score predictive model Journal of Hygienic Engineering and Design, 2020
Maximal amount of o2 per unit of time can suggest improvements in cardio-respiratory fitness in response to exercise training Journal of Hygienic Engineering and Design, 2020
Analysis of selection signatures in the beef cattle genome Nina Moravčíková, Radovan Kasarda, Luboš Vostrý, Zuzana Krupová, Emil Krupa, Kristína Lehocká, Barbora Olšanská, Anna Trakovická, Rudolf Nádaský, Radoslav Židek, Ľubomír Belej, Jozef Golian Czech Journal of Animal Science, 2019
Identification of the common carp (Cyprinus carpio) species using real-time PCR methods Zywnosc Nauka Technologia Jakosc Food Science Technology Quality, 2012
Optimization of ELISA method for detection of bovine β-lactoglobulin in sheep milk and sheep milk products Milchwissenschaft, 2011
Genetic admixture in pig population observed by microsatellite markers Archiv Fur Tierzucht, 2011
Application of conventional microsatellite markers and quantitative trait loci in porcine genetic research Magyar Allatorvosok Lapja, 2009
Diversity analysis of Hucul horse population based on molecular genetic data Magyar Allatorvosok Lapja, 2009
The BLUP-animal model for the estimation of the breeding value of show jumping horses Magyar Allatorvosok Lapja, 2008
Genetic structure of nine horse populations Monika Burócziová, J. Říha, R. Židek, J. Trandžík, D. Jakabová Acta Universitatis Agriculturae Et Silviculturae Mendelianae Brunensis, 2008
