Veronika Valková

Dr. Veronika Valková

orcid

Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
4 March 2020 in Foods
Verified
Journal Article
Open access
PDF file
Miroslava KačániováMiroslava Kačániová
Miroslava Kačániová
LGLucia Galovičová
Lucia Galovičová
EIEva Ivanišová
Eva Ivanišová
Nenad VukovicNenad Vukovic
Nenad Vukovic
Jana LakatošováJana Lakatošová
Jana Lakatošová
Eva TvrdáEva Tvrdá
Eva Tvrdá
The aim of this study was to assess the chemical composition, antioxidant, antimicrobial and antibiofilm activity of the Coriandrum sativum essential oil. Changes in the biofilm profile of Stenotropomonas maltophilia and Bacillus subtilis were studied using MALDI-TOF MS Biotyper on glass and wooden surfaces. The molecular differences of biofilms in different days were observed as well. The major volatile compounds of the coriander essential oil in the present study were β-linalool 66.07%. Coriander essential oil radical scavenging activity was 51.05% of inhibition. Coriander essential oil expressed the strongest antibacterial activity against B. subtilis followed by S. maltophilia and Penicillium expansum. The strongest antibiofilm activity of the coriander essential oil was found against S. maltophilia. A clearly differentiated branch was obtained for early growth variants of S. maltophilia in case of planktonic cells and all experimental groups and time span can be reported for the grouping pattern of B. subtilis preferentially when comparing to the media matrix, but without clear differences among variants. The results indicate that coriander was effective against the tested Penicillium expansum in the vapor phase after 14 days with MID50 367.19 and MID90 445.92 µL/L of air.

19 September 2021 in Plants
Verified
Journal Article
Open access
PDF file
LGLucia Galovičová
Lucia Galovičová
PBPetra Borotová
Petra Borotová
VVVeronika Valková
Veronika Valková
Nenad VukovicNenad Vukovic
Nenad Vukovic
MVMilena Vukic
Milena Vukic
Miroslava KačániováMiroslava Kačániová
Miroslava Kačániová
Thymus vulgaris essential oil has potential good biological activity. The aim of the research was to evaluate the biological activity of the T. vulgaris essential oil from the Slovak company. The main components of T. vulgaris essential oil were thymol (48.1%), p-cymene (11.7%), 1,8-cineole (6.7), γ-terpinene (6.1%), and carvacrol (5.5%). The antioxidant activity was 85.2 ± 0.2%, which corresponds to 479.34 ± 1.1 TEAC. The antimicrobial activity was moderate or very strong with inhibition zones from 9.89 to 22.44 mm. The lowest values of MIC were determined against B. subtilis, E. faecalis, and S. aureus. In situ antifungal analysis on bread shows that the vapor phase of T. vulgaris essential oil can inhibit the growth of the microscopic filamentous fungi of the genus Penicillium. The antimicrobial activity against S. marcescens showed 46.78–87.80% inhibition at concentrations 62.5–500 µL/mL. The MALDI TOF MS analyses suggest changes in the protein profile of biofilm forming bacteria P. fluorescens and S. enteritidis after the fifth and the ninth day, respectively. Due to the properties of the T. vulgaris essential oil, it can be used in the food industry as a natural supplement to extend the shelf life of the foods.

15 November 2021 in Phytochemistry Reviews
Verified
Journal Article
Closed access
PDF file
HDHana Duranova
Hana Duranova
VVVeronika Valková
Veronika Valková
LGLucia Gabriny
Lucia Gabriny

8 January 2022 in Agronomy
Verified
Journal Article
Open access
PDF file
VVVeronika Valková
Veronika Valková
HDHana Duranova
Hana Duranova
LGLucia Galovičová
Lucia Galovičová
PBPetra Borotová
Petra Borotová
Nenad VukovicNenad Vukovic
Nenad Vukovic
Miroslava KačániováMiroslava Kačániová
Miroslava Kačániová
Antimicrobial in vitro and in situ efficacies of Cymbopogon citratus essential oil (lemongrass, LGEO) against 17 spoilage microorganisms (bacteria, yeasts and fungi) were evaluated. Additionally, its chemical composition, and antioxidant and antibiofilm activities were investigated. The LGEO exhibited a strong antioxidant activity (84.0 ± 0.1%), and its main constituents were citral (61.5%), geraniol (6.6%) and 1,8-cineole (6.4%). An in vitro antimicrobial evaluation revealed the lowest inhibition zone (1.00 ± 0.00 mm) in Pseudomonas fluorescens, and the highest inhibition zone (18.00 ± 2.46 mm) in Candida krusei. The values for the minimal inhibitory concentration were determined to be the lowest for Salmonella enteritidis and the highest for C. albicans. Furthermore, the concentration of ≥250 µL/L of LGEO suppressed the growth of Penicillium aurantiogriseum, Penicillium expansum, Penicillium chrysogenum and Penicillium italicum. The changes in the molecular structure of the biofilms produced by Pseudomonas fluorescens and Salmonella enteritidis, after their treatment with LGEO, confirmed its action on both biofilm-forming bacteria. Moreover, an in situ antimicrobial activity evaluation displayed the most effective inhibitory effectiveness of LGEO against Micrococcus luteus, Serratia marcescens (250 µL/L) and Penicillium expansum (125, 250 and 500 µL/L) growing on a carrot. Our results suggest that LGEO, as a promising natural antimicrobial agent, can be applied in the innovative packaging of bakery products and different types of vegetables, which combines commonly used packing materials with the addition of LGEO.

30 August 2020 in Molecules
Verified
Journal Article
Open access
PDF file
Miroslava KačániováMiroslava Kačániová
Miroslava Kačániová
Margarita TerentjevaMargarita Terentjeva
Margarita Terentjeva
LGLucia Galovičová
Lucia Galovičová
EIEva Ivanišová
Eva Ivanišová
Jana LakatošováJana Lakatošová
Jana Lakatošová
Nenad VukovicNenad Vukovic
Nenad Vukovic
The main aim of the study was to investigate the chemical composition, antioxidant, antimicrobial, and antibiofilm activity of Citrus aurantium essential oil (CAEO). The biofilm profile of Stenotrophonomonas maltophilia and Bacillus subtilis were assessed using the mass spectrometry MALDI-TOF MS Biotyper and the antibiofilm activity of Citrus aurantium (CAEO) was studied on wood and glass surfaces. A semi-quantitative composition using a modified version was applied for the CAEO characterization. The antioxidant activity of CAEO was determined using the DPPH method. The antimicrobial activity was analyzed by disc diffusion for two biofilm producing bacteria, while the vapor phase was used for three penicillia. The antibiofilm activity was observed with the agar microdilution method. The molecular differences of biofilm formation on different days were analyzed, and the genetic similarity was studied with dendrograms constructed from MSP spectra to illustrate the grouping profiles of S. maltophilia and B. subtilis. A differentiated branch was obtained for early growth variants of S. maltophilia for planktonic cells and all experimental groups. The time span can be reported for the grouping pattern of B. subtilis preferentially when comparing to the media matrix, but without clear differences among variants. Furthermore, the minimum inhibitory doses of the CAEO were investigated against microscopic fungi. The results showed that CAEO was most active against Penicillium crustosum, in the vapor phase, on bread and carrot in situ.

6 May 2022 in Plants
Verified
Journal Article
Open access
PDF file
VVVeronika Valková
Veronika Valková
HDHana Duranova
Hana Duranova
MHMichaela Havrlentová
Michaela Havrlentová
EIEva Ivanišová
Eva Ivanišová
Jan MezeyJan Mezey
Jan Mezey
Miroslava KačániováMiroslava Kačániová
Miroslava Kačániová
The present article aimed to study the effects of four selected concentrations (1%, 2%, 5%, and 10%) of apple pomace powder (APP), obtained from juice production, on the nutritional value and selected physico-chemical, antioxidant, and sensory properties of wheat bread. We have found that the ash and total carbohydrate contents, total polyphenols content, and antioxidant activity of the supplemented bread loaves were markedly higher (p < 0.05) as compared to the control ones. On the other hand, values for protein and fat contents and loaf volume in APP-containing bread samples were statistically lower (p < 0.05). Finally, sensory evaluation revealed no significant differences in all tested attributes between the investigated groups of bread samples. The current results suggest that 10% APP addition appears to be an attractive ingredient applied to bread formulation to obtain a bakery product with high nutritional value and required qualitative and sensory properties. In such a manner, apple pomace as by-products from apple juice processing can be efficiently utilized in an eco-friendly way by the food industry to decrease unnecessary waste and environmental pollution.