Tomas Bata University in Zlín
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Role of pectin in maintaining the physicochemical, textural, rheological, and organoleptic properties of model quark cheese spreads during simulated vibrations and storage
No full textThis study examined the effects of incorporating pectin and applying simulated mechanical vibrations on the physicochemical, textural, rheological, and organoleptic attributes of Quark cheese spreads (QCS) over a storage period of 30 days (6 ± 2 °C). The QCS model samples were prepared with pectin concentrations of 0.50, 0.75, and 1.00 % w/w and subjected to vibrational loading to simulate transportation conditions. Key physicochemical parameters, including dry matter (DM), fat and protein content, water activity, and pH, were measured on day 2 and 30 after preparation. Vibrations significantly affected the hardness, spreadability, and water holding capacity (WHC) of the samples, with increased pectin concentrations leading to greater hardness and greater force required for spreading, particularly in non-vibrated samples. Rheological analysis revealed that vibrational loading reduced viscoelastic moduli (G' and G”), with the elastic character prevailing in all samples (tan δ < 1). Sensory evaluation demonstrated a minimal influence of vibrations on assessor perception, except at higher pectin concentrations. It could be concluded that vibrations negatively affected the textural and viscoelastic properties and WHC of the QCS model products. To avoid the problems mentioned above, the data presented in this study may be useful in developing formulations and transportation systems for QCS products.Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT; Tomas Bata University in Zlín, TBU, (IGA/FT/2025/007); Tomas Bata University in Zlín, TBU; DKRVO, (RP_CPS_2024_28_006)Internal Grant Agency of the Tomas Bata University in Zln [IGA/FT/2025/007]; Ministry of Education, Youth and Sports of the Czech Repub-lic-DKRVO [RP_CPS_2024_28_006
Study of natural dyes' liposomal encapsulation in food dispersion model systems via high-pressure homogenization
Get PDFThe aim of this study was to investigate the encapsulation of natural food dyes incorporated into liposomes in terms of particle size, rheological and colour properties, zeta potential, and encapsulation efficiency. The liposomes contained dye substances of anthocyanins from freeze-dried raspberry powder (R), copper complexes of chlorophyllins (C), or commercial-grade β-carotene (B). The phospholipid envelope was composed of sunflower lecithin and carboxymethylcellulose sodium salt as a surface stabilizer treated by high-pressure homogenization. The median particle diameter of R and C systems fluctuated around 200 nm, while B systems showed a broader range of 165–405 nm. The rheological results demonstrated a specific flow behaviour pattern dependent on the rotational shear applied, indicating a flow-induced structural change in the dispersions. Samples were characterized by a translucent profile with relatively high lightness, accompanied by a hue angle (h*) typical of the dye encapsulated. The zeta potential was approx. −30 mV, showing electrokinetically stabilized dispersions. The encapsulation efficiency (EE) varied significantly, with the highest EE observed for anthocyanins, ranging from 36.17 to 84.61%. The chlorophyll encapsulation was the least effective, determined in the range between 1.82 and 16.03%. Based on the suitability index, optimal liposomal formulations were evaluated by means of the Central Composite Design (CCD)
Eco-friendly solid polymer electrolytes doped with NaClO4 for next-generation energy storage devices: structural and electrochemical insights
Get PDFOne of the environmental challenges of energy storage devices is ensuring sustainable manufacturing and disposal practices to minimize hazardous waste. In this study, a blend of green polymers, chitosan (CS) and polyvinyl alcohol (PVA) is used as a host matrix to create flexible ion-conducting films, with ion donating NaClO4 added to enable ion transport. A significant polymer-salt interaction is evident from the FTIR investigations. Impedance spectra reveal a decrease in the bulk resistance with increasing salt content, highlighting the potential of the system for energy storage applications. The optimized bulk conductivity is improved from (1.43 ± 0.26) × 10−8 S cm−1 for the pure blend to (5.23 ± 0.27) × 10−4 S cm−1 for the composition with 35 wt% NaClO4. The ion transport properties, investigated using the Schutt and Gerdes (S-G) model, reveal a strong dependency of conductivity on the carrier concentration over ion mobility. Linear sweep voltammetry (LSV) showed the high electrochemical stability of PCP35 up to 2.6 V. The ionic transference number close to unity confirms the purely ionic nature of the optimized composition. The electric-double layer capacitor (EDLC) comprising the optimized electrolyte composition delivers a specific capacitance of 20.58 F g−1 at 0.05 mA g−1, with energy and power densities of 2.69 W h kg−1 and 97 W kg−1, respectively.Directorate of Minorities in Bengaluru, India [DOM/Fellowship/CR-10/2019-20
Metal cations switch geometry of β-cyclodextrin complexes
No full textCationic guests with an adamantylphenyl moiety can form two distinct arrangements with the conical β-cyclodextrin macrocycle. Different metal cations were found to promote the formation of one of the two possible forms, depending on their van der Waals radii. Bulkier ions prefer the wider secondary rim of β-cyclodextrin, pushing the cationic part of the guest towards the narrower primary rim, and vice versa.Internal Funding Agency of Tomas Bata University in Zlimath;n [IGA/FT/2025/001]; University of Jyvaskyl
Participation reimagined: beyond the one-dimensional approach to participation in adult learning and education
Get PDFThis article re-evaluates the concept of participation in adult learning and education (ALE), introducing a novel framework based on Kelty’s work on modes of participation. The article contends that investigations into ALE must venture beyond simplistic, one-dimensional approaches to participation that focus solely on participant numbers or hours dedicated to organised learning, as these approaches fail to capture the complexity of engagement in organised adult learning. The research framework introduced in this article decomposes participation into seven distinct dimensions: educative dividend, goals and tasks, resource control, exit, voice, visible metrics and affective capacity. This article demonstrates the utility of the new framework through analysis of data from a 2023 nationally representative survey conducted in the Czech Republic. For a sub-sample of non-formal education (NFE) participants, we find clear sociodemographic patterns of scoring across the dimensions, with education level, employment and occupation status, and employer size being the most articulate. By applying cluster analysis, we identify two subgroups: the high engagement participation (HEP) cluster and the low engagement participation (LEP) cluster. Overall, our findings contribute towards constructing a new typology based on the characteristics of participation itself, not on individual characteristics, such as motivation or attitudes
Enhancing commercial gourmet oil quality: The role of dried cayenne pepper eed (capsicum annuum L.) as a natural additive
No full textThis study assessed the potential of dried Cayenne pepper (CP; Capsicum annuum L.) as a natural additive to rice bran oil (RBO), grape seed oil (GSO), and virgin olive oil (OO). Key analyses included peroxide and acid values, oxidative stability (Rancimat method), the composition of fatty acids (FAs) (GC-FID method), antioxidant activity (AA; DPPH method), and antimicrobial properties (disc diffusion method). Capsaicin and the dihydrocapsaicin contents in CP were quantified (HPLC-DAD method) as 1499.37 ± 3.64 and 1449.04 ± 5.14 mg/kg DW, respectively. Oleic acid (C18:1cis n9) dominated in OO (69.70%), OO-CP (69.73%), and RBO-CP (38.97%), while linoleic acid (C18:2cis n6) prevailed in RBO (41.34%), GSO (57.93%), and GSO-CP (58.03%). The addition of CP influenced the FA profile, particularly linoleic acid in OO and RBO, and all FAs in GSO. Peroxide and acid values increased significantly in RBO and GSO upon CP addition, but induction times remained unaffected. The strongest AA (77.00 ± 0.13%) was observed in OO-CP. Cayenne pepper significantly enhanced the antioxidant profiles of all oils compared to the counterparts. However, the antimicrobial activity was weak (≤5.0 mm inhibition zones) against tested microorganisms. These findings support CP as a functional additive for enhancing the nutritional and functional properties of gourmet oils, while highlighting the need for further optimization to improve stability and bioactivity.Faculty of Agrobiology and Food Resources; Ministry of Education, Science, Research and Sport of Slovakia; Agentúra na Podporu Výskumu a Vývoja, APVV, (APVV-22-0348, APVV-21-0206); Agentúra na Podporu Výskumu a Vývoja, APVV; Nadácie Tatra Banky, (2024VZDinst038); Nadácie Tatra Banky; Kultúrna a Edukacná Grantová Agentúra MŠVVaŠ SR, KEGA, (016SPU-4/2024); Kultúrna a Edukacná Grantová Agentúra MŠVVaŠ SR, KEGA; Slovak University of Agriculture, (2/2024)Slovak University of Agriculture; Grant Agency of the Faculty of Agrobiology and Food Resources [2/2024, 2024VZDinst038]; Slovak University of Agriculture (SUA) in Nitra (Slovakia) [KEGA 016SPU-4/2024]; Cultural and Educational Grant Agency of the Ministry of Education, Science, Research and Sport of Slovakia [APVV-22-0348, APVV-21-0206]; Slovak Research and Development Agenc
Hydrophilization of rice seeds by plasma treatments – Super-hydrophilic surface finish and hydrophobic recovery
Get PDFThe hydrophobic character of rice seeds protects them from quick water adsorption and, thus, premature germination. This property is, however, a drawback in modern agriculture, where rapid and uniform germination represents a high-quality trait. A method for rapid hydrophilization of the Lomello variety of rice is presented. The rice seeds were treated with low-pressure gaseous plasma to tailor the wettability. The treatment of seeds with hulls with oxygen plasma afterglow enabled the super-hydrophilic surface finish within 10 ms. Such extremely fast hydrophilization was attributed to irreversible surface oxidation by neutral oxygen atoms whose flux onto the seeds was approximately 3 × 1023 m−2s−1. Dehulled seeds were made super-hydrophilic by subsequent treatments with hydrogen and oxygen plasma, and the required dose of O atoms was between 2 × 1023 and 6 × 1024 m−2. Larger doses caused a loss of the super-hydrophilicity. Hydrophilization kinetics is proposed and supported by measuring surface wettability, morphology, and composition using various techniques. The hydrophobic recovery of seeds with hulls is marginal within the first few days after plasma treatments, but dehulled seeds lose the super-hydrophilic surface finish within a few minutes after the plasma treatment when stored at ambient conditions.European Commission, EC; Horizon 2020, (101058020)European' Union' [101058020]; Horizon Europe - Research Infrastructures (RIS) [101058020] Funding Source: Horizon Europe - Research Infrastructures (RIS)European' Union' [101058020]; Horizon Europe - Research Infrastructures (RIS) [101058020] Funding Source: Horizon Europe - Research Infrastructures (RIS
Antibacterial and biodegradable PLA-based nanofibers loaded with natural phenolic monoterpenes for sustainable biomedical or food application
No full textAntibacterial biodegradable PLA-based nanofibers loaded with phenolic monoterpenes - thymol, eugenol, carvacrol, and cinnamaldehyde, were prepared by electrospinning. The effect of bioactive molecule on the surface, thermal, morphological, and biological properties has been investigated about the potential pharmaceutical and food processing applications. Fiber diameters ranged from 320 nm for PLA fibrous mat up to 480 nm for PLA membrane with 6 % thymol. All the prepared active nanofibers exhibited hydrophobic surfaces with a slightly decreasing contact angle after the incorporation of phenols. Antimicrobial testing proved a strong efficiency against Escherichia coli and Staphylococcus aureus, depending on the specific type and content of the bioactive compound. A significant biofilm formation reduction of bioactive PLA nanofibers was revealed against tested microorganisms. Modification of PLA fibers with active molecules did not significantly affect the biodegradation kinetics in comparison to PLA samples with their absence. This study demonstrates the high potential of newly developed PLA-based/phenol nanofibrous membranes for use as antibacterial and antifouling systems applicable in wound dressings and food packaging.European Union [862910]; Internal Grant Agency of Tomas Bata University in Zlin [IGA/FT/2024/004, IGA/FT/2025/006]; Slovak Research Agency VEGA [2/0137/23
Strengthening the sustainability of energy critical entities through a business continuity management system
Get PDFEnergy supply is currently considered a key area that is essential for the functioning of the entire society, remaining one of the most fundamental sectors of critical infrastructure worldwide. However, the functionality of energy systems is threatened by a number of threats from various areas, such as natural influences, technological threats, terrorism, and even state-supported organized attacks. For this reason, there is an active effort by all interested parties to achieve a sufficient resilience and sustainability level of these systems. Currently, various tools are used for this purpose, the essence of which is to ensure the preparedness of energy systems. Primarily, basic dependable systems aspects are applied according to the planning documentation and according to the N-1 principle from the transmission system code. These tools are functional and very proven in practice. However, the sprawling threat landscape and the COVID-19 pandemic have shown that the use of individual, separate tools may not comprehensively cover the entire area of preparedness, especially for unexpected events or expected events of unexpected dimensions. To address this challenge, the article takes up the professional abstract recommendation of ensuring the preparedness of the entire system comprehensively, i.e., by involving all possible tools, knowledge, and resources that the critical entity has. It proposes and tailors a Business Continuity Management System (BCMS) for the energy domain. The approach covers the entire management system of the organization, in which it establishes, implements, operates, monitors, reviews, maintains, and improves the continuity of activities in terms of key energy system functions. The aim is to ensure the sustainability of the functionality of the given systems within acceptable ranges. The article presents the targeted BCMS targets, building blocks, and representative implementation methods and tools. It is argued that the proposal is ready for application in the specific area of energy critical entities and systems by providing examples of partial implementation.Ministerstvo Vnitra České Republiky, (VK01030014); Ministerstvo Vnitra České RepublikyMinistry of the Interior of the Czech Republic; [VK01030014
Electric and dielectric properties of composites of polyaniline coated short carbon fibers in epoxy resin
No full textConductivity and dielectric properties of composites of short carbon fibers coated with a layer of nonconducting form of polyaniline, polyaniline base, in epoxy matrix in the range of 100 Hz to 1300 MHz has been investigated. Unlike the composites with uncoated filler, the properties of the coated material were quite different and significantly depending on the filler content. The measurement of direct current (DC) conductivity revealed that while the percolation threshold of the uncoated fibers lays between 1-2 wt. % of the filler, for coated particles their nonconducting layer increased this value to ca 16-20 vol. %. Consequently, the conductivity of the composite with 7 vol. % of uncoated particles, i.e. far above the percolation threshold, reached a high value of 2×10-3 S m-1, while at the same filler concentration conductivity of the composite material with coated fibers still occurs in the range below percolation limit with a low conductivity similar to matrix value (≈ 10-11 S m-1). The frequency spectra of complex permittivity indicated that, in spite of different fiber character, the difference in polarization of induced dipoles of coated and uncoated fibers or their clusters is not large. The comparison of composites with coated and uncoated fibers below the percolation limit (7 vol. % for the former and 1 vol. % for the latter), both with high DC resistivity, showed that the AC conductivity of the sample filled with coated fibers rose with frequency more quickly than that containing uncoated fibers. This suggests the composite with coated fibers could be a suitable isolating material in low-frequency range and conducting for high-frequency signals