Dagmar Janacova

Dr. Dagmar Janacova

Tomas Bata University in Zlin, Faculty of Applied Informatics, Nad Stranemi 4511, 76005 Zlin, Czech Republic

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

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

Representative Publications

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23 January 2020 in Molecules
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Journal Article
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Robert GalRobert Gal
Robert Gal
Pavel MokrejšPavel Mokrejš
Pavel Mokrejš
PMPetr Mrázek
Petr Mrázek
JPJana Pavlačková
Jana Pavlačková
DJDagmar Janacova
Dagmar Janacova
JOJana Orsavová
Jana Orsavová
Every year, the poultry industry produces a large number of by-products such as chicken heads containing a considerable proportion of proteins, particularly collagen. To prepare gelatin is one of the possibilities to advantageously utilize these by-products as raw materials. The aim of the paper was to process chicken heads into gelatins. An innovative method for conditioning starting raw material was using the proteolytic enzyme. Three technological factors influencing the yield and properties of extracted gelatins were monitored including the amount of enzyme used in the conditioning of the raw material (0.4% and 1.6%), the time of the conditioning (18 and 48 h), and the first gelatin extraction time (1 and 4 h). The gelatin yield was between 20% and 36%. The gelatin gel strength ranged from 113 to 355 Bloom. The viscosity of the gelatin solution was determined between 1.4 and 9.5 mPa.s. The content of inorganic solids varied from 2.3% to 3.9% and the melting point of the gelatin gel was recorded between 34.5 and 42.2 °C. This study has shown that gelatin obtained from chicken heads has a promising potential with diverse possible applications in the food industry, pharmacy, and cosmetics.

12 January 2021 in Molecules
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Pavel MokrejšPavel Mokrejš
Pavel Mokrejš
Robert GalRobert Gal
Robert Gal
JPJana Pavlačková
Jana Pavlačková
DJDagmar Janacova
Dagmar Janacova
In recent decades, food waste management has become a key priority of industrial and food companies, state authorities and consumers as well. The paper describes the biotechnological processing of mechanically deboned chicken meat (MDCM) by-product, rich in collagen, into gelatins. A factorial design at two levels was used to study three selected process conditions (enzyme conditioning time, gelatin extraction temperature and gelatin extraction time). The efficiency of the technological process of valorization of MDCM by-product into gelatins was evaluated by % conversion of the by-product into gelatins and some qualitative parameters of gelatins (gel strength, viscosity and ash content). Under optimal processing conditions (48–72 h of enzyme conditioning time, 73–78 °C gelatin extraction temperature and 100–150 min gelatin extraction time), MDCM by-product can be processed with 30–32% efficiency into gelatins with a gel strength of 140 Bloom, a viscosity of 2.5 mPa.s and an ash content of 5.0% (which can be reduced by deionization using ion-exchange resins). MDCM is a promising food by-product for valorization into gelatins, which have potential applications in food-, pharmaceutical- and cosmetic fields. The presented technology contributes not only to food sustainability but also to the model of a circular economy.

9 June 2022 in ISA Transactions
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SESamuel Emebu
Samuel Emebu
MKMarek Kubalčík
Marek Kubalčík
CBChristoph Josef Backi
Christoph Josef Backi
DJDagmar Janacova
Dagmar Janacova

1 September 2019 in Research Papers Faculty of Materials Science and Technology Slovak University of Technology
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RBRoman Budjac
Roman Budjac
MNMarcel Nikmon
Marcel Nikmon
PSPeter Schreiber
Peter Schreiber
BZBarbora Zahradníková
Barbora Zahradníková
DJDagmar Janacova
Dagmar Janacova
This paper aims at deeper exploration of the new field named auto-machine learning, as it shows promising results in specific machine learning tasks e.g. image classification. The following article is about to summarize the most successful approaches now available in the A.I. community. The automated machine learning method is very briefly described here, but the concept of automated task solving seems to be very promising, since it can significantly reduce expertise level of a person developing the machine learning model. We used Auto-Keras to find the best architecture on several datasets, and demonstrated several automated machine learning features, as well as discussed the issue deeper.

Verified
Journal Article
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Robert GalRobert Gal
Robert Gal
Pavel MokrejšPavel Mokrejš
Pavel Mokrejš
JPJana Pavlačková
Jana Pavlačková
DJDagmar Janacova
Dagmar Janacova
Byproducts obtained from fish processing account for up to 70% of their live weight and represent a large amount of unused raw materials rich in proteins, fats, minerals, and vitamins. Recently, the management of the use of predominantly cold-water fish byproducts has become a priority for many processing companies. This paper describes the biotechnological processing of byproducts of warm-water Cyprinus carpio skeletons into gelatins. A Taguchi experimental design with two process factors (HCl concentration during demineralization of the starting material and the amount of enzyme during enzyme conditioning of the collagen) examined at three levels (0.5, 1.0 and 2.0 wt%; 0.0, 0.1 and 0.2 wt% respectively) was used to optimize the processing of fish tissue into gelatin. Depending on the preparation conditions, four gelatin fractions were prepared by multi-stage extraction from the starting material with a total yield of 18.7–55.7%. Extensive characterization of the gel-forming and surface properties of the prepared gelatins was performed. Gelatins belong to the group of zero–low-medium Bloom value (0–170 Bloom) and low–medium viscosity (1.1–4.9 mPa·s) gelatins and are suitable for some food, pharmaceutical, and cosmetic applications. During processing, the pigment can be isolated; the remaining solid product can then be used in agriculture, and H3PO4Ca can be precipitated from the liquid byproduct after demineralization. The carp byproduct processing technology is environmentally friendly and meets the requirements of zero-waste technology.

31 October 2018 in Cosmetics
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Pavel MokrejšPavel Mokrejš
Pavel Mokrejš
JPJana Pavlačková
Jana Pavlačková
DJDagmar Janacova
Dagmar Janacova
MHMatouš Huťťa
Matouš Huťťa
Although keratin hydrolysates (KH) are added to skin care agents, detailed studies on the moisturising effects of KH are lacking. The aim of this study is to test whether adding KH into an ointment base (OB) heighten hydration of the skin and diminish transepidermal loss of water (TEWL). Formulations containing 2%, 4%, and 6% of KH (based on OB weight) were prepared. Hydration, TEWL and skin pH were measured; intervals of measurements were as follows: 1, 2, 3, 4, 24 and 48 h. Testing was carried out on 10 men. In terms of hydration, supplementing the OB with 2% KH is optimal, as an 11–19% increase occurs in hydration of stratum corneum (SC). All the formulations with added KH as tested caused TEWL to decline after application. Keratin hydrolysate makes for an excellent occlusive; adding it to OB results in a 30–50% reduction in TEWL after application. KH functions as a humectant as well, as it helps to bind water from the lower layers of the epidermis to the SC. Formulations with additions of 2–6% of KH were stable in structure and did not cause phase separation even after 6 months storage.