Marek Doležal

Prof. Dr. Marek Doležal

orcid

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

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

Representative Publications

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28 March 2024 in Agriculture
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KNKristina Nakonechna
Kristina Nakonechna
VIVojtech Ilko
Vojtech Ilko
MBMarkéta Berčíková
Markéta Berčíková
VVVladimir Vietoris
Vladimir Vietoris
ZPZdeňka Panovská
Zdeňka Panovská
Marek DoležalMarek Doležal
Marek Doležal
In the quality monitoring of 18 sunflower oil samples from the EU market, 14 were refined and 4 were cold-pressed. They demonstrated high quality of technological processing with low values of trans-unsaturated fatty acids, acid value, and peroxide value and also met the limits set by legislation in the content of process contaminants 3-monochloropropane-1,2-diol (3-MCPD) esters and glycidyl esters. Measurements of oxidative stability showed a difference in utility value. The average induction period of the oils from the traditional varieties was 2.6 h, predisposing them to cold cooking or short-term frying, while the 11.8 h of the four high oleic sunflower oils (HOSO) indicates the possibility of long-term heat stress. The nutritional benefit is the average vitamin E content of 663 mg/kg oil. The overall sensory quality of the samples was evaluated by a 12-member panel of trained assessors. On the seven-point category scale, the oils were of good to exceptional quality. The cold-pressed oils (CPOs) differed in having, on average, lower trans-unsaturated fatty acid content, process contaminants at unmeasurable levels, and, on average, higher vitamin E concentrations. The specific organoleptic properties of the CPOs were characterized by a pleasant nutty and sunflower seed flavor.

27 September 2022 in Journal of Food Quality
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BPBarbora Pohořelá
Barbora Pohořelá
TGTomáš Gramblička
Tomáš Gramblička
Marek DoležalMarek Doležal
Marek Doležal
DDDarina Dvořáková
Darina Dvořáková
JPJana Pulkrabova
Jana Pulkrabova
JPJan Pánek
Jan Pánek
Atlantic salmon represents an important source of valuable proteins and lipids rich in n-3 fatty acids and micronutrients. However, there are reports that these marine fish still contain contaminants at levels that raise health concerns. Although the Stockholm Convention already bans some compounds, they can still be detected because of their persistence. The present study reports nutritional parameters and the occurrence of persistent and bioaccumulative chemicals in the tissues of fifty-five salmon from several major farming areas. The protein content of all samples was almost identical, averaging to 19.2% w/w, while lipids averaged 14.9% w/w. Fish from Chilean farms contained 6.0% less fat and a lower level of vitamin E than from other sources, that is, 2.2 mg per 100 g (w/w). Fish from Scottish farms contained higher levels of eicosapentaenoic and docosahexaenoic acid. Halogenated contaminants from polychlorinated biphenyls, organochlorinated pesticides, brominated flame retardants, and perfluoroalkylated and polyfluoroalkylated substances were measured, and generally, they were found to be at very low concentrations that did not exceed the legislation limits applicable in the European Union. These results showed that the compositional differences between Atlantic salmon from several important farming areas were only minor, but some significant differences were demonstrated in total fat content and fatty acid profiles.

27 April 2024 in Fermentation
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JBJosef Balak
Josef Balak
LDLucie Drábová
Lucie Drábová
OMOlga Matatkova
Olga Matatkova
Marek DoležalMarek Doležal
Marek Doležal
DMDominik Maršík
Dominik Maršík
IKIrena Jarošová Kolouchová
Irena Jarošová Kolouchová
The specific sensory properties attributed to distillates from different plum varieties are intricately linked to aromatic substances, fruit quality, and technology employed during production. This study compares four plum brandies, each made from a renowned plum variety: Presenta, Valjevka, Čačanská lepotica, and Čačanská rodná on a production scale. Analytical and sensory profiles were assessed using GC-FID, an available analytical method advantageous for monitoring industrial fruit distillate production. Between 71 and 85 analytes were detected in the distillates, with the Presenta plum distillate containing the highest number of substances. Statistically significant differences in analyte concentration between plum varieties (p < 0.05) were observed for 11 analytes. The comparison of analytical profiles and sensory evaluation revealed that a high concentration of 1-propanol, despite its negative sensory perception, significantly impacts the overall perception of a distillate, contrasting with substances like acetaldehyde and propyl acetate, which have positive sensory evaluations but lesser significance in content. Our work identified key compounds and procedures that can be used as benchmarks for production of plum brandy with positive sensory evaluation. These findings demonstrate the broad application potential of GC-FID in fruit distillate production as an independent tool for aromatic profile assessment and quality control.

27 April 2022 in Czech Journal of Food Sciences
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BPBarbora Pohořelá
Barbora Pohořelá
APAndrea Poláchová
Andrea Poláchová
MRMarkéta Růžičková
Markéta Růžičková
Marek DoležalMarek Doležal
Marek Doležal
JPJana Pulkrabova
Jana Pulkrabova
JPJan Pánek
Jan Pánek
Nutritional evaluation of the full-day diet | Barbora Pohořelá, Andrea Poláchová, Markéta Růžičková, Marek Doležal, Jana Pulkrabova, Jan Pánek | Agricultural Journals

21 August 2021 in Applied Sciences
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ZPZdeňka Panovská
Zdeňka Panovská
VIVojtech Ilko
Vojtech Ilko
Marek DoležalMarek Doležal
Marek Doležal
Scientific literature on indoor air quality is categorised mainly into environmental sciences, construction building technology and environmental and civil engineering. Indoor air is a complex and dynamic mixture of a variety of volatile and particulate matter. Some of the constituents are odorous and originate from various sources, such as construction materials, furniture, cleaning products, goods in stores, humans and many more. The first part of the article summarises the knowledge about the substances that are found in the air inside buildings, especially stores, and have a negative impact on our health. This issue has been monitored for a long time, and so, using a better methodology, it is possible to identify even low concentrations of monitored substances. The second part summarises the possibility of using various aromatic substances to improve people’s sense of the air in stores. In recent times, air modification has come to the forefront of researchers’ interest in order to create a more pleasant environment and possibly increase sales.

2 November 2023 in Applied Sciences
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VIVojtech Ilko
Vojtech Ilko
DSDominika Sosnová
Dominika Sosnová
PHPetra Hrůšová
Petra Hrůšová
JFJakub Fišnar
Jakub Fišnar
ŠCŠtěpán Czornyj
Štěpán Czornyj
ZRZuzana Reblová
Zuzana Reblová
Vitamin E, as the most important lipophilic antioxidant of eukaryotic cells, plays an important role in human nutrition. So far, information has focused on the content of vitamin E in raw food materials or foods, and its losses under various processes and culinary treatments. However, the different degradation rates of its eight different forms, four tocopherols and four tocotrienols, during the preparation of oven-ready products have not been clearly and in detail described. Therefore, the aim of our research was to determine the changes in the content of tocochromanols and to evaluate the risks of the loss of these substances while preparing frozen French fries baked in classic and microwave ovens. The tocochromanols were determined using reverse-phase high-performance liquid chromatography with an amperometric detector. The results showed a statistically insignificant loss of γ-tocopherol (γ-T), δ-tocopherol (δ-T), γ-tocotrienol (γ-T3) and δ-tocotrienol (δ-T3). Conversely, the losses of α-tocopherol (α-T), α-tocotrienol (α-T3), the total content of tocochromanols and the vitamin E content in α-tocopherol equivalents (α-TE) were statistically significant (p < 0.01). These losses were independent of the type of baking (conventional heating, heating with air circulation, grill, microwave heating, microwave and grill heating) and averaged at 0.80 mg/kg of the original fries (9.1% of the original content) for α-T, 0.44 mg/kg (36.6%) for α-T3, 1.11 mg/kg (12.7%) for the sum of the tocochromanols and 0.92 mg/kg (12.6%) for the vitamin E content expressed as α-TE. These dishes contained 0.4% to 26% of the daily requirement of vitamin E, based on a 100 g portion, depending on the fat used in the manufacture of the products. The choice of the right frying medium on the part of the manufacturer can increase the content of vitamin E both in the semi-finished product and in the final food, and consequently also its dietary intake.